Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies

Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research article Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies Weilian Geng, Changxing Chen, Xingfeng Sun, Shaoqiang Huang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-52905/v3 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Jan, 2021 Read the published version in BMC Anesthesiology → Version 3 posted 4 You are reading this latest preprint version Show more versions Abstract Background The results of studies on changes in intracranial pressure in patients undergoing laparoscopic surgery are inconsistent. Meanwhile, previous neurosurgery studies have suggested that propofol and sevoflurane have inconsistent effects on cerebral blood flow and cerebrovascular self-regulation. The purpose of this study is to compare changes in the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery under anesthetic maintenance with propofol versus sevoflurane. Methods This study included 110 patients undergoing laparoscopic gynecological surgery with an estimated operative time of more than 2 hours under general anesthesia. The study was a randomized controlled study. The optic nerve sheath diameter（ONSD）at various time points was measured by ultrasound, including when the patients entered the operating room (Tawake), after successful anesthesia induction and endotracheal intubation (Tinduction), when the body position was adjusted to the Trendelenburg position and the CO 2 pneumoperitoneum pressure reached 14 mmHg, which was recorded as T 0 . Then, measurements were conducted every 15 minutes for the first 1 hour and then once every hour until the end of the surgery（T 15 ,T 30 ,T 45 ,T 1h ,T 2h …）, after the end of surgery and the tracheal tube was removed (T end ), and before the patients were transferred to the ward (T pacu ). Results A significant difference in optic nerve sheath diameter was found between two groups at T 15 , T 30 , T 45 (4.64±0.48mm and 4.50±0.29mm, respectively, p=0.031;4.77±0.45mm and 4.62±0.28mm, respectively, p=0.036;4.84±0.46mm and 4.65±0.30mm, respectively, p=0.012), while there was no significant difference at T awake and other time points. Conclusion During laparoscopic gynecological surgery lasting more than 2 hours, the optic nerve sheath diameter was slightly larger in the propofol group than that in the sevoflurane group in the first 45 minutes. No significant difference was observed between the two groups 1 hour after surgery. Trial registration clinicaltrials.gov，NCT03498235. Retrospectively registered 1 March2018,https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0007UMM&selectaction=Edit&uid=U00040C5&ts=39&cx=c7i8ic The manuscript adheres to CONSORT guidelines. Anesthesiology & Pain Medicine optic nerve sheath diameter ONSD sevoflurane propofol CO2 pneumoperitoneum Trendelenburg position Figures Figure 1 Figure 2 Figure 3 Figure 4 Background During laparoscopic gynecological surgery, due to the CO 2 pneumoperitoneum and the steep Trendelenburg position (with the head lowered 45 degrees and the feet raised), cerebral venous recirculation becomes obstructed, and cerebral venous pressure increases. Meanwhile, intra-abdominal pressure increases, cerebrospinal fluid (CSF) absorption decreases, and intracranial pressure increases [1-2]. The CO 2 pneumoperitoneum causes hypercapnia, cerebrovascular dilation, increased intracranial cerebral blood flow, and increased intracranial pressure [3]. Although these effects rarely result in serious neurological complications such as cerebral haemorrhage and cerebral oedema [4], mild neurological complications, such as nausea, vomiting, and headaches, occur sometimes [5]. The results of different studies on changes in intracranial pressure in patients undergoing laparoscopic surgery are not consistent. Kim et al. compared patients undergoing laparoscopic gynecological surgery and laparoscopic gallbladder surgery under desflurane anesthesia and found that the pneumoperitoneum can cause a slight increase in intracranial pressure, but body position did not affect intracranial pressure, and intracranial pressure quickly returned to normal [6]. In a study of patients undergoing robot-assisted laparoscopic prostate surgery under sevoflurane anesthesia, Verdonck et al. found that optic nerve sheath diameter (ONSD) remained unchanged throughout the perioperative period [7]. Propofol and sevoflurane are commonly used anesthetic drugs. Previous neurosurgery studies have suggested that the two drugs have inconsistent effects on cerebral blood flow and cerebrovascular self-regulation [8]. Propofol dose-dependently contracts cerebral blood vessels, inhibits the cerebral oxygen metabolic rate, and reduces intracranial pressure [9,10] but does not affect self-regulation of cerebral blood flow or the responsiveness of cerebral blood vessels to CO 2 [11,12]. Unlike propofol, the effect of sevoflurane on cerebral blood vessels depends on the balance between the direct vasodilating effect and the vasoconstricting effect caused by the reduction in cerebral metabolism [13]. Meanwhile, sevoflurane at a minimum alveolar concentration (MAC) of 0.5-1.5 does not affect self-regulation of cerebral blood flow or the reactivity of cerebral blood vessels to CO 2 [14,15]. It is unclear whether different anesthetic drugs have different effects on intracranial pressure because of the postural position and CO 2 pneumoperitoneum in laparoscopic gynecological surgery. The optic nerve sheath is a continuation of the cerebral dura mater with a transverse subarachnoid space, and its cerebrospinal fluid is also connected to the intracranial subarachnoid space. Therefore, when intracranial pressure increases, ONSD increases [16]. By artificially changing intracranial pressure, Hansen et al. [17] found that there is positive correlation between intracranial pressure and ONSD. Maissan et al. [18] believed that the ONSD could reflect changes in intracranial pressure in real time. Compared with invasive intracranial pressure measurement, the ONSD measured by ultrasound is simpler, non-invasive, and convenient for bedside examination, and changes in intracranial pressure can be observed at any time [18,19]. The purpose of this study is to compare the effects of propofol and sevoflurane on ONSD in patients undergoing laparoscopic gynecological surgery. Methods This is a randomized controlled clinical trial. The ethics committee of Obstetrics and Gynaecology Hospital of Fudan University approved this study. The study was registered with clinicaltrials.gov (NCT03498235). A total of 110 patients who were classified as class I-II according to the standards and guidelines of the American Society of Anaesthesiologists (ASA) and underwent elective laparoscopic gynecological surgery under general anesthesia for an estimated operative time >2 hours from February 2018 to June 2020 were included in the study. The patients were randomly divided into the propofol group (Group P) or the sevoflurane group (Group S). Patients were randomized in a 1:1 ratio occurred by computerized sequence generation. An anesthesiologist, who was not involved in the study, created sealed opaque envelopes in which groupings were written randomized. Envelopes were opened in sequential order only after a patient had signed the consent form. The exclusion criteria were as follow: operative time <2 hours; body mass index (BMI) <18.5 kg/m 2 or ≥24 kg/m 2 ; liver or kidney disease or abnormal results for related laboratory tests (C-reactive protein, hemoglobin, electrolytes, liver and kidney function, international normalized ratio, etc.); neuromuscular disease; allergies to anesthetics; pregnancy; and ophthalmological diseases. The patients did not receive any preoperative drugs and were routinely monitored for non-invasive blood pressure, electrocardiography, and oxygen saturation. All patients received propofol ，sufentanil 0.5 µg/kg and cisatracurium 0.1 mg/kg by intravenous injection for anesthesia induction and endotracheal intubation. TCI system was used for propofol, the target concentrations of propofol during anesthesia induction and maintenance were 4µg/ml and 3.2µg/ml, respectively. After successful intubation, mechanical ventilation was initiated in volumetric control mode, with a tidal volume of 6-8 ml/kg and a respiratory rate of 10-12 breaths/minute while no PEEP in all patients. The tidal volume and respiratory rate were adjusted to maintain an end-tidal CO 2 of 35-40 mmHg. In the sevoflurane group, sevoflurane was maintained at 1–1.5 minimal alveolar concentration (MAC) in 50% oxygen/ air. Remifentanil at 0.25 µg·kg-1·min-1 and intermittent cisatracurium injections were used for anesthetic maintenance. The infusion rate of propofol or the concentration of sevoflurane was adjusted according to a Bispectral index (BIS) of 40-60. Thirty minutes before the end of the surgery, ondansetron was administered to prevent postoperative nausea and vomiting, and 4 mg of oxycodone was administered intravenously to relieve postoperative pain. The medications were discontinued immediately upon completion of the surgery. When the patient was awake, the tidal volume was greater than 6 L/min, and the respiratory rate was 14~20 breaths/min with no PEEP; the endotracheal tube had been removed. Afterwards, the endotracheal tube was removed, the patient was routinely monitored in the post-anesthetic recovery room（PACU） for 1 hour. If the intraoperative mean arterial pressure（MAP） was lower than 90 mmHg or decreased by >30% from the baseline value, then a bolus of 100 µg of phenylephrine was administered. If the heart rate was less than 50 beats/minute, then 0.5 mg of atropine was administered. The angle of the Trendelenburg position adopted in the operation was 30°, and the CO 2 pneumoperitoneum pressure was maintained at 14 mmHg. Patients were excluded from analysis due to intraoperative changes in surgical methods, such as conversion to vaginal surgery or transabdominal surgery, subcutaneous carbon dioxide emphysema development intraoperatively, and intraoperative changes in the anesthetic maintenance drugs. Ultrasound (SonoSite M-Turbo, USA) was used for ONSD measurement. The patient assumed the supine position with the head in the middle position and the eyes gently closed. A disposable transparent patch was used to protect patient’s eyes. An ultrasound-coupling agent was evenly applied to both eyes and the ultrasonic probe. The 6-15Hz high-frequency ultrasonic probe was gently placed above the upper eyelids without applying pressure to the globe. On the ultrasound screen, we can see a "long strip" hypoechoic area, which is perpendicular to the eyeball.The sheath structure with high echo can be seen at the edge of hypoechoic area. ONSD refers to the distance between the high echo sheath structures.The ONSD was measured at 3 mm behind the lateral edge of eyeball. The images of left and right eyes were obtained three times separately at one time point, and all images were stored in DICOM and jpeg formats. A trained anaesthesiologist who was blinded for group allocation took the images of optic nerve sheath in all patients in this study，and ONSD was measured based on stored images by an experienced ultrasound doctor, and the average value was taken, with an accuracy of 0.1 mm. Previous studies have suggested that no significant difference in ONSD exists between different surveyors [20], and trained doctors can also accurately measure the ONSD by ultrasound at the bedside [21]. The primary outcome is to compare the effects of propofol and sevoflurane on ONSD at different time points .The time points at which the ONSD was ultrasonically measured were when the patients entered the operating room (T awake ), after anesthesia induction and endotracheal intubation (T induction ), and when the body position was adjusted to the Trendelenburg position and the CO 2 pneumoperitoneum pressure reached 14 mmHg, which was recorded as T 0 . Then, the ONSD was measured every 15 minutes for the first hour followed by every hour until the end of the surgery（T 15 ,T 30 ,T 45 ,T 1h ,T 2h …）, after anesthesia and drug discontinuation and extubation (T end ), and immediately before transfer from the anesthesia recovery room to the ward (T pacu ). Each time that the ONSD was measured by ultrasound, MAP and BIS was recorded. 1.4 Statistical Analysis The quantitative data with a normal distribution were expressed as the mean ± standard deviation, while the quantitative data with a non-normal distribution were expressed as the median (interquartile range, IQR). Analysis of variance was conducted on repeated measurement data within the groups, and the Student-Newman-Keuls (SNK) q test was used for comparisons between the two groups. P values were adjusted by Bonferroni correction. P<0.05 was considered statistically significant. The early stage of sample size calculation included 15 female patients in the preliminary experiment. The standard deviation of ONSD preoperatively when the patients were conscious was 0.42 mm. According to the research results of Hansen et al. [17], every 1-mmHg increase in intracranial pressure corresponds to a 0.025-mm increase in the ONSD. Consistent with the study of Robba et al. [22], we believe that variation in the ONSD greater than 0.25 mm is clinically significant. At the levels of α=0.05 and β=0.1, the sample size of each group was calculated to be at least 48 cases. Considering the likelihood that approximately 25% of the patients would withdraw from the study, 55 cases were needed for each group. Results Among the 120 female patients who underwent elective laparoscopic gynecological surgery, due to not meeting inclusion criteria or refusing to participate, 116 patients were included in this study, with 58 patients in each group. Due to CO 2 pneumoderma or changes in surgical methods, 55 cases in each group were finally analysed (Fig. 1). The general conditions of the patients are shown in Table 1. Table 1 Baseline Characteristics Group P (n=55) Group S (n=55) P Age(y) 40.53±11.08 41.15±10.26 0.762 Height(cm) 161.18±4.20 159.79±4.50 0.097 Weight(kg) 59 （ 54.5 ， 63 ） 56 （ 51.9 ， 60 ） 0.057 BMI(kg/m2) 22.74±2.28 22.31±2.15 0.262 Surgery duration(h) 2.33 （ 2.12 ， 2.75 ） 2.5 （ 2.22 ， 2.75 ） 0.165 Total blood loss(ml) 100 （ 50 ， 120 ） 80 （ 50 ， 100 ） 0.424 Urine volume （ ml ） 400 （ 300 ， 500 ） 400 （ 400 ， 500 ） 0.088 Fluid volume(ml) 1200 （ 1100 ， 1500 ） 1200(1100,1500 ） 0.645 Airway pressure (mmHg) 15 （ 13 ， 16 ） 15 （ 13 ， 16 ） 0.754 The quantitative data with a normal distribution were expressed as mean ± standard deviation The quantitative data with a non-normal distribution were expressed as median (interquartile range,IQR) BMI Body mass index The comparison of the ONSD at each time point between the two groups is shown in Table 2 and Fig. 2. No significant difference in the baseline preoperative ONSD was found between the two groups. After anesthesia induction, the ONSD values all decreased compared to the baseline value in both two groups, but no significant differences between the two groups. At three time points (T awake , T induction , and T 0 ), the ONSD was not significantly different between the two groups (p = 0.984, 0.666, and 0.646, respectively). Over time, at three time points (T 15 , T 30 , and T 45 ), significant differences in ONSD were identified between the two groups (p= 0.031, 0.035, and 0.028, respectively). At T 1 h , T 2 h , T end , and T pacu , no significant differences in ONSD were found between the two groups after statistical correction (p = 0.065, 0.211, 0.368, and 0.646 respectively). Table 2 Comparison of ONSD at different time points between two groups. Group P (n=55) Group S (n=55) P ONSD T awake （ mm ） 4.39±0.37 4.36±0.45 0.694 ONSD T Induction （ mm ） 4.06±0.45 * 4.05±0.45 * 0.882 ONSD T 0 （ mm ） 4.53±0.47 *# 4.35±0.40 *# 0.058 ONSD T 15 （ mm ） 4.64±0.48 *# 4.50±0.29 *# 0.031 ONSD T 30 （ mm ） 4.77±0.45 *# 4.62±0.28 *# 0.036 ONSD T45 （ mm ） 4.84±0.46 *# 4.65±0.30 *# 0.012 ONSD T 1h （ mm ） 4.83±0.43 *# 4.66±0.28 *# 0.066 ONSD T 2h （ mm ） 4.82±0.41 *# 4.71±0.28 *# 0.089 ONSD T end （ mm ） 4.84±0.44 *# 4.71±0.34 *# 0.082 ONSD T PACU （ mm ） 4.40±0.38 *# 4.36±0.35 *# 0.641 Values were expressed as the mean ± standard variation. * meant comparison of ONSD intra group at each time points to T awake. In Group P, values of p were 0.000 except comparison of T pacu to T awake which p value was 0.945; in Group S, values of p were 0.939 、 0.035 and 0.884 when compared T 0 、 T 15 and T pacu to T awake , while p values were 0.000 at any other time points.# meant comparison of ONSD intra group at each time points to T induction ,and all p values were 0.000 in both two groups. The comparison of the MAP and BIS at each time point between the two groups is shown in Fig.3 and Fig.4.There are no significant differences in MAP and BIS at each time point between Group P and Group S. No hypotension or serious neurological complications such as cerebral haemorrhage or cerebral oedema occurred in either group. Discussion This study compared the effects of two general anesthesia drugs (propofol and sevoflurane) on the ONSD in patients undergoing laparoscopic gynecological surgery. The results showed that the ONSD was significantly reduced compared to the baseline value in the patients in the two groups after anesthesia induction and endotracheal intubation. With establishment of the CO 2 pneumoperitoneum and the Trendelenburg position, the ONSD in both groups increased and exceeded the baseline value. However, at first 45 minutes, the amplitude of the increase in the propofol group was greater than that in the sevoflurane group. Over time, considering the pneumoperitoneum and the Trendelenburg position, no significant difference in the ONSD was found between the two groups from 1 hour after starting the surgery to extubation at the end of the surgery. When leaving the recovery room, the ONSD returned to baseline in the patients in both groups. In this study, both groups received propofol and sufentanil for anesthesia induction, and cisatracurium was used for endotracheal intubation. Both sufentanil and propofol contract cerebral vessels and reduce the cerebral metabolic rate [9,10, 23]; therefore, the ONSD after anesthesia induction was reduced compared to the baseline value. With establishment of the CO 2 pneumoperitoneum and the Trendelenburg position, the ONSD increased gradually but recovered to baseline by 1 hour after surgery. The reason may be that the effect of the CO 2 pneumoperitoneum and body position on intracranial pressure exceeds the effect of drugs on intracranial blood flow. Bilateral internal cervical vessels and vertebral vessels play an important role in cerebral circulation [24]. After establishment of the CO 2 pneumoperitoneum and the Trendelenburg position, recirculation in the internal jugular vein and vertebral vein was obstructed. At the same time, the mean arterial pressure during establishment of the pneumoperitoneum and positioning was elevated compared to that after anesthesia induction. Whiteley et al. found that the ONSD was positively correlated with the mean arterial pressure [25]. For the propofol group, our results are basically consistent with those of Blecha et al. [26]; however, the amplitude of changes in the optic nerve sheath was higher than that in the study of Blecha et al., and maybe the reason for the difference is that the patients in the study of Blecha et al. received midazolam before surgery, which can reduce intracranial pressure. In addition, the patients in that study were from western countries, and the ONSD varied among different races. Wang et al. found that among the Chinese population, the predicted cut-off value of ONSD that means intracranial pressure higher than 20 cmH 2 O was lower than that in Caucasians [27]. The effects of CO 2 pneumoperitoneum and Trendelenburg position establishment on the ONSD in sevoflurane versus propofol anesthesia are different in various studies. We found that although the ONSD increased in the sevoflurane group, the amplitude of the increase was smaller than that in the propofol group at the early stage of surgery. In the study of Robba et al. [22], the amplitude of the increase in the ONSD after sevoflurane anesthesia was consistent with that in our study. However, the studies of Kim et al. [28] and Chin et al. [29] showed that the amplitude of the increase in the ONSD after sevoflurane anesthesia was higher than that in our study. Verdonck et al. [7] believed that the ONSD remains unchanged in patients undergoing sevoflurane anesthesia. The results of this study are generally consistent with those of Lee et al [30], while in the first 30 minutes of operation,the results were inconsistent. The main reason may be that Lee et al. used midazolam and glinbromide before operation; on the other hand, study of Lee et al only maintained BIS at 40-60 during the whole operation, but did not compare the BIS values between the two groups. The depth of anesthesia may affect the changes of cerebral blood flow, thus further affecting the changes of intracranial pressure and ONSD value. The inconsistencies across different studies may be due to the lack of consistency in patients’ anesthetic depth and sevoflurane blood concentration. Sevoflurane has a dominant effect on cerebral oxygen metabolism at a low concentration; while at medium and high concentrations, it has a direct vasodilatory effect [31]. Propofol reduces cerebral blood flow more because of its effect on reducing cerebral oxygen metabolism rather than direct vasoconstriction [32,33]. Meanwhile, the ONSD can reflect intracranial pressure in real time; however, the correlation coefficient between ONSD and intracranial pressure in previous studies was 0.660-0.820 [19,34,35]. Hansen et al. believed that the ONSD and intracranial pressure have an elastic nonlinear relationship [17]. In other words, the ONSD may better reflect changing trends in intracranial pressure than specific values. We found that although the ONSD increased significantly in both groups, it returned to baseline 1 hour after surgery. Animal studies suggest that with establishment of the CO 2 pneumoperitoneum and the Trendelenburg position, intracranial pressure increased by 10 mmHg compared to the baseline value [36]. However, Kalmar et al. [37] believe that intracranial pressure fluctuations within the physiological range are regulated by multiple mechanisms，and that the intracranial pressure increases exponentially only when these regulatory mechanisms are exhausted. Notably, the brain has a strong ability to transfer CSF to the vascular system, and when intracranial pressure increased, CSF moved intrathecally at a rate of 2 ml/min [38，39], which is also why the ONSD returned to baseline 1 hour after surgery. On the other way, a reduction of the intracranial blood volume after termination of the steep Trendelenburg position could be the reason. Four limitations exist in this study. First, this study did not analyse changes in the ONSD in patients with longer operative times (>3 hours), mainly because few cases required long operative times (>3 hours) in this study. Hansen et al. suggested that prolonged intracranial hypertension affected the reversibility of optic nerve sheath changes [17]. Therefore, we hypothesized that the duration of the increase in ONSD in patients undergoing prolonged laparoscopic gynecological surgery would be prolonged, but further studies are needed for confirmation. Second，all the patients included in this study were female patients younger than 65 years old, and further studies are needed to determine whether similar conclusions can be established for male or elderly patients. Third, in our study, sevoflurane was maintained at 1–1.5 minimal alveolar concentration (MAC) while we do not record values of end-tidal concentrations of sevoflurane (Etsevo). Animal studies suggest that cerebral blood flow may not be changed when Etsevo is 0.3-1.5MAC[40]. Artru et al find ICP is not changed when sevoflurane is 0.5MAC、1.0MAC or 1.5MAC in neurosurgery patients[41].We guess that small changes in Etsevo during 0.5-1.5MAC may not have significant effects on cerebral blood flow .Fourth, Whiteley et al suggest that ONSD is positively correlated with MAP[25].In our study ,there are no significant differences between Group S and Group P at different time points and that is why we ignore the effect of blood pressure on ONSD. In conclusion, we found that when comparing the two drugs, at the early stage, the ONSD post-pneumoperitoneum in the propofol group was slightly larger than that in the sevoflurane group, and the difference was statistically significant. No significant difference was observed between the two groups 1 hour after surgery. Abbreviations optic nerve sheath diameter ONSD;American Society of Anaesthesiologists ASA;mean arterial pressure MAP; Bispectral index BIS;minimal alveolar concentration MAC; post-anesthetic recovery room PACU. Declarations Ethics approval and consent to participate After approval by the ethics committee of Obstetrics and Gynaecology Hospital of Fudan University. The committee’s reference number is 2018-05.We herein confirm written consent obtained from each patient in accordance with the Declaration of Helsinki in order to report and publish the individual patient data obtained. A written consent to participate from each patient in the current study was obtained. Consent for publication Not applicable. Availability of data and materials The trial protocol, datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding Not applicable. Authors' contributions WG, first author: Study Design, data collection, interpretation, drafting article, critical revision of the article and final approval of the version to be published. CC, co-first author: Study Design, references review, data analysis, drafting article, critical revision of the article and final approval of the version to be published. XS, second author: Study Design, critical revision of the article and final approval of the version to be published. SH，correspondance author: Study Design, data analysis, critical revision of the article and final approval of the version to be published. Acknowledgements Not applicable. Authors’ informations Weilian Geng , [email protected] , Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China ;Changxing Chen, [email protected] , Emergency and Critical Care Department, Shanghai General Hospital, Shanghai, ChinaXingfeng Sun, [email protected] , Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China ;Shaoqiang Huang, [email protected] , Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China References [1] Fahy BG, Barnas GM, Nagle SE, Flowers JL, Njoku MJ, Agarwal M. Effects of Trendelenburg and reverse Trendelenburg postures on lung and chest wall mechanics. J Clin Anesth 1996;8(3): 236–44. http://doi.org/ 10.1016/0952-8180(96)00017-7 [2] Halverson A, Buchanan R, Jacobs L, et al. Evaluation of mechanism of increased intracranial pressure with insufflation. Surg Endosc 1998; 12: 266-9. http://doi.org/ 10.1007/s004649900648 [3] Lassen NA, Christensen MS. Physiology of cerebral blood flow. Br J Anaesth 1976;48(8):719–34. http://doi.org/ 10.1093/bja/48.8.719 [4] R Pandey , R Garg , V Darlong , J Punj , Chandralekha , A Kumar . Unpredicted neurological complications after robotic laparoscopic radical cystectomy and ileal conduit formation in steep trendelenburg position: two case reports. Acta Anaesthesiol Belg 2010; 61: 163–6. PMID: 21268573 [5] Cooke SJ, Paterson-Brown S. Association between laparoscopic abdominal surgery and postoperative symptoms of raised intracranial pressure. Surg Endosc 2001; 15: 723–5. http://doi.org/10.1007/s00464-001-0004-8. [6] Kim SH , Kim HJ , Jung KT . Position does not affect the optic nerve sheath diameter during laparoscopy. Korean J Anesthesiol 2015;68(4):358-63. DOI: https://doi.org/10.4097/kjae.2015.68.4.358 [7] Verdonck P, Kalmar AF, Suy K, et al. Optic nerve sheath diameter remains constant during robot assisted laparoscopic radical prostatectomy. PLoS One 2014; 9: e111916. http://doi.org/ 10.1371/journal.pone.0111916. [8] Conti A, Iacopino DG, Fodale V, Micalizzi S, Penna O, Santamaria LB. Cerebral haemodynamic changes during propofol-remifentanil or sevoflurane anesthesia: transcranial Doppler study under Bispectral Index Monitoring. Br J Anaesth 2006; 97(3):333-9. http://doi.org/ 10.1093/bja/ael169 [9] Oshima T, Karasawa F, Satoh T. Effects of propofol on cerebral blood flow and the metabolic rate of oxygen in humans. Acta Anaesthesiol Scand 2002:46:831–5. http://doi.org/10.1034/j.1399-6576.2002.460713.x [10] Doyle PW, Matta BF. Burst suppression or isoelectric encephalogram for cerebral protection: Evidence from metabolic suppression studies. Br J Anaesth 1999; 83:580–4. http://doi.org/10.1093/bja/83.4.580. [11]Eng C, Lam AM, Mayberg TS, Lee C, Mathisen T.The influence of propofol with and without nitrous oxide on cerebral blood flow velocity and CO, reactivity in humans. Anesthesiology 1992; 77:872-9. http://doi.org/ 10.1097/00000542-199211000-00006 [12]Matta BF, Lam AM, Strebel S, Mayberg TS. Cerebral pressure autoregulation and CO-reactivity during propofol-induced EEG suppression. Br J Anaesth 1995; 74:159-63. http://doi.org/10.1093/bja/74.2.159 [13] Drummond JC , Todd MM , Scheller MS , Shapiro HM . A comparison of the direct cerebral vasodilating potencies of halothane and isoflurane in the New Zealand white rabbit. Anesthesiology 1986; 65(5): 462-7. http://doi.org/ 10.1097/00000542-198611000-00002 [14] Gupta S, Heath K, Matta BF. Effect of incremental doses of sevoflurane on cerebral pressure autoregulation in humans. Br J Anaesth 1997; 79: 469–72. http://doi.org/10.1093/bja/79.4.469 [15] Choi SH , Lee SJ , Rha KH , Shin SK , Oh YJ .The effect of pneumoperitoneum and Trendelenburg position on acute cerebral blood flow–carbon dioxide reactivity under sevoflurane anesthesia. Anesthesia. 2008; 63(12): 1314-8. http://doi.org/10.1111/j.1365-2044.2008.05636.x [16] Killer HE, Laeng HR, Flammer J, Groscurth P.Architecture of arachnoid trabeculae, pillars,and septa in the subarachnoid space of the human optic nerve:anatomy and clinical considerations. Br J Ophthalmol 2003;87(6):777-81. http://doi.org/10.1136/bjo.87.6.777 [17] Hansen HC , Lagrèze W , Krueger O , Helmke K .Dependence of the optic nerve sheath diameter on acutely applied subarachnoidal pressure–an experimental ultrasound study. Acta Ophthalmol 2011;89(6):528-32. http://doi.org/10.1111/j.1755-3768.2011.02159.x [18] Maissan IM, Dirven PJ, Haitsma IK, Hoeks SE, Gommers D, Stolker RJ. Ultrasonographic measured optic nerve sheath diameter as an accurate and quick monitor for changes in intracranial pressure. J Neurosurg 2015;123(3):743-7. http://doi.org/ 10.3171/2014.10.JNS141197 [19] Wang LJ , Yao Y , Feng LS , et al. Noninvasive and quantitative intracranial pressure estimation using ultrasonographic measurement of optic nerve sheath diameter. Sci Rep 2017;7(2):42063. http://doi.org/10.1038/srep42063 [20] Lochner P,Coppo L,Cantello R, et al. Intra- and interobserver reliability of transorbital sonographic assessment of the optic nerve sheathdiameter and optic nerve diameter in healthy adults. J Ultrasound 2014;19(1):41-5. http://doi.org/10.1007/s40477-014-0144-z [21] Hassen GW, Bruck I, Donahue J, et al.Accuracy of optic nerve sheath diameter measurement by emergency physicians using bedside ultrasound. J Emerg Med 2015,48(4):450-457. http://doi.org/10.1016/j.jemermed.2014.09.060 [22]Robba C, Cardim D, Donnelly J, et al. Effects of pneumoperitoneum and Trendelenburg position on intracranial pressure assessed using different non-invasive methods. Br J Anaesth 2016;117 (6): 783-9. http://doi.org/10.1093/bja/aew356 [23] Werner C, Hoffman WE, Baughman VL, Albrecht RF, Schulte J. Effects of sufentanil on cerebral blood flow, cerebral blood flow velocity, and metabolism in dogs. Anesth Analg 1991; 72: 177-81. http://doi.org/10.1213/00000539-199102000-00006 [24] Smith KJ , Wong LE , Eves ND , et al. Regional cerebral blood flow distribution during exercise: influence of oxygen. Respir Physiol Neurobiol 2012;184(1):97-105. http://doi.org/10.1016/j.resp.2012.07.014 [25] Whiteley JR, Taylor J, Henry M, Epperson TI, Hand WR. Detection of elevated intracranial pressure in robot-assisted laparoscopic radical prostatectomy using ultrasonography of optic nerve sheath diameter. J Neurosurg Anesthesiol 2015;27(2):155–9. http://doi.org/10.1097/ANA.0000000000000106 [26] Blecha S , Harth M , Schlachetzki F , et al. Changes in intraocular pressure and optic nerve sheath diameter in patients undergoing robotic-assisted laparoscopic prostatectomy in steep 45° Trendelenburg position.BMC Anesthesiol 2017;11;17(1):40. http://doi.org/10.1186/s12871-017-0333-3 [27] Wang L,Feng L,Yao Y, et al. Optimal optic nerve sheath diameter threshold for the identification of elevated openingpressure on lumbarpuncture in a Chinese population. PLoS One, 2015,10(2):e0117939. http://doi.org/10.1371/journal.pone.0117939 [28] Kim MS, Bai SJ, Lee JR, Choi YD, Kim YJ, Choi SH. Increase in intracranial pressure during carbon dioxide pneumoperitoneum with steep trendelenburg positioning proven by ultrasonographic measurement of optic nerve sheath diameter. J Endourol 2014;28(7):801–6. http://doi.org/10.1089/end.2014.0019 [29] Chin JH, Seo H, Lee EH, et al. Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position. BMC Anesthesiol 2015;15:43. http://doi.org/10.1186/s12871-015-0025-9 [30]Lee YY et al. Optic nerve sheath diameter changes during gynecologic surgery in the Trendelenburg position: comparison of propofol-based total intravenous anesthesia and sevoflurane anesthesia. Anesth Pain Med 2019;14:393-400 [31] Doe A , Kumagai M , Tamura Y , Sakai A , Suzuki K . A comparative analysis of the effects of sevoflurane and propofol on cerebral oxygenation during steep Trendelenburg position and pneumoperitoneum for robotic-assisted laparoscopic prostatectomy. J Anesth 2016 ;30(6):949-55. http://doi.org/10.1007/s00540-016-2241-y [32] Holzer A , Winter W , Greher M , et al. A comparison of propofol and sevoflurane anesthesia: effects on aortic blood flow velocity and middle cerebral artery blood flow velocity. Anesthesia 2003;58(3):217-22. http://doi.org/10.1046/j.1365-2044.2003.03041.x [33] Laaksonen L , Kallioinen M , Långsjö J , et al. Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study. Br J Anaesth 2018;121(1):281-90. http://doi.org/ 10.1016/j.bja.2018.04.008 [34] Raffiz M , Abdullah JM . Optic nerve sheath diameter measurement: a means of detecting raised ICP in adult traumatic and non-traumatic neurosurgical patients. Am J Emerg Med 2017 ;35(1):150-3. http://doi.org/10.1016/j.ajem.2016.09.044 [35] Padayachy LC , Padayachy V , Galal U , Gray R , Fieggen AG . The relationship between transorbital ultrasound measurement of the optic nerve sheath diameter (ONSD) and invasively measured ICP in children: Part I: repeatability, observer variability and general analysis. Childs Nerv Syst 2016;32(10):1769-78. http://doi.org/10.1007/s00381-016-3067-5 [36] Tatebayashi K, Asai Y, Maeda T, Shiraishi Y, Miyoshi M, Kawai Y. Effects of head-down tilt on the intracranial pressure in conscious rabbits. Brain Res 2003;977(1):55-61. http://doi.org/10.1016/s0006-8993(03)02723-9 [37] Kalmar AF, Dewaele F, Foubert L, et al. Cerebral haemodynamic physiology during steep Trendelenburg position and CO(2) pneumoperitoneum. Br J Anaesth 2012;108(3):478-84. http://doi.org/10.1093/bja/aer448 [38] Eklund A, Smielewski P, Chambers I, et al. Assessment of cerebrospinal fluid outflow resistance. Med Biol Eng Comput 2007; 45(8): 719-35. http://doi.org/ 10.1007/s11517-007-0199-5 [39]Kalmar AF, De Ley G, Van Den Broecke C, Van Aken J, Struys MM, et al. Influence of an increased intracranial pressure on cerebral and systemic haemodynamics during endoscopic neurosurgery: an animal model. Br J Anaesth. 2009 Mar;102(3):361-8. [40] Kimme P , Ledin T , Sjöberg F . Dose effect of sevoflurane and isoflurane anesthetics on cortical blood flow during controlled hypotension in the pig. Acta Anaesthesiol Scand. 2007 May;51(5):607-13. [41] Artru AA , Lam AM , Johnson JO , Sperry RJ . Intracranial pressure, middle cerebral artery flow velocity, and plasma inorganic fluoride concentrations in neurosurgical patients receiving sevoflurane or isoflurane. Anesth Analg. 1997 Sep;85(3):587-92. Supplementary Files CONSORT2010Checklist.doc Cite Share Download PDF Status: Published Journal Publication published 27 Jan, 2021 Read the published version in BMC Anesthesiology → Version 3 posted Editorial decision: Accept 10 Jan, 2021 Editor assigned by journal 05 Jan, 2021 Submission checks completed at journal 05 Jan, 2021 Editor invited by journal 05 Jan, 2021 You are reading this latest preprint version Show more versions Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-52905","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":7808782,"identity":"c883339b-77d1-4e84-826c-de628568362f","order_by":0,"name":"Weilian Geng","email":"","orcid":"","institution":"Department of Anesthesia,Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Weilian","middleName":"","lastName":"Geng","suffix":""},{"id":7808783,"identity":"a724529d-c849-4333-9c0c-e33c4e35a517","order_by":1,"name":"Changxing Chen","email":"","orcid":"","institution":"Emergency and Critical Care Department,Shanghai General Hospital","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Changxing","middleName":"","lastName":"Chen","suffix":""},{"id":7808784,"identity":"8876b98e-50aa-4d69-bbf7-9c67c08f841f","order_by":2,"name":"Xingfeng Sun","email":"","orcid":"","institution":"Department of Anesthesia,Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xingfeng","middleName":"","lastName":"Sun","suffix":""},{"id":7808785,"identity":"52eddcfb-f235-4786-ad08-abed46766ed6","order_by":3,"name":"Shaoqiang Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAx0lEQVRIiWNgGAWjYDCCAzxQBntj48MPpGnhOdxsLEGaFon0NgEevEqhgO/22WMSP3fU2vPdfNjGIMFgJ6fbQECL5Lm8NMneM8cTZ95ObHtQwJBsbHaAgBaDMzxmErxtxxIMbie2G0gwHEjcRowWyb9tx+wNbh5sk+AhVos0b1sN44YbjERqkTzDY2wt23YgceaZRGAgGxDhF74zPIY337bV2fMdP/7w4YcKOzmCWqDgMDCCwO4kTjkI1EG1jIJRMApGwSjAAgBkaUaTgvNuDwAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-0515-8099","institution":"Obstetrics and Gynecology Hospital of Fudan University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Shaoqiang","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2020-08-03 11:33:28","currentVersionCode":3,"declarations":"","doi":"10.21203/rs.3.rs-52905/v3","doiUrl":"https://doi.org/10.21203/rs.3.rs-52905/v3","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12871-021-01243-7","type":"published","date":"2021-01-27T15:00:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":4989168,"identity":"9a0701fc-f2b5-475f-bf7c-c4114031d836","added_by":"auto","created_at":"2021-01-15 11:36:39","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":32818,"visible":true,"origin":"","legend":"Flow diagram.","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/0abc0656e284ba329dda77fc.jpg"},{"id":4989272,"identity":"85cbe616-37dd-4180-9561-6f8cd7a530b4","added_by":"auto","created_at":"2021-01-15 11:42:39","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":28062,"visible":true,"origin":"","legend":"Comparison of ONSD at each time points between two groups. ✕ meant there were statistical difference between two groups at time points T15、T30和T45(Values of p were 0.031、0.035 and0.028). Comparison of ONSD at other time points, values of p were 0.984、0.666、0.646、0.065、0.211、0.368 and 0.646 at Tawake、Tinduction、T0、T1h、T2h、Tend and Tpacu.","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/170de5475d79a4a2e135ea35.jpg"},{"id":4989170,"identity":"82157cf9-7804-493d-8c12-aa49a76aba9f","added_by":"auto","created_at":"2021-01-15 11:36:39","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":25472,"visible":true,"origin":"","legend":"Comparison of MAP at each time points between two groups. There are no significant differences between two groups at each time points( Values of p were 0.066、0.312、0.912、0.156、0.125、0.064、0.166、0.095、0.092 and 0.290.).","description":"","filename":"Fig3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/615e765f43120d6e5e2b5323.jpg"},{"id":4989169,"identity":"bab17663-8c04-431d-ab73-9ac1757b893d","added_by":"auto","created_at":"2021-01-15 11:36:39","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":22472,"visible":true,"origin":"","legend":"Comparison of BIS at each time points between two groups. There are no significant differences between two groups at each time points( Values of p were 0.093、0.065、0.191、1.000、0.970、0.503 and 0.368 ).","description":"","filename":"Fig4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/6f50a91ee17ca514785f82f0.jpg"},{"id":13647006,"identity":"6f746a1b-ea3a-48cc-a793-1f5188108cef","added_by":"auto","created_at":"2021-09-17 09:26:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":386247,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/c1f3f675-27ab-4f84-9862-0a3113412eb7.pdf"},{"id":4989172,"identity":"ce9387ef-dd5c-4f7d-8b1d-ff8b078af308","added_by":"auto","created_at":"2021-01-15 11:36:39","extension":"doc","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":221696,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORT2010Checklist.doc","url":"https://assets-eu.researchsquare.com/files/rs-52905/v3/0f3b8d032b0a6000ba1f201d.doc"}],"financialInterests":"","formattedTitle":"Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies","fulltext":[{"header":"Background","content":"\u003cp\u003eDuring laparoscopic gynecological surgery, due to the CO\u003csub\u003e2 \u003c/sub\u003epneumoperitoneum and the steep Trendelenburg position (with the head lowered 45 degrees and the feet raised), cerebral venous recirculation becomes obstructed, and cerebral venous pressure increases. Meanwhile, intra-abdominal pressure increases, cerebrospinal fluid (CSF) absorption decreases, and intracranial pressure increases [1-2]. The CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum causes hypercapnia, cerebrovascular dilation, increased intracranial cerebral blood flow, and increased intracranial pressure [3]. Although these effects rarely result in serious neurological complications such as cerebral haemorrhage and cerebral oedema [4], mild neurological complications, such as nausea, vomiting, and headaches, occur sometimes [5].\u003c/p\u003e\n\u003cp\u003eThe results of different studies on changes in intracranial pressure in patients undergoing laparoscopic surgery are not consistent. Kim et al. compared patients undergoing laparoscopic gynecological surgery and laparoscopic gallbladder surgery under desflurane anesthesia and found that the pneumoperitoneum can cause a slight increase in intracranial pressure, but body position did not affect intracranial pressure, and intracranial pressure quickly returned to normal [6]. In a study of patients undergoing robot-assisted laparoscopic prostate surgery under sevoflurane anesthesia, Verdonck et al. found that optic nerve sheath diameter (ONSD) remained unchanged throughout the perioperative period [7].\u003c/p\u003e\n\u003cp\u003ePropofol and sevoflurane are commonly used anesthetic drugs. Previous neurosurgery studies have suggested that the two drugs have inconsistent effects on cerebral blood flow and cerebrovascular self-regulation [8]. Propofol dose-dependently contracts cerebral blood vessels, inhibits the cerebral oxygen metabolic rate, and reduces intracranial pressure [9,10] but does not affect self-regulation of cerebral blood flow or the responsiveness of cerebral blood vessels to CO\u003csub\u003e2\u003c/sub\u003e [11,12]. Unlike propofol, the effect of sevoflurane on cerebral blood vessels depends on the balance between the direct vasodilating effect and the vasoconstricting effect caused by the reduction in cerebral metabolism [13]. Meanwhile, sevoflurane at a minimum alveolar concentration (MAC) of 0.5-1.5 does not affect self-regulation of cerebral blood flow or the reactivity of cerebral blood vessels to CO\u003csub\u003e2\u003c/sub\u003e [14,15]. It is unclear whether different anesthetic drugs have different effects on intracranial pressure because of the postural position and CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum in laparoscopic gynecological surgery.\u003c/p\u003e\n\u003cp\u003eThe optic nerve sheath is a continuation of the cerebral dura mater with a transverse subarachnoid space, and its cerebrospinal fluid is also connected to the intracranial subarachnoid space. Therefore, when intracranial pressure increases, ONSD increases [16]. By artificially changing intracranial pressure, Hansen et al. [17] found that there is positive correlation between intracranial pressure and ONSD. Maissan et al. [18] believed that the ONSD could reflect changes in intracranial pressure in real time.\u003c/p\u003e\n\u003cp\u003eCompared with invasive intracranial pressure measurement, the ONSD measured by ultrasound is simpler, non-invasive, and convenient for bedside examination, and changes in intracranial pressure can be observed at any time [18,19]. The purpose of this study is to compare the effects of propofol and sevoflurane on ONSD in patients undergoing laparoscopic gynecological surgery.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis is a randomized controlled clinical trial. The ethics committee of Obstetrics and Gynaecology Hospital of Fudan University approved this study. The study was registered with clinicaltrials.gov (NCT03498235). A total of 110 patients who were classified as class I-II according to the standards and guidelines of the American Society of Anaesthesiologists (ASA) and underwent elective laparoscopic gynecological surgery under general anesthesia for an estimated operative time \u0026gt;2 hours from February 2018 to June 2020 were included in the study. The patients were randomly divided into the propofol group (Group P) or the sevoflurane group (Group S). Patients were randomized in a 1:1 ratio occurred by computerized sequence generation. An anesthesiologist, who was not involved in the study, created sealed opaque envelopes in which groupings were written randomized. Envelopes were opened in sequential order only after a patient had signed the consent form.\u0026nbsp; The exclusion criteria were as follow: operative time \u0026lt;2 hours; body mass index (BMI) \u0026lt;18.5 kg/m\u003csup\u003e2 \u003c/sup\u003eor \u0026ge;24 kg/m\u003csup\u003e2\u003c/sup\u003e; liver or kidney disease or abnormal results for related laboratory tests (C-reactive protein, hemoglobin, electrolytes, liver and kidney function, international normalized ratio, etc.); neuromuscular disease; allergies to anesthetics; pregnancy; and ophthalmological diseases.\u003c/p\u003e\n\u003cp\u003eThe patients did not receive any preoperative drugs and were routinely monitored for non-invasive blood pressure, electrocardiography, and oxygen saturation. All patients received propofol ，sufentanil 0.5 \u0026micro;g/kg and cisatracurium 0.1 mg/kg by intravenous injection for anesthesia induction and endotracheal intubation. TCI system was used for propofol, the target concentrations of propofol during anesthesia induction and maintenance were 4\u0026micro;g/ml and 3.2\u0026micro;g/ml, respectively. After successful intubation, mechanical ventilation was initiated in volumetric control mode, with a tidal volume of 6-8 ml/kg and a respiratory rate of 10-12 breaths/minute while no PEEP in all patients. The tidal volume and respiratory rate were adjusted to maintain an end-tidal CO\u003csub\u003e2 \u003c/sub\u003eof 35-40 mmHg. In the sevoflurane group, sevoflurane was maintained at 1\u0026ndash;1.5 minimal alveolar concentration (MAC) in 50% oxygen/ air. Remifentanil at 0.25 \u0026micro;g\u0026middot;kg-1\u0026middot;min-1 and intermittent cisatracurium injections were used for anesthetic maintenance. The infusion rate of propofol or the concentration of sevoflurane was adjusted according to a Bispectral index (BIS) of 40-60. Thirty minutes before the end of the surgery, ondansetron was administered to prevent postoperative nausea and vomiting, and 4 mg of oxycodone was administered intravenously to relieve postoperative pain. The medications were discontinued immediately upon completion of the surgery. When the patient was awake, the tidal volume was greater than 6 L/min, and the respiratory rate was 14~20 breaths/min with no PEEP; the endotracheal tube had been removed. Afterwards, the endotracheal tube was removed, the patient was routinely monitored in the post-anesthetic recovery room（PACU） for 1 hour.\u003c/p\u003e\n\u003cp\u003eIf the intraoperative mean arterial pressure（MAP） was lower than 90 mmHg or decreased by \u0026gt;30% from the baseline value, then a bolus of 100 \u0026micro;g of phenylephrine was administered. If the heart rate was less than 50 beats/minute, then 0.5 mg of atropine was administered. The angle of the Trendelenburg position adopted in the operation was 30\u0026deg;, and the CO\u003csub\u003e2 \u003c/sub\u003epneumoperitoneum pressure was maintained at 14 mmHg. Patients were excluded from analysis due to intraoperative changes in surgical methods, such as conversion to vaginal surgery or transabdominal surgery, subcutaneous carbon dioxide emphysema development intraoperatively, and intraoperative changes in the anesthetic maintenance drugs.\u003c/p\u003e\n\u003cp\u003eUltrasound (SonoSite M-Turbo, USA) was used for ONSD measurement. The patient assumed the supine position with the head in the middle position and the eyes gently closed. A disposable transparent patch was used to protect patient\u0026rsquo;s eyes. An ultrasound-coupling agent was evenly applied to both eyes and the ultrasonic probe. The 6-15Hz high-frequency ultrasonic probe was gently placed above the upper eyelids without applying pressure to the globe. On the ultrasound screen, we can see a \"long strip\" hypoechoic area, which is perpendicular to the eyeball.The sheath structure with high echo can be seen at the edge of hypoechoic area. ONSD refers to the distance between the high echo sheath structures.The ONSD was measured at 3 mm behind the lateral edge of eyeball.\u003c/p\u003e\n\u003cp\u003eThe images of left and right eyes were obtained three times separately at one time point, and all images were stored in DICOM and jpeg formats. A trained anaesthesiologist who was blinded for group allocation took the images\u0026nbsp; of optic nerve sheath in all patients in this study，and ONSD was measured based on stored images by an experienced ultrasound doctor, and the average value was taken, with an accuracy of 0.1 mm. Previous studies have suggested that no significant difference in ONSD exists between different surveyors [20], and trained doctors can also accurately measure the ONSD by ultrasound at the bedside [21].\u003c/p\u003e\n\u003cp\u003eThe primary outcome is to compare the effects of propofol and sevoflurane on ONSD at different time points .The time points at which the ONSD was ultrasonically measured were when the patients entered the operating room (T\u003csub\u003eawake\u003c/sub\u003e), after anesthesia induction and endotracheal intubation (T\u003csub\u003einduction\u003c/sub\u003e), and when the body position was adjusted to the Trendelenburg position and the CO\u003csub\u003e2 \u003c/sub\u003epneumoperitoneum pressure reached 14 mmHg, which was recorded as T\u003csub\u003e0\u003c/sub\u003e. Then, the ONSD was measured every 15 minutes for the first hour followed by every hour until the end of the surgery（T\u003csub\u003e15\u003c/sub\u003e,T\u003csub\u003e30\u003c/sub\u003e,T\u003csub\u003e45\u003c/sub\u003e ,T\u003csub\u003e1h\u003c/sub\u003e ,T\u003csub\u003e2h\u003c/sub\u003e\u0026hellip;）, after anesthesia and drug discontinuation and extubation (T\u003csub\u003eend\u003c/sub\u003e), and immediately before transfer from the anesthesia recovery room to the ward (T\u003csub\u003epacu\u003c/sub\u003e). Each time that the ONSD was measured by ultrasound, MAP and BIS was recorded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.4 Statistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe quantitative data with a normal distribution were expressed as the mean \u0026plusmn; standard deviation, while the quantitative data with a non-normal distribution were expressed as the median (interquartile range, IQR). Analysis of variance was conducted on repeated measurement data within the groups, and the Student-Newman-Keuls (SNK) q test was used for comparisons between the two groups. P values were adjusted by Bonferroni correction. P\u0026lt;0.05 was considered statistically significant.\u003c/p\u003e\n\u003cp\u003eThe early stage of sample size calculation included 15 female patients in the preliminary experiment. The standard deviation of ONSD preoperatively when the patients were conscious was 0.42 mm. According to the research results of Hansen et al. [17], every 1-mmHg increase in intracranial pressure corresponds to a 0.025-mm increase in the ONSD. Consistent with the study of Robba et al. [22], we believe that variation in the ONSD greater than 0.25 mm is clinically significant. At the levels of \u0026alpha;=0.05 and \u0026beta;=0.1, the sample size of each group was calculated to be at least 48 cases. Considering the likelihood that approximately 25% of the patients would withdraw from the study, 55 cases were needed for each group.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eAmong the 120 female patients who underwent elective laparoscopic gynecological surgery, due to not meeting inclusion criteria or refusing to participate, 116 patients were included in this study, with 58 patients in each group. Due to CO\u003csub\u003e2 \u003c/sub\u003epneumoderma or changes in surgical methods, 55 cases in each group were finally analysed (Fig. 1). The general conditions of the patients are shown in Table 1.\u003c/p\u003e\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:150%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e\u0026nbsp; Table 1 Baseline Characteristics\u003c/span\u003e\u003c/p\u003e\n\u003ctable style=\"width:425.25pt;border-collapse:collapse;border:none;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: 1pt solid windowtext;border-right: 1pt solid windowtext;border-bottom: 1pt solid windowtext;border-image: initial;border-left: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eGroup P (n=55)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 132.1pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eGroup S (n=55)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57.4pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eP\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eAge(y)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e40.53\u0026plusmn;11.08\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e41.15\u0026plusmn;10.26\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.762\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eHeight(cm)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:-8.65pt;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e161.18\u0026plusmn;4.20\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e159.79\u0026plusmn;4.50\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.097\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eWeight(kg)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e59\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e54.5\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e63\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e56\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e51.9\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e60\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.057\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eBMI(kg/m2)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e22.74\u0026plusmn;2.28\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e22.31\u0026plusmn;2.15\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.262\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eSurgery duration(h)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e2.33\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e2.12\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e2.75\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e2.5\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e2.22\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e2.75\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.165\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eTotal blood loss(ml)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e100\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e50\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e120\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e80\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e50\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e100\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.424\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eUrine volume\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003eml\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e400\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e300\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e500\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e400\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e400\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e500\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.088\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-bottom: none;border-left: none;border-image: initial;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eFluid volume(ml)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e1200\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e1100\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e1500\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e1200(1100,1500\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border: none;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.645\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 128.95pt;border-top: none;border-left: none;border-bottom: 1pt solid windowtext;border-right: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eAirway pressure\u003c/span\u003e\u003c/p\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e(mmHg)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.8pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e15\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e13\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e16\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 111.4pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e15\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003e13\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e，\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e16\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 78.1pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 22.7pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.754\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eThe quantitative data with a normal distribution were expressed as mean \u0026plusmn; standard deviation\u003c/span\u003e\u003c/p\u003e\n\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eThe quantitative data with a non-normal distribution were expressed as median (interquartile range,IQR)\u003c/span\u003e\u003c/p\u003e\n\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eBMI Body mass index\u003c/span\u003e\u003c/p\u003e\u003cbr\u003e\u003cp\u003eThe comparison of the ONSD at each time point between the two groups is shown in Table 2 and Fig. 2. No significant difference in the baseline preoperative ONSD was found between the two groups. After anesthesia induction, the ONSD values all decreased compared to the baseline value in both two groups, but no significant differences between the two groups. At three time points (T\u003csub\u003eawake\u003c/sub\u003e, T\u003csub\u003einduction\u003c/sub\u003e, and T\u003csub\u003e0\u003c/sub\u003e), the ONSD was not significantly different between the two groups (p = 0.984, 0.666, and 0.646, respectively). Over time, at three time points (T\u003csub\u003e15\u003c/sub\u003e, T\u003csub\u003e30\u003c/sub\u003e, and T\u003csub\u003e45\u003c/sub\u003e), significant differences in ONSD were identified between the two groups (p= 0.031, 0.035, and 0.028, respectively). At T\u003csub\u003e1 h\u003c/sub\u003e, T\u003csub\u003e2 h\u003c/sub\u003e, T\u003csub\u003eend\u003c/sub\u003e, and T\u003csub\u003epacu\u003c/sub\u003e, no significant differences in ONSD were found between the two groups after statistical correction (p = 0.065, 0.211, 0.368, and 0.646 respectively).\u003c/p\u003e\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:150%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eTable 2 Comparison of ONSD at different time points between two groups.\u003c/span\u003e\u003c/p\u003e\n\u003ctable style=\"border-collapse:collapse;border:none;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 19.3pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 19.3pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eGroup P (n=55)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 92.1pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 19.3pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eGroup S (n=55)\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80.2pt;border-top: 1pt solid windowtext;border-left: none;border-bottom: 1pt solid windowtext;border-right: none;padding: 0in 5.4pt;height: 19.3pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eP\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;border: none;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003eawake\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;border: none;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.39\u0026plusmn;0.37\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;border: none;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.36\u0026plusmn;0.45\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;border: none;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.694\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003eInduction\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.06\u0026plusmn;0.45\u003csup\u003e*\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.05\u0026plusmn;0.45\u003csup\u003e*\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.882\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003e0\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.53\u0026plusmn;0.47\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.35\u0026plusmn;0.40\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.058\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003e15\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.64\u0026plusmn;0.48\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.50\u0026plusmn;0.29\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.031\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003e30\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.77\u0026plusmn;0.45\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.62\u0026plusmn;0.28\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.036\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T45\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.84\u0026plusmn;0.46\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.65\u0026plusmn;0.30\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.012\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003e1h\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.83\u0026plusmn;0.43\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.66\u0026plusmn;0.28\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.066\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003e2h\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.82\u0026plusmn;0.41\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.71\u0026plusmn;0.28\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.089\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003eend\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.84\u0026plusmn;0.44\u003csup\u003e*#\u0026nbsp;\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.71\u0026plusmn;0.34\u003csup\u003e*#\u003c/sup\u003e\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.082\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 147.15pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eONSD T\u003csub\u003ePACU\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e（\u003c/span\u003e\u003cspan style='font-family: \"Calibri\",sans-serif;'\u003emm\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e）\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 106.35pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.40\u0026plusmn;0.38\u003csup\u003e*#\u003c/sup\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85.05pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e4.36\u0026plusmn;0.35\u003csup\u003e*#\u003c/sup\u003e\u0026nbsp;\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 87.25pt;border-top: none;border-right: none;border-left: none;border-image: initial;border-bottom: 1pt solid windowtext;padding: 0in 5.4pt;height: 28.35pt;vertical-align: top;\"\u003e\n \u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;text-align:center;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.641\u003c/span\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp style='margin-top:0in;margin-right:0in;margin-bottom:8.0pt;margin-left:0in;line-height:107%;font-size:16px;font-family:\"Times New Roman\",serif;'\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eValues were expressed as the mean \u0026plusmn; standard variation. * meant comparison of ONSD intra group at each time points to T\u003csub\u003eawake.\u003c/sub\u003e In Group P, values of p were 0.000 except comparison of T\u003csub\u003epacu\u003c/sub\u003e to T\u003csub\u003eawake\u003c/sub\u003e which p value was 0.945; in Group S, values of p were 0.939\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e、\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003e0.035 and 0.884 when compared T\u003csub\u003e0\u003c/sub\u003e\u003c/span\u003e\u003cspan style=\"font-family:SimSun;\"\u003e、\u003c/span\u003e\u003cspan style='font-family:\"Calibri\",sans-serif;'\u003eT\u003csub\u003e15\u003c/sub\u003e and T\u003csub\u003epacu\u003c/sub\u003e to T\u003csub\u003eawake\u003c/sub\u003e, while p values were 0.000 at any other time points.# meant comparison of ONSD intra group at each time points to T\u003csub\u003einduction\u003c/sub\u003e ,and all p values were 0.000 in both two groups.\u003c/span\u003e\u003c/p\u003e\u003cbr\u003e\u003cp\u003eThe comparison of the MAP and BIS at each time point between the two groups is shown in Fig.3 and Fig.4.There are no significant differences in MAP and BIS at each time point between Group P and Group S. No hypotension or serious neurological complications such as cerebral haemorrhage or cerebral oedema occurred in either group.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study compared the effects of two general anesthesia drugs (propofol and sevoflurane) on the ONSD in patients undergoing laparoscopic gynecological surgery. The results showed that the ONSD was significantly reduced compared to the baseline value in the patients in the two groups after anesthesia induction and endotracheal intubation. With establishment of the CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and the Trendelenburg position, the ONSD in both groups increased and exceeded the baseline value. However, at first 45 minutes, the amplitude of the increase in the propofol group was greater than that in the sevoflurane group. Over time, considering the pneumoperitoneum and the Trendelenburg position, no significant difference in the ONSD was found between the two groups from 1 hour after starting the surgery to extubation at the end of the surgery. When leaving the recovery room, the ONSD returned to baseline in the patients in both groups.\u003c/p\u003e\n\u003cp\u003eIn this study, both groups received propofol and sufentanil for anesthesia induction, and cisatracurium was used for endotracheal intubation. Both sufentanil and propofol contract cerebral vessels and reduce the cerebral metabolic rate [9,10, 23]; therefore, the ONSD after anesthesia induction was reduced compared to the baseline value.\u003c/p\u003e\n\u003cp\u003eWith establishment of the CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and the Trendelenburg position, the ONSD increased gradually but recovered to baseline by 1 hour after surgery. The reason may be that the effect of the CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and body position on intracranial pressure exceeds the effect of drugs on intracranial blood flow. Bilateral internal cervical vessels and vertebral vessels play an important role in cerebral circulation [24]. After establishment of the CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and the Trendelenburg position, recirculation in the internal jugular vein and vertebral vein was obstructed. At the same time, the mean arterial pressure during establishment of the pneumoperitoneum and positioning was elevated compared to that after anesthesia induction. Whiteley et al. found that the ONSD was positively correlated with the mean arterial pressure [25].\u003c/p\u003e\n\u003cp\u003eFor the propofol group, our results are basically consistent with those of Blecha et al. [26]; however, the amplitude of changes in the optic nerve sheath was higher than that in the study of Blecha et al., and maybe the reason for the difference is that the patients in the study of Blecha et al. received midazolam before surgery, which can reduce intracranial pressure. In addition, the patients in that study were from western countries, and the ONSD varied among different races. Wang et al. found that among the Chinese population, the predicted cut-off value of ONSD that means intracranial pressure higher than 20 cmH\u003csub\u003e2\u003c/sub\u003eO was lower than that in Caucasians [27].\u003c/p\u003e\n\u003cp\u003eThe effects of CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and Trendelenburg position establishment on the ONSD in sevoflurane versus propofol anesthesia are different in various studies. We found that although the ONSD increased in the sevoflurane group, the amplitude of the increase was smaller than that in the propofol group at the early stage of surgery. In the study of Robba et al. [22], the amplitude of the increase in the ONSD after sevoflurane anesthesia was consistent with that in our study. However, the studies of Kim et al. [28] and Chin et al. [29] showed that the amplitude of the increase in the ONSD after sevoflurane anesthesia was higher than that in our study. Verdonck et al. [7] believed that the ONSD remains unchanged in patients undergoing sevoflurane anesthesia.\u003c/p\u003e\n\u003cp\u003eThe results of this study are generally consistent with those of Lee et al [30], while in the first 30 minutes of operation,the results were inconsistent. The main reason may be that Lee et al. used midazolam and glinbromide before operation; on the other hand, study of Lee et al only maintained BIS at 40-60 during the whole operation, but did not compare the BIS values between the two groups. The depth of anesthesia may affect the changes of cerebral blood flow, thus further affecting the changes of intracranial pressure and ONSD value.\u003c/p\u003e\n\u003cp\u003eThe inconsistencies across different studies may be due to the lack of consistency in patients\u0026rsquo; anesthetic depth and sevoflurane blood concentration. Sevoflurane has a dominant effect on cerebral oxygen metabolism at a low concentration; while at medium and high concentrations, it has a direct vasodilatory effect [31]. Propofol reduces cerebral blood flow more because of its effect on reducing cerebral oxygen metabolism rather than direct vasoconstriction [32,33]. Meanwhile, the ONSD can reflect intracranial pressure in real time; however, the correlation coefficient between ONSD and intracranial pressure in previous studies was 0.660-0.820 [19,34,35]. Hansen et al. believed that the ONSD and intracranial pressure have an elastic nonlinear relationship [17]. In other words, the ONSD may better reflect changing trends in intracranial pressure than specific values.\u003c/p\u003e\n\u003cp\u003eWe found that although the ONSD increased significantly in both groups, it returned to baseline 1 hour after surgery. Animal studies suggest that with establishment of the CO\u003csub\u003e2\u003c/sub\u003e pneumoperitoneum and the Trendelenburg position, intracranial pressure increased by 10 mmHg compared to the baseline value [36]. However, Kalmar et al. [37] believe that intracranial pressure fluctuations within the physiological range are regulated by multiple mechanisms，and that the intracranial pressure increases exponentially only when these regulatory mechanisms are exhausted. Notably, the brain has a strong ability to transfer CSF to the vascular system, and when intracranial pressure increased, CSF moved intrathecally at a rate of 2 ml/min [38，39], which is also why the ONSD returned to baseline 1 hour after surgery. On the other way, a reduction of the intracranial blood volume after termination of the steep Trendelenburg position could be the reason.\u003c/p\u003e\n\u003cp\u003eFour limitations exist in this study. First, this study did not analyse changes in the ONSD in patients with longer operative times (\u0026gt;3 hours), mainly because few cases required long operative times (\u0026gt;3 hours) in this study. Hansen et al. suggested that prolonged intracranial hypertension affected the reversibility of optic nerve sheath changes [17]. Therefore, we hypothesized that the duration of the increase in ONSD in patients undergoing prolonged laparoscopic gynecological surgery would be prolonged, but further studies are needed for confirmation. Second，all the patients included in this study were female patients younger than 65 years old, and further studies are needed to determine whether similar conclusions can be established for male or elderly patients.\u003c/p\u003e\n\u003cp\u003eThird, in our study, sevoflurane was maintained at 1\u0026ndash;1.5 minimal alveolar concentration (MAC) while we do not record values of end-tidal concentrations of sevoflurane (Etsevo). Animal studies suggest that cerebral blood flow may not be changed when Etsevo is 0.3-1.5MAC[40]. Artru et al find ICP is not changed when sevoflurane is 0.5MAC、1.0MAC or 1.5MAC in neurosurgery patients[41].We guess that small changes in Etsevo during 0.5-1.5MAC may not have significant effects on cerebral blood flow .Fourth, Whiteley et al suggest that ONSD is positively correlated with MAP[25].In our study ,there are no significant differences between Group S and Group P at different time points and that is why we ignore the effect of blood pressure on ONSD.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn conclusion, we found that when comparing the two drugs, at the early stage, the ONSD post-pneumoperitoneum in the propofol group was slightly larger than that in the sevoflurane group, and the difference was statistically significant. No significant difference was observed between the two groups 1 hour after surgery.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eoptic nerve sheath diameter ONSD;American Society of Anaesthesiologists \u0026nbsp;ASA;mean arterial pressure MAP; Bispectral index BIS;minimal alveolar concentration\u0026nbsp; MAC; post-anesthetic recovery room PACU.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u0026nbsp; After approval by the ethics committee of Obstetrics and Gynaecology Hospital of Fudan University. The committee\u0026rsquo;s reference number is 2018-05.We herein confirm written consent obtained from each patient in accordance with the Declaration of Helsinki in order to report and publish the individual patient data obtained. A written consent to participate from each patient in the current study was obtained.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication \u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials \u003c/strong\u003eThe trial protocol, datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests \u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding \u003c/strong\u003e\u0026nbsp;Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors' contributions\u003c/strong\u003e WG, first author: Study Design, data collection, interpretation, drafting article, critical revision of the article and final approval of the version to be published.\u003c/p\u003e\n\u003cp\u003eCC, co-first author: Study Design, references review, data analysis, drafting article, critical revision of the article and final approval of the version to be published.\u003c/p\u003e\n\u003cp\u003eXS, second author: Study Design, critical revision of the article and final approval of the version to be published.\u003c/p\u003e\n\u003cp\u003eSH，correspondance author: Study Design, data analysis, critical revision of the article and final approval of the version to be published.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements \u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; informations \u003c/strong\u003e\u0026nbsp;Weilian Geng , [email protected], Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China\u2028;Changxing Chen, [email protected], Emergency and Critical Care Department, Shanghai General Hospital, Shanghai, ChinaXingfeng Sun, [email protected], Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China\u2028;Shaoqiang Huang, \u003ca href=\"mailto:[email protected]\"\[email protected]\u003c/a\u003e, Department of Anesthesia, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China\u2028\u003c/p\u003e"},{"header":"References","content":"\u003cp\u003e[1] Fahy BG, Barnas GM, Nagle SE, Flowers JL, Njoku MJ, Agarwal M. Effects of Trendelenburg and reverse Trendelenburg postures on lung and chest wall mechanics. J Clin Anesth 1996;8(3): 236\u0026ndash;44. http://doi.org/\u003ca href=\"https://doi.org/10.1016/0952-8180(96)00017-7\"\u003e10.1016/0952-8180(96)00017-7\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[2] Halverson A, Buchanan R, Jacobs L, et al. Evaluation of mechanism of increased intracranial pressure with \u2028insufflation. Surg Endosc 1998; 12: 266-9. http://doi.org/\u003ca href=\"https://doi.org/10.1007/s004649900648\"\u003e10.1007/s004649900648\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[3] Lassen NA, Christensen MS. Physiology of cerebral blood flow. Br J Anaesth 1976;48(8):719\u0026ndash;34. http://doi.org/\u003ca href=\"https://doi.org/10.1093/bja/48.8.719\"\u003e10.1093/bja/48.8.719\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[4] \u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Pandey+R\u0026amp;cauthor_id=21268573\"\u003eR Pandey\u003c/a\u003e,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Garg+R\u0026amp;cauthor_id=21268573\"\u003eR Garg\u003c/a\u003e,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Darlong+V\u0026amp;cauthor_id=21268573\"\u003eV Darlong\u003c/a\u003e,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Punj+J\u0026amp;cauthor_id=21268573\"\u003eJ Punj\u003c/a\u003e,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Chandralekha\u0026amp;cauthor_id=21268573\"\u003eChandralekha\u003c/a\u003e,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Kumar+A\u0026amp;cauthor_id=21268573\"\u003eA Kumar\u003c/a\u003e. Unpredicted neurological complications after robotic laparoscopic radical cystectomy and ileal conduit formation in steep trendelenburg position: two case reports. Acta Anaesthesiol Belg 2010; 61: 163\u0026ndash;6. PMID: 21268573\u003c/p\u003e\n\u003cp\u003e[5] Cooke SJ, Paterson-Brown S. Association between laparoscopic abdominal surgery and postoperative symptoms of raised intracranial pressure. Surg Endosc 2001; 15: 723\u0026ndash;5. \u2028 http://doi.org/10.1007/s00464-001-0004-8.\u003c/p\u003e\n\u003cp\u003e[6] \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Kim%20SH%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=26257848\"\u003eKim SH\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Kim%20HJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=26257848\"\u003eKim HJ\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Jung%20KT%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=26257848\"\u003eJung KT\u003c/a\u003e. Position does not affect the optic nerve sheath diameter during laparoscopy. Korean J Anesthesiol 2015;68(4):358-63. DOI:\u003ca href=\"https://doi.org/10.4097/kjae.2015.68.4.358\"\u003ehttps://doi.org/10.4097/kjae.2015.68.4.358\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[7] Verdonck P, Kalmar AF, Suy K, et al. Optic nerve sheath diameter remains constant during robot \u2028assisted laparoscopic radical prostatectomy. PLoS One 2014; 9: e111916. http://doi.org/ 10.1371/journal.pone.0111916.\u003c/p\u003e\n\u003cp\u003e[8] Conti A, Iacopino DG, Fodale V, Micalizzi S, Penna O, Santamaria LB. Cerebral haemodynamic changes during propofol-remifentanil or sevoflurane anesthesia: transcranial Doppler study under Bispectral Index Monitoring. Br J Anaesth 2006; 97(3):333-9. http://doi.org/\u003ca href=\"https://doi.org/10.1093/bja/ael169\"\u003e10.1093/bja/ael169\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[9] Oshima T, Karasawa F, Satoh T. Effects of propofol on cerebral blood flow and the metabolic rate of oxygen in humans. Acta Anaesthesiol Scand 2002:46:831\u0026ndash;5. http://doi.org/10.1034/j.1399-6576.2002.460713.x\u003c/p\u003e\n\u003cp\u003e[10] Doyle PW, Matta BF. Burst suppression or isoelectric encephalogram for cerebral protection: Evidence from metabolic suppression studies. Br J Anaesth 1999; 83:580\u0026ndash;4. http://doi.org/10.1093/bja/83.4.580.\u003c/p\u003e\n\u003cp\u003e[11]Eng C, Lam AM, Mayberg TS, \u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Lee+C\u0026amp;cauthor_id=1443739\"\u003eLee\u003c/a\u003e C,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Mathisen+T\u0026amp;cauthor_id=1443739\"\u003eMathisen\u003c/a\u003e T.The influence of propofol with and without nitrous oxide on cerebral blood flow velocity and CO, reactivity in humans. Anesthesiology 1992; 77:872-9. http://doi.org/\u003ca href=\"https://doi.org/10.1097/00000542-199211000-00006\"\u003e10.1097/00000542-199211000-00006\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[12]Matta BF, Lam AM, Strebel S, Mayberg TS. Cerebral pressure autoregulation and CO-reactivity during propofol-induced EEG suppression. Br J Anaesth 1995; 74:159-63. http://doi.org/10.1093/bja/74.2.159\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;[13]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Drummond%20JC%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=3777475\"\u003eDrummond JC\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Todd%20MM%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=3777475\"\u003eTodd MM\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Scheller%20MS%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=3777475\"\u003eScheller MS\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Shapiro%20HM%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=3777475\"\u003eShapiro HM\u003c/a\u003e. A comparison of the direct cerebral vasodilating potencies of halothane and isoflurane in the New Zealand white rabbit. Anesthesiology 1986; 65(5): 462-7. http://doi.org/ 10.1097/00000542-198611000-00002\u003c/p\u003e\n\u003cp\u003e[14] Gupta S, Heath K, Matta BF. Effect of incremental doses of sevoflurane on cerebral pressure autoregulation in humans. Br J Anaesth 1997; 79: 469\u0026ndash;72. http://doi.org/10.1093/bja/79.4.469 \u2028\u003c/p\u003e\n\u003cp\u003e[15]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Choi%20SH%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=19032299\"\u003eChoi SH\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Lee%20SJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=19032299\"\u003eLee SJ\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Rha%20KH%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=19032299\"\u003eRha KH\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Shin%20SK%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=19032299\"\u003eShin SK\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Oh%20YJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=19032299\"\u003eOh YJ\u003c/a\u003e.The effect of pneumoperitoneum and Trendelenburg position on acute cerebral blood flow\u0026ndash;carbon dioxide reactivity under sevoflurane anesthesia. Anesthesia. 2008; 63(12): 1314-8. http://doi.org/10.1111/j.1365-2044.2008.05636.x\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[16] Killer HE,\u0026nbsp;Laeng HR,\u0026nbsp;Flammer J,\u0026nbsp;\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Groscurth+P\u0026amp;cauthor_id=12770980\"\u003eGroscurth\u003c/a\u003e P.Architecture of arachnoid trabeculae, pillars,and septa in the subarachnoid space of the human optic nerve:anatomy and clinical considerations. Br J Ophthalmol 2003;87(6):777-81. http://doi.org/10.1136/bjo.87.6.777\u003c/p\u003e\n\u003cp\u003e[17]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Hansen%20HC%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=21518306\"\u003eHansen HC\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Lagr%C3%A8ze%20W%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=21518306\"\u003eLagr\u0026egrave;ze W\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Krueger%20O%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=21518306\"\u003eKrueger O\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Helmke%20K%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=21518306\"\u003eHelmke K\u003c/a\u003e.Dependence of the optic nerve sheath diameter on acutely applied subarachnoidal pressure\u0026ndash;an experimental ultrasound study. Acta Ophthalmol 2011;89(6):528-32. http://doi.org/10.1111/j.1755-3768.2011.02159.x\u003c/p\u003e\n\u003cp\u003e[18] Maissan IM, Dirven PJ, Haitsma IK, \u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Hoeks+SE\u0026amp;cauthor_id=25955869\"\u003eHoeks\u003c/a\u003e\u0026nbsp;SE, \u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Gommers+D\u0026amp;cauthor_id=25955869\"\u003eGommers\u003c/a\u003e D,\u003ca href=\"https://pubmed.ncbi.nlm.nih.gov/?term=Stolker+RJ\u0026amp;cauthor_id=25955869\"\u003e Stolker\u003c/a\u003e RJ. Ultrasonographic measured optic nerve sheath diameter as an accurate and quick monitor for changes in intracranial pressure. J Neurosurg 2015;123(3):743-7. http://doi.org/ 10.3171/2014.10.JNS141197\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;[19]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Wang%20LJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28169341\"\u003eWang LJ\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Yao%20Y%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28169341\"\u003eYao Y\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Feng%20LS%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28169341\"\u003eFeng LS\u003c/a\u003e, et al. Noninvasive and quantitative intracranial pressure estimation using ultrasonographic measurement of optic nerve sheath diameter. Sci Rep 2017;7(2):42063. http://doi.org/10.1038/srep42063\u003c/p\u003e\n\u003cp\u003e[20] Lochner P,Coppo L,Cantello R,\u0026nbsp;et al. Intra- and interobserver reliability of transorbital sonographic assessment of the\u0026nbsp;optic nerve\u0026nbsp;sheathdiameter\u0026nbsp;and\u0026nbsp;optic nerve\u0026nbsp;diameter\u0026nbsp;in healthy adults. J Ultrasound 2014;19(1):41-5. http://doi.org/10.1007/s40477-014-0144-z\u003c/p\u003e\n\u003cp\u003e[21] Hassen GW, Bruck I, Donahue J, et al.Accuracy of optic nerve sheath diameter measurement by emergency physicians using bedside ultrasound. J Emerg Med 2015,48(4):450-457. http://doi.org/10.1016/j.jemermed.2014.09.060\u003c/p\u003e\n\u003cp\u003e[22]Robba C, Cardim D, Donnelly J, et al.\u2028Effects of pneumoperitoneum and Trendelenburg position on intracranial pressure assessed using different non-invasive methods. Br J Anaesth 2016;117 (6): 783-9. http://doi.org/10.1093/bja/aew356\u003c/p\u003e\n\u003cp\u003e[23] Werner C, Hoffman WE, Baughman VL, Albrecht RF, Schulte J. Effects of sufentanil on cerebral blood flow, cerebral blood flow velocity, and metabolism in dogs. Anesth Analg 1991; 72: 177-81. http://doi.org/10.1213/00000539-199102000-00006\u003c/p\u003e\n\u003cp\u003e[24]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Smith%20KJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=22926137\"\u003eSmith KJ\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Wong%20LE%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=22926137\"\u003eWong LE\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Eves%20ND%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=22926137\"\u003eEves ND\u003c/a\u003e, et al. Regional cerebral blood flow distribution during exercise: influence of oxygen. Respir Physiol Neurobiol 2012;184(1):97-105. http://doi.org/10.1016/j.resp.2012.07.014\u003c/p\u003e\n\u003cp\u003e[25] Whiteley JR, Taylor J, Henry M, Epperson TI, Hand WR. Detection of elevated intracranial pressure in robot-assisted laparoscopic radical prostatectomy using ultrasonography of optic nerve sheath diameter. J Neurosurg Anesthesiol 2015;27(2):155\u0026ndash;9. http://doi.org/10.1097/ANA.0000000000000106\u0026nbsp; \u2028\u003c/p\u003e\n\u003cp\u003e[26]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Blecha%20S%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28284189\"\u003eBlecha S\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Harth%20M%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28284189\"\u003eHarth M\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Schlachetzki%20F%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=28284189\"\u003eSchlachetzki F\u003c/a\u003e, et al. Changes in intraocular pressure and optic nerve sheath diameter in patients undergoing robotic-assisted laparoscopic prostatectomy in steep 45\u0026deg; Trendelenburg position.BMC Anesthesiol 2017;11;17(1):40. http://doi.org/10.1186/s12871-017-0333-3\u003c/p\u003e\n\u003cp\u003e[27] Wang L,Feng L,Yao Y, et al. Optimal optic nerve sheath diameter threshold for the\u0026nbsp;identification\u0026nbsp;of\u0026nbsp;elevated\u0026nbsp;openingpressure\u0026nbsp;on\u0026nbsp;lumbarpuncture\u0026nbsp;in a\u0026nbsp;Chinese\u0026nbsp;population. PLoS One,\u0026nbsp;2015,10(2):e0117939. http://doi.org/10.1371/journal.pone.0117939\u003c/p\u003e\n\u003cp\u003e[28] Kim MS, Bai SJ, Lee JR, Choi YD, Kim YJ, Choi SH. Increase in intracranial pressure during carbon dioxide pneumoperitoneum with steep trendelenburg positioning proven by ultrasonographic measurement of optic nerve sheath diameter. J Endourol 2014;28(7):801\u0026ndash;6. http://doi.org/10.1089/end.2014.0019\u0026nbsp; \u2028\u003c/p\u003e\n\u003cp\u003e[29] Chin JH, Seo H, Lee EH, et al. Sonographic optic nerve sheath diameter as a surrogate measure for intracranial pressure in anesthetized patients in the Trendelenburg position. BMC Anesthesiol 2015;15:43. \u003ca href=\"http://doi.org/10.1186/s12871-015-0025-9\"\u003ehttp://doi.org/10.1186/s12871-015-0025-9\u003c/a\u003e\u003c/p\u003e\n\u003cp\u003e[30]Lee YY et al. Optic nerve sheath diameter changes during gynecologic surgery in the Trendelenburg position: comparison of propofol-based total intravenous anesthesia and sevoflurane anesthesia. Anesth Pain Med 2019;14:393-400\u003c/p\u003e\n\u003cp\u003e[31]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Doe%20A%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27565964\"\u003eDoe A\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Kumagai%20M%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27565964\"\u003eKumagai M\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Tamura%20Y%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27565964\"\u003eTamura Y\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Sakai%20A%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27565964\"\u003eSakai A\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Suzuki%20K%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27565964\"\u003eSuzuki K\u003c/a\u003e. A comparative analysis of the effects of sevoflurane and propofol on cerebral oxygenation during steep Trendelenburg position and pneumoperitoneum for robotic-assisted laparoscopic prostatectomy. J Anesth 2016 ;30(6):949-55. http://doi.org/10.1007/s00540-016-2241-y\u003c/p\u003e\n\u003cp\u003e[32]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Holzer%20A%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=12603451\"\u003eHolzer A\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Winter%20W%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=12603451\"\u003eWinter W\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Greher%20M%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=12603451\"\u003eGreher M\u003c/a\u003e, et al. A comparison of propofol and sevoflurane anesthesia: effects on aortic blood flow velocity and middle cerebral artery blood flow velocity. Anesthesia 2003;58(3):217-22. http://doi.org/10.1046/j.1365-2044.2003.03041.x\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[33]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Laaksonen%20L%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=29935583\"\u003eLaaksonen L\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Kallioinen%20M%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=29935583\"\u003eKallioinen M\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=L%C3%A5ngsj%C3%B6%20J%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=29935583\"\u003eL\u0026aring;ngsj\u0026ouml; J\u003c/a\u003e, et al. Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study. Br J Anaesth 2018;121(1):281-90. http://doi.org/\u003ca href=\"https://doi.org/10.1016/j.bja.2018.04.008\"\u003e10.1016/j.bja.2018.04.008\u003c/a\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[34]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Raffiz%20M%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27852525\"\u003eRaffiz M\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Abdullah%20JM%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27852525\"\u003eAbdullah JM\u003c/a\u003e. Optic nerve sheath diameter measurement: a means of detecting raised ICP in adult traumatic and non-traumatic neurosurgical patients. Am J Emerg Med 2017 ;35(1):150-3. http://doi.org/10.1016/j.ajem.2016.09.044\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[35]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Padayachy%20LC%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27659819\"\u003ePadayachy LC\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Padayachy%20V%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27659819\"\u003ePadayachy V\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Galal%20U%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27659819\"\u003eGalal U\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Gray%20R%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27659819\"\u003eGray R\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Fieggen%20AG%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=27659819\"\u003eFieggen AG\u003c/a\u003e. \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/27659819\"\u003eThe relationship between transorbital ultrasound measurement of the optic nerve sheath diameter (ONSD) and invasively measured ICP in children: Part I: repeatability, observer variability and general analysis.\u003c/a\u003e Childs Nerv Syst 2016;32(10):1769-78. http://doi.org/10.1007/s00381-016-3067-5\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[36] Tatebayashi K, Asai Y, Maeda T, Shiraishi Y, Miyoshi M, Kawai Y. Effects of head-down tilt on the intracranial pressure in conscious rabbits. Brain Res 2003;977(1):55-61. http://doi.org/10.1016/s0006-8993(03)02723-9\u003c/p\u003e\n\u003cp\u003e[37] Kalmar AF, Dewaele F, Foubert L, et al. Cerebral haemodynamic physiology during steep Trendelenburg position and CO(2) pneumoperitoneum. Br J Anaesth 2012;108(3):478-84. http://doi.org/10.1093/bja/aer448\u003c/p\u003e\n\u003cp\u003e[38] Eklund A, Smielewski P, Chambers I, et al. Assessment of cerebrospinal fluid outflow resistance. Med Biol Eng Comput 2007; 45(8): 719-35. http://doi.org/ 10.1007/s11517-007-0199-5\u003c/p\u003e\n\u003cp\u003e[39]Kalmar AF, De Ley G, Van Den Broecke C, Van Aken J, Struys MM, et al. Influence of an increased intracranial pressure on cerebral and systemic haemodynamics during endoscopic neurosurgery: an animal model. Br J Anaesth. 2009 Mar;102(3):361-8.\u003c/p\u003e\n\u003cp\u003e[40]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Kimme%20P%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=17430324\"\u003eKimme P\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Ledin%20T%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=17430324\"\u003eLedin T\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Sj%C3%B6berg%20F%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=17430324\"\u003eSj\u0026ouml;berg F\u003c/a\u003e. Dose effect of sevoflurane and isoflurane anesthetics on cortical blood flow during controlled hypotension in the pig. Acta Anaesthesiol Scand. 2007 May;51(5):607-13.\u003c/p\u003e\n\u003cp\u003e[41]\u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Artru%20AA%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=9296414\"\u003eArtru AA\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Lam%20AM%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=9296414\"\u003eLam AM\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Johnson%20JO%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=9296414\"\u003eJohnson JO\u003c/a\u003e, \u003ca href=\"https://www.ncbi.nlm.nih.gov/pubmed/?term=Sperry%20RJ%5BAuthor%5D\u0026amp;cauthor=true\u0026amp;cauthor_uid=9296414\"\u003eSperry RJ\u003c/a\u003e. Intracranial pressure, middle cerebral artery flow velocity, and plasma inorganic fluoride concentrations in neurosurgical patients receiving sevoflurane or isoflurane. Anesth Analg. 1997 Sep;85(3):587-92.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"optic nerve sheath diameter,ONSD ,sevoflurane, propofol, CO2 pneumoperitoneum, Trendelenburg position","lastPublishedDoi":"10.21203/rs.3.rs-52905/v3","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-52905/v3","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e The results of studies on changes in intracranial pressure in patients undergoing laparoscopic surgery are inconsistent. Meanwhile, previous neurosurgery studies have suggested that propofol and sevoflurane have inconsistent effects on cerebral blood flow and cerebrovascular self-regulation. The purpose of this study is to compare changes in the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery under anesthetic maintenance with propofol versus sevoflurane. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e This study included 110 patients undergoing laparoscopic gynecological surgery with an estimated operative time of more than 2 hours under general anesthesia. The study was a randomized controlled study. The optic nerve sheath diameter（ONSD）at various time points was measured by ultrasound, including when the patients entered the operating room (Tawake), after successful anesthesia induction and endotracheal intubation (Tinduction), when the body position was adjusted to the Trendelenburg position and the CO\u003csub\u003e2 \u003c/sub\u003epneumoperitoneum pressure reached 14 mmHg, which was recorded as T\u003csub\u003e0\u003c/sub\u003e. Then, measurements were conducted every 15 minutes for the first 1 hour and then once every hour until the end of the surgery（T\u003csub\u003e15\u003c/sub\u003e,T\u003csub\u003e30\u003c/sub\u003e,T\u003csub\u003e45\u003c/sub\u003e ,T\u003csub\u003e1h\u003c/sub\u003e ,T\u003csub\u003e2h\u003c/sub\u003e…）, after the end of surgery and the tracheal tube was removed (T\u003csub\u003eend\u003c/sub\u003e), and before the patients were transferred to the ward (T\u003csub\u003epacu\u003c/sub\u003e).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e A significant difference in optic nerve sheath diameter was found between two groups at T\u003csub\u003e15\u003c/sub\u003e, T\u003csub\u003e30\u003c/sub\u003e, T\u003csub\u003e45 \u003c/sub\u003e(4.64±0.48mm and 4.50±0.29mm, respectively, p=0.031;4.77±0.45mm and 4.62±0.28mm, respectively, p=0.036;4.84±0.46mm and 4.65±0.30mm, respectively, p=0.012), while there was no significant difference at T\u003csub\u003eawake\u003c/sub\u003e and other time points. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e During laparoscopic gynecological surgery lasting more than 2 hours, the optic nerve sheath diameter was slightly larger in the propofol group than that in the sevoflurane group in the first 45 minutes. No significant difference was observed between the two groups 1 hour after surgery. \u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTrial registration\u003c/strong\u003e clinicaltrials.gov，NCT03498235. Retrospectively registered 1 March2018,https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0007UMM\u0026amp;selectaction=Edit\u0026amp;uid=U00040C5\u0026amp;ts=39\u0026amp;cx=c7i8ic\u003c/p\u003e\u003cp\u003eThe manuscript adheres to CONSORT guidelines.\u003c/p\u003e","manuscriptTitle":"Effects of sevoflurane and propofol on the optic nerve sheath diameter in patients undergoing laparoscopic gynecological surgery: A Randomized controlled clinical studies","msid":"","msnumber":"","nonDraftVersions":[{"code":3,"date":"2021-01-15 11:36:38","doi":"10.21203/rs.3.rs-52905/v3","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accept","date":"2021-01-11T00:00:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-01-06T00:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2021-01-05T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2021-01-05T23:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":2,"date":"2020-12-08 14:55:36","doi":"10.21203/rs.3.rs-52905/v2","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Minor revision","date":"2021-01-04T00:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-12-31T00:00:00+00:00","index":2,"fulltext":"Recommendation: Accept without revision\nForm responses:\n---\n\nComments to Author:\n---\nI congratulate with the authors for this interesting paper. I think it's a very important topic for anesthesiologists because of the increasing utility of the ONSD measurement in clinical practice.* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons upon publication of the manuscript. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **Yes**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"editorInvitedReview","content":"","date":"2020-12-21T00:00:00+00:00","index":1,"fulltext":"Recommendation: Accept after minor essential revisions\nForm responses:\n---\n\nComments to Author:\n---\nGeng and colleagues presented the revised version of the manuscript about the prospective, monoinstitutional, randomized control trial with the aim to investigate the effect of anaesthetic drugs (propofol versus sevoflurane) on the changes in the optic nerve sheath diameter (ONSD) in patients undergoing laparoscopic gynecological surgery.\nThe previous highlighted issues were adequately addressed, improving the methodological value of the manuscript.\nOnly two minor issues regarding the applied changes should be further discussed:\n1) In the statistical analysis section, originally the authors esteemed the likelihood of withdrawal of approximately 15%. In the revised version, the authors reported 25%. The change is not clear as the protocol should not be subjected to changes at the completion of the study. A brief comment should be provided.\n2) The authors reported the following sentence for the description of the ONSD sonographic appearance: \"On the ultrasound screen, we can see a sharp low gyrus, which is perpendicular to the eyeball and surrounded by echogenic fat behind the ball, namely the optic nerve sheath\". I suggest the authors to rewrite the sentence for a better comprehension of the reader.\n* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons upon publication of the manuscript. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **Yes**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"reviewerAgreed","content":"","date":"2020-11-29T01:00:00+00:00","index":2,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2020-11-29T00:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-11-29T00:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2020-11-26T00:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-11-25T23:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-11-25T23:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}},{"code":1,"date":"2020-08-24 15:58:08","doi":"10.21203/rs.3.rs-52905/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2020-10-23T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2020-09-26T12:00:00+00:00","index":3,"fulltext":"Recommendation: Accept after minor essential revisions\nForm responses:\n---\n\nComments to Author:\n---\nThe manuscript is comparing ONSD during gynecological laparoscopic surgery under sevoflurane versus propofol anesthesia. In my opinion, it might be published following minor revisions, mostly related to language issues. The methods and statistical analysis were clearly described. The results were discussed appropriately. As the authors did not mention the changes in response to the previous reviewers comments in a detailed way, I could not evaluate whether all the comments were addressed or not. My comments can be seen below.\n\nAbstract:\n1. Methods section of abstract, Page 3, line 24: Please use the open form of ONSD with the abbreviation in parenthesis before using the abbreviation alone.\n2. Methods section of abstract, Page 3, line 34: '….every 15 minutes for first 1 hour' could be changed as '…every 15 minutes for the first hour'.\n3. Methods section of abstract, Page 3, line 38: '… after end of surgery and the tracheal tube was removed (Tend)..' should be changed as '..after the end of the surgery…'\n4. Results section of abstract, Page 3, lines 46-48: p values shown as the example 'p =0.036' should be corrected as 'p=0.036'\n5. Results section of abstract, Page 3, line 49: '.. while no significant…' should be changed as '…while there was no significant….'\n6. The authors mentioned some part of the results in results section and some other in conclusion section. Please re-configure the content of results and conclusion.\nBackground:\n7. Please correct all 'CO2' as 'CO2'\n8. Page 6, Line 32: 'The purpose of this study is to compare the effects of propofol and sevoflurane on ONSD which as a measure of intracranial pressure by ultrasound in patients….' Please consider the sentence again. ..which is/as a…?\nMethods:\n9. Page 7, line 1: Please correct '(BMI) \u003c18.5 kg/m2' as kg/m2 and apply similar corrections all over the text, if necessary.\n10. Page 7, line 46-49: I recommend to revise the sentence 'When the patient awake, the tidal volume was greater than 6 L/min, the respiratory rate was 14~20 breaths/min with no PEEP, and the endotracheal tube had been removed. After the endotracheal tube was removed, the patient was routinely monitored……' as 'When the patient was awake, the tidal volume was greater than 6 L/min, and the respiratory rate was 14~20 breaths/min with no PEEP; the endotracheal tube was removed. Afterwards, the patient was routinely monitored……'\n11. Please mention the model and the name of the ultrasound device properly.\n12. The authors mention that 55 patients in each group were needed with the likelihood of 15% withdrawal (the necessary calculated number was 48 patients in each group). So please explain the reason for starting with 120 patients instead of starting with 110 patients in the 'statistical analysis' part.\nResults:\n13. Please correct the punctuation in table/figure headers and descriptions.\nDiscussion:\n14. Page 14, line 46: Please correct '…end-tide…' as 'end-tidal'\n15. Please revise the conclusions in the abstract and the main text to be consistent with each other.\n* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons upon publication of the manuscript. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **Yes**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"editorInvitedReview","content":"","date":"2020-09-26T12:00:00+00:00","index":2,"fulltext":"Recommendation: Major revisions required\nForm responses:\n---\n\nComments to Author:\n---\nThe authors presented a prospective, monoinstitutional, randomized control trial with the aim to investigate the effect of anaesthetic drugs (propofol versus sevoflurane) on the changes in the optic nerve sheath diameter (ONSD) in patients undergoing laparoscopic gynecological surgery.\nAccording to eligibility criteria, 120 patients were enrolled, 116 were randomized by a computerized random selection and 110 were analysed (55 in each group). Sonographical ONSD measurements were obtained at the entrance of the patient in the OR, after anesthesia induction and endotracheal intubation, when the body position was adjusted to the Trendelenburg position and the CO2 pneumoperitoneum pressure reached 14 mmHg and every 15 minutes for 1 hour followed by every hour until the end of the surgery (Tawake, Tinduction, T0, T15, T30, T45, T1h, T2h, Tend and Tpauc). Also the mean arterial pressure (MAP) and the Bispectral index (BIS) were recorded at every time point.\nThe results showed a significant ONSD enlargement at T15, T30 and T45 in the sevoflurane group compared to the propofol group. No other significant differences were observed in the ONSD measurement, MAP or BIS at each time points between two groups.\nThe authors reported a RCT comparing the effect on the ONSD induced by different anaesthetic drugs. This topic is still debated in the current literature and discording results failed to show a clear relationship. Therefore, the effort of the authors to shed some lights about this issue should be praised.\nHowever, some concerns are present and need to be clarified:\n\n1) The primary outcome should be specified more clearly in the method section.\n2) The randomization procedure should be discussed in more details. Was intentionally adopted the 1:1 ratio? Did the authors used a block/stratification randomization method? What about the allocation concealment strategy?\n3) The authors in the Material and method section, regarding the ONSD measurements method, reported \"The ONSD was measured at 3 mm behind the transverse diameter of the bilateral eyeballs\". This sentence is not clear and should therefore modified as the methodology of the ONSD measurements is crucial to obtain reliable data.\n4) The authors in the Material and Method section (page 8) reported \"The high-frequency ultrasonic probe…\". The frequency of the utilized probe should be reported.\n5) An important data, the angle of the Trendelenburg position adopted in the OR, are not reported. This information is crucial as the Trendelenburg angle is correlated to the cerebral venous drainage and the shift of the CSF from the spinal compartment to the cranial compartment and should be reported.\n6) A previous article investigated the relationship between the effects of propofol and sevoflurane on the ONSD changes in laparoscopic gynecological surgery (Lee YY et al. Optic nerve sheath diameter changes during gynecologic surgery in the Trendelenburg position: comparison of propofol-based total intravenous anesthesia and sevoflurane anesthesia. Anesth Pain Med 2019;14:393-400). The previous literature about the same topic should be cited and discussed in the appropriate section.\n7) A careful proofreading of the English language should be provided.\n* Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons upon publication of the manuscript. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests' below**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **No**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"editorInvitedReview","content":"","date":"2020-09-18T12:00:00+00:00","index":1,"fulltext":"Recommendation: Accept without revision\nForm responses:\n---\n\nComments to Author:\n---\nI have been given the opportunity to review the first revision. It is a modest study with modest goals. The limitations the authors make note of in their discussion - namely, the young age of the study subjects and the relatively short duration of surgery - are valid, and make it difficult to extrapolate their conclusions much further. But the study itself is clearly thought out and appropriately executed. * Publons Reviewer Recognition. Springer Nature can send verification of this review directly to Publons (a subsidiary of Clarivate Analytics). If you would like to take advantage of this service, please click on the “Yes” option below. Your name, email address, title of the reviewed manuscript, name of the journal, and date of your review submission (the “Review Data”) will then be transmitted to Publons upon publication of the manuscript. If you have already registered at Publons, they will notify you of the receipt of this review and update your profile as per your settings and their policy. If you are not registered with Publons, you will receive an email from them asking you to register in order for them to be able to recognize your review on your new profile page. Publons may use the Review Data to generate derivative metadata for the benefit of Publons and you as a reviewer, carefully considering the sensitivity of such information. For example, Publons may verify your record as a reviewer by updating your profile published on its webservice if you have registered for such service or help editors to identify candidate reviewers. Please find the details of processing in Publons’ privacy policy https://publons.com/about/terms: **Yes**\n* Declaration of competing interests: **I declare that I have no competing interests.**\n* Reviewer Publication Consent. I agree for my report to be made available under an Open Access Creative Commons CC-BY License (http://creativecommons.org/licenses/by/4.0) if this manuscript is accepted for publication. Any comments that I do not wish to be included in the published report have been included as confidential comments to the editor, which will not be published.: **I agree to the terms of the CC-BY 4.0 license; please do not publish my name with my report. (default)**\n* Is the study design appropriate to answer the research question (including the use of appropriate controls), and are the conclusions supported by the evidence presented?: **Yes**\n* Are the methods sufficiently described to allow the study to be repeated?: **Yes**\n* Is the use of statistics and treatment of uncertainties appropriate?: **Yes**\n* Is the presentation of the work clear?: **Yes**\n* Are the images in this manuscript (including electrophoretic gels and blots) free from apparent manipulation?: **Yes**\n"},{"type":"reviewerAgreed","content":"","date":"2020-09-07T12:00:00+00:00","index":3,"fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-08-28T12:00:00+00:00","index":2,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2020-08-27T12:00:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2020-08-27T12:00:00+00:00","index":1,"fulltext":""},{"type":"editorAssigned","content":"","date":"2020-08-24T12:00:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2020-08-21T12:00:00+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2020-08-21T12:00:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6f302b87-2fbf-4e79-9b8c-f559ec7c7f27","owner":[],"postedDate":"January 15th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":1383575,"name":"Anesthesiology \u0026 Pain Medicine"}],"tags":[],"updatedAt":"2021-01-31T15:02:31+00:00","versionOfRecord":{"articleIdentity":"rs-52905","link":"https://doi.org/10.1186/s12871-021-01243-7","journal":{"identity":"bmc-anesthesiology","isVorOnly":false,"title":"BMC Anesthesiology"},"publishedOn":"2021-01-27 15:00:33","publishedOnDateReadable":"January 27th, 2021"},"versionCreatedAt":"2021-01-15 11:36:38","video":"","vorDoi":"10.1186/s12871-021-01243-7","vorDoiUrl":"https://doi.org/10.1186/s12871-021-01243-7","workflowStages":[]},"version":"v3","identity":"rs-52905","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-52905","identity":"rs-52905","version":["v3"]},"buildId":"GqpaHPwrfC8PjnIFayRh5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}