The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study

The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study | 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 Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study Jiating Cheng, Qirui Sun, Jianliang Sun, Yuan Cheng, Weiping Lei This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3936426/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background To evaluate and compare the effects of a modified deep serratus anterior plane block (DSPB) combined with general anesthesia on surgical stress and perioperative neurocognitive disorder (PND) in elderly patients undergoing thoracic surgery, providing a new way to reduce the occurrence of PND in elderly patients undergoing thoracic surgery. Methods Sixty-six patients undergoing thoracic surgery were randomly assigned to receive either single-shot DSPB or local block after tracheal intubation using ropivacaine 0.5% 20 mL. The primary outcomes were the visual analog scale (VAS) score at each time point and the Montreal cognitive assessment (MoCA) score before surgery and after discharge from the hospital (or seventh day postoperative). Secondary outcomes included drug consumption, vital signs, blood gas analysis, malondialdehyde, superoxide dismutase, and serum cortisol levels. Results Sixty patients were eventually enrolled in this study. The VAS scores were significantly lower in the DSPB group than in the local block group (all P < 0.05). The difference in blood gas analysis index TCO2 (27.71 ± 3.49 vs 29.31 ± 2.26) in the two groups was statistically significant (P < 0.05). The length of hospitalization in the DSPB group was shorter than that in the local block group (6.03 ± 1.35 vs 7.20 ± 1.49), and the difference was statistically significant (P < 0.05). There were no statistically significant differences in MoCA scores before surgery and after hospitalization (or the seventh day postoperative), stress indices, vital signs, bispectral index value, blood gas analysis (except TCO 2 ), and drug addiction during extubation at each time point (all P > 0.05). Conclusion Compared with local block, DSPB provided a superior analgesic effect with a lower VAS score and shorter length of hospitalization in elderly ptalatients undergoing thoracic surgery. It does not require ultrasound equipment, making it simpler and easier to operate, and is especially suitable for widespread implementation in grassroots hospitals. perioperative neurocognitive disorder thoracic surgery general anesthesia deep serratus anterior plane block (DSPB) elderly patients Figures Figure 1 Figure 2 Introduction Perioperative neurocognitive disorder (PND), a generic term for pre-and postoperative cognitive impairment, usually refers to damage to memory, learning, attention, or psychomotor performance ( 1 ). In recent years, as the aging social population has gradually increased, there has been a corresponding rise in the proportion of elderly individuals in the surgical population. However, the exact cause of cognitive decline after anesthesia and surgery remains unclear. The type and dosage of general anesthesia drugs, the surgical traumatic stress response, inflammatory response, postoperative infection, and postoperative respiratory complications can contribute to early PND ( 2 – 3 ). Among these, perioperative stress reaction is an important risk factor for PND in elderly patients ( 4 ). Therefore, based on the current basic and clinical research results, controlling or effectively reducing the stress response in elderly patients during the perioperative period can effectively reduce the occurrence of PND. Traditional open thoracic surgery is generally more traumatic. Although the surgery under video thoracoscopy, which is less traumatic than traditional open surgery, is more commonly used in clinical practice, it provides strong stimulation, causing a stress response( 5 ). Therefore, the incidence of PND in elderly patients undergoing thoracic surgery is higher than that in patients undergoing other surgeries( 6 ). Therefore, special attention should be paid to reducing the perioperative stress response in elderly patients undergoing thoracic surgery, aiming to reduce the incidence of PND. The serratus anterior plane block (SAPB) is a novel chest wall nerve block technique. SAPB demonstrates a unique capability to infiltrate and effectively block the lateral cutaneous branches of the T2-T9 intercostal nerves while also extending its reach to the long thoracic and thoracic dorsal nerves( 7 – 8 ). Notably, SAPB achieves an analgesic effect that surpasses the capabilities of both the thoracic paravertebral block (TPVB) and intercostal nerve block (INB)( 9 ). Research findings indicate that the superficial SAPB achieves a block range spanning T2–T9, with an average duration of 12 hours (700–780 minutes). In contrast, DSPB exhibited a relatively shorter duration and a narrower block range. Nevertheless, the DSPB maintains a block time ranging from 3.5 to 10 hours, covering typical thoracic incision positions encountered in basic clinical practice ( 10 ). Currently, detailed reports on the intra- and postoperative analgesic effects of DSPB in patients undergoing thoracic surgery are lacking. Moreover, the inhibitory effect of DSPB on the stress response during surgery in elderly patients and its subsequent effects on PND remains unclear. This study aimed to assess the effects of a modified DSPB combined with general anesthesia on surgical stress, postoperative pain, and Montreal cognitive assessment (MoCA) scores related to PND in elderly patients undergoing thoracic surgery. This study aimed to offer novel insights into perioperative analgesia and strategies for the prevention and treatment of PND in elderly patients undergoing thoracic surgery. Materials and methods Study design The study was approved by the Medical Ethics Committee of the Affiliated Hangzhou First People’s Hospital, School of Medicine, Westlake University (ethical approval number: KY-20230208–0019 − 01 11/18/2020), and registration was completed at the China Clinical Trials Registry (registration number: ChiCTR2300068717 28/02/2023). In accordance with ethical guidelines, informed consent was obtained through signed agreements with the patients themselves or, when applicable, with their families. Study population In this study, the inclusion criteria were as follows: ( 1 ) age: 65 to 80 years, ( 2 ) ASA classification I-II ( 3 ) scheduled for thoracic surgery ( 4 ) ability to sign the informed consent form independently. The exclusion criteria were as follows: ( 1 ) mini-mental state examination (MMSE) scale score ≤ 23 points, ( 2 ) neurological diseases predisposing to cognitive decline, such as Parkinson's disease, vascular dementia, cerebral hemorrhage, brain tumor, hepatic encephalopathy, ( 3 ) history of cognitive disorders, including cerebral hemorrhage, drug abuse, intracranial tumors, encephalitis, brain trauma, were excluded, ( 4 ) inability to complete psychological tests due to visual impairment, hearing impairment, or physical dysfunction, ( 5 ) history of congenital intellectual disability or mental illness, ( 6 ) known hyperalgesia or dysalgesia, ( 7 ) refractory cancer pain, ( 8 ) illiteracy. A total of 66 patients who underwent thoracic surgery were observed from October 2021 to June 2022, and 60 who met the inclusion criteria were included in the final analysis. Study protocol The patients were grouped using a random number table, and 66 patients were randomized into DSPB group (n = 33)and Local group ༈n = 33༉. Informed consent was obtained from all patients one day prior to surgery, and their cognitive function was assessed using the MoCA scale. All patients were instructed to avoid eating for 8 hours and drinking for 4 hours before surgery, and none of them took any preoperative medication. The patients were monitored continuously using ECG, pulse oximetry, respiratory rate, mean arterial blood pressure (MAP), and bispectral index (BIS) values. After a period of pre-oxygenation, all patients had general anesthesia induced with intravenous midazolam (0.05 mg/kg), propofol (2 mg/kg), sufentanil (0.6 µg/kg), and cisatracurium (0.2 mg/kg). All patients were intubated with a Shiley endobronchial tube to achieve lung isolation, and fiberoptic bronchoscopy was used to confirm the correct positioning. The hemodynamic goal was to maintain the systolic blood pressure within 20% of baseline. Anesthesia maintenance comprised continuous inhalation of sevoflurane (1–2%), continuous infusion of remifentanil (0.1–0.2 µg/kg·min), continuous infusion of propofol (4–6 mg/kg·h), and additional cis-atracurium as required. Throughout the operation, BIS values were maintained between 40 and 60 mmHg. P ET CO2 was maintained between 35 and 40 mmHg. Mechanical ventilation settings, the need for invasive hemodynamic monitoring, and central venous access were at the discretion of the treating anesthesiologist. The envelopes were opened after the induction of general anesthesia to reveal the group allocation. Blocks were performed under fully aseptic conditions according to randomization before the commencement of the surgery. All patients received ropivacaine 0.5% in a 20 mL volume, administered as part of the specified blocks. The DSPB group underwent a modified DSPB after tracheal intubation, following the methods for unilateral DSPB under ultrasound guidance. Specifically, at the 4th or 5th rib of the midaxillary line on the same side as the surgical incision, the surgeon inserted a No.7 injection needle vertically and injected 0.5% ropivacaine (20 mL) after confirming proper needle placement. Conversely, the Local group received local infiltration of 0.5% ropivacaine (20 mL) at the surgical incision site, and the completion time of the block was recorded. Subsequently, the patient’s vital signs and P ET CO2 were recorded at five additional time points: after endotracheal intubation, at incision and endoscopy, one hour after the block, at the end of surgery, and 30 minutes after surgery. Simultaneously, venous blood (4 mL) was collected at four time points: after endotracheal intubation (T0), at incision and endoscopy (T1), 1 hour after the block (T2), and 30 minutes after surgery (T3). The serum, obtained through centrifugation, was stored at -80℃ for subsequent determination of malondialdehyde (MDA), superoxide dismutase (SOD), and serum cortisol. Additionally, one hour post-operation, arterial blood (1 mL) was collected for blood gas analysis to determine relevant indices. After surgery, patients were provided with a self-controlled analgesia pump (sufentanil 100ug, dexmedetomidine 100ug, tropisetron 4 mg) with a continuous infusion rate of 2 mL/h, a patient-controlled dose of 2 mL/h, and a locking time of 30 minutes. Postoperative pain was evaluated using the visual analog scale (VAS) at extubation and 30 minutes after extubation, two hours after extubation, and six hours after extubation. Drug use was recorded before and after extubation. On the seventh day after surgery or on the day of discharge, the cognitive function of the patients was assessed again using the MoCA scale. Statistical analysis The statistical software SPSS version 26.0 and GraphPad Prism version 8.0 were used for data processing. Sex, surgical method, education level, and drug use during the extubation period were analyzed using a chi-square test. Age, length of hospital stay, and intraoperative blood gas indicators were analyzed using independent sample t-tests. For measures involving repeated observations, the generalized estimation equation was employed to compare statistical differences between groups at different time points. Statistical significance was set at P < 0.05. Guided by relevant literature and the sample size formula (n=(〖(Z_α + Z_β)〗^2 (1 + 1⁄k)σ^2)/δ^2, k = 1)for group comparison with parameters set at α = 0.05, 1-β = 0.8, and an expected 10% loss rate in follow-up, a total of 66 subjects were enrolled in this study, with 33 cases allocated to each group. Results Disposition and baseline characteristics of subjects Between October 2021 and June 2022, 66 patients aged 65–80 years were enrolled in the study. Of these, six patients were excluded, with three lost to follow-up(n = 3), two experiencing adverse reactions (n = 2), and one exiting (n = 2). Thirty patients were in the DSPB group and 30 were in the Local group. Patients underwent standardized anesthetic and surgical procedures and completed all evaluation assessments. Finally, we performed a statistical analysis of the patients’ data and created a flow diagram for the trial (Fig. 1 ). There were no significant differences in sex, age, type of surgery, or educational level, as shown in Table 1 . Comparison of VAS score , drug use, Stress indices, MAP, HR, SpO 2 , P ET CO 2 , BIS, MoCA The VAS score in the local group was significantly lower than that in the local group at each time point (P < 0.05),as shown in Fig. 2 (A). There were no significant differences in drug use during tracheal extubation, as shown in Table 2 . Stress indices, such as MDA, SOD, and cortisol were detected in the serum (P > 0.05), as shown in Figs. 2 (B,C,D). There were no significant differences in MAP (P = 0.223), HR (P = 0.403), SpO 2 (P = 0.197), P ET CO 2 (P = 0.936), or BIS (P = 0.511), as shown and Tables 3 –7T0 .(Entering the operating room); T1(After tracheal intubation); T2༈the thoracoscope enters through the incision); T3( One hour after the nerve block);T4(At the end of surgery); T5(30 minutes after surgery). There was no significant difference in the intraoperative blood gas analysis between the two groups, except for TCO2 (P < 0.05)( Table 8 ). The MoCA scale score was not significantly different between the two groups, as shown in Fig. 2 (E). The length of hospital stay was shorter in the DSPB group compared to the local group, as shown in Fig. 2 (F). Discussion The novelty of this clinical trial lies in the observation of a modified deep SAPB under general anesthesia to determine its potential to reduce surgical stress and prevent perioperative neurocognitive impairment. Dr. Rafael Blanco first described SAPB in 2013, where local anesthetic penetration was observed at the midaxillary line in the superficial or deep interfascial plane of the serratus anterior muscle( 11 ). Mayes et al. performed diffusion tests with methylene blue solution on cadaver specimens and showed that the extension area included the lateral cutaneous branches of the second to sixth intercostal nerves, long thoracic nerve, and thoracodorsal nerve in the anterior serratus space( 12 ). Anatomically, SAPB can not only block the intercostal nerve by infiltrating the lateral cutaneous branch of the intercostal nerve but also infiltrate the long thoracic nerve and thoracodorsal nerve, providing more comprehensive analgesia in the anterolateral chest wall than TEB, TPVB, and INB( 13 – 14 ). In this clinical trial, we assessed the postoperative pain scores (VAS score) in two groups, DSPB group and Local group. DSPB group had lower scores than Local group,indicating that the modified deep serratus anterior muscle had a more effective analgesic effect. Neuroendocrine changes induced by surgical stress mainly affect the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medulla axis. Surgery and anesthesia are the main stressors affecting patients’ perioperative stress responses( 15 ). Currently, double-lumen endotracheal tubes are commonly used in thoracic surgery for lung isolation under general anesthesia. However, general anesthesia alone may not completely block the increased secretion of the pituitary gland and adrenal medulla caused by stimulation, such as intubation and surgery. Surgical stimulation can increase the concentration of catecholamines and cortisol in patients' blood, resulting in hemodynamic changes, such as increased blood pressure and heart rate. Propofol has been suggested to have limited attenuation of the hypothalamic axis activation in thoracic surgery, and remifentanil is often used to control the stress responses, which is generally negligible in this context( 16 ). Many studies have shown that combined anesthesia to block incision pain can reduce stress responses, such as cardiovascular responses. This reduction can help avoid a prolonged recovery period caused by the addition of anesthetic drugs to maintain stable hemodynamics( 17 ). As a nerve block method commonly used in thoracic surgery, DSPB can block pain signal transmission from thoracic incision to the spinal cord, thereby reducing perioperative stress reactions, and cardiovascular adverse reactions, and relieving postoperative incision pain in patients undergoing thoracic surgery. In this trial, no significant differences were observed in MDA, SOD, and cortisol between the groups. However, some studies have confirmed oxidative stress damage in the hippocampi of PND mice, manifesting as decreased SOD activity and increased ROS and MDA expression in the hippocampus ( 18 ). We also compared the MAP, HR, and SpO2 between the two groups at each time point, and the differences were not statistically significant. Therefore, the hemodynamics in both groups were relatively stable. Elevated glucocorticoid levels induced by stress can increase blood glucose levels. Therefore, we compared the blood gas indices between the two groups during surgery to examine their impact. The results showed a significant difference only in TCO2 (P < 0.05), with DSPB group exhibiting lower total carbon dioxide levels compared to Local group.This suggests that the modified DSPB may not only enhance local analgesia but also improve the ventilation-to-blood flow ratio in the blocked lung during one-lung ventilation, potentially preventing the accumulation of carbon dioxide in the body to a certain extent. Thus, the modified DSPB may play a role in regulating the autonomic nervous system. The results showed that there were no significant differences in blood glucose levels between the two groups. Jung et al. suggested that a high propofol infusion rate for deep anesthesia in pulmonary surgery can reduce the perioperative glucose response more effectively than shallow anesthesia but does not affect the immediate postoperative blood glucose results( 19 ). The effect of the modified DSPB on glucose may require an extended follow-up time to explore its clinical significance further. Therefore, further investigation is warranted to assess the effect of the modified DSPB on stress control during thoracic surgery. The surgical stress response has been recognized as a risk factor for perioperative neurocognitive disorders, especially in the elderly surgical population. Studies have confirmed that nearly 10% of elderly people have objective cognitive impairment three months after noncardiac surgery, as determined by a series of neuropsychological tests ( 20 ). In this trial, we used the MoCA scale to assess the cognitive function of patients scheduled for elective thoracic surgery the day before the operation. The sensitivity of the MoCA scale to mild cognitive dysfunction was higher than that of the MMSE scale, especially in elderly patients. However, the MoCA scale also has certain limitations, including factors, such as education level, and age of patients( 21 – 22 ). In this trial, elderly patients, all aged over 65, and most educated at the junior high school level, were followed up till the seventh day after surgery or the day of discharge (within seven days of hospitalization). Their cognitive function was reassessed with the MoCA scale. The results showed no statistically significant difference in MoCA scores between the two groups. Notably, patients in the modified DSPB group had shorter hospital stays. However, MoCA scores in both groups were higher after surgery compared to preoperative assessments. The reasons for this could be that the time between the two assessments was too short and that the patients were familiar with the scale process and content. Due to the limitations of our research conditions, our study was confined to the hospitalization period of patients, and the scope of the MoCA score assessment was limited. This study introduces an innovative technique for the completion of a modified DSPB without ultrasound guidance. This technique relies primarily on the anatomical structure of the serratus anterior muscle and specifically targets the deep plane between the serratus anterior muscle, external intercostal muscle, and ribs. It does not require ultrasound equipment, making it a simpler and more easily operable procedure that is particularly suitable for widespread implementation in grassroots hospitals. In our preliminary experiments, we observed that the blocking range and ultrasound images of the modified DSPB were comparable to those of the traditional DSPB, and no adverse reactions have been identified thus far. Compared to local infiltration, modified DSPB demonstrates advantages such as superior analgesia, lower postoperative pain scores, and shorter hospital stays. This study has several limitations, including a small sample size, absence of a double-blind method, relatively short follow-up interval, lack of a comprehensive neuropsychological evaluation system to assess cognitive function comprehensively, and no record of postoperative analgesic pump drug consumption. To address these limitations, it is imperative to expand the sample size, extend the follow-up duration, and enhance the evaluation methods for PND. Future research should focus on investigating the impact of the modified DSPB on surgical stress and PND in elderly patients undergoing thoracic surgery. Conclusions In comparison to local infiltration, the modified DSPB in elderly patients undergoing thoracic surgery demonstrated superior analgesic efficacy, as evidenced by lower VAS scores, and led to a shorter hospital stay. However, no significant differences were observed in perioperative stress levels or MoCA scores related to PND. List Of Abbreviations bispectral index (BIS), malondialdehyde (MDA), mean arterial blood pressure (MAP), mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), perioperative neurocognitive disorder (PND), serratus anterior plane block (SAPB), superoxide dismutase (SOD), thoracic paravertebral block (TPVB), visual analog scale (VAS). Declarations Ethics approval and consent to participate This study was performed in line with the principles of the Declaration of Helsinki. Approved by the Medical Ethics Committee of the Affiliated Hangzhou First People’s Hospital, School of Medicine, Westlake University (KY-20230208–0019-01 11/18/2020), and registration was completed at the China Clinical Trials Registry (registration number: ChiCTR2300068717 28/02/2023). Written informed consent was obtained through signed agreements with the patients themselves or, when applicable, with their families. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare no competing interests. Funding This work was supported by Medical Science and Technology Project of Zhejiang Province (No. 2021KY872), the Construction Fund of Key Medical Disciplines of Hangzhou (Anesthesia and Pain Medicine OO20200484). Authors' contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Jiating Cheng,Qirui Sun and Jianliang Sun. Yuan Cheng is mainly responsible for the paper or experimental design, paper revision and financial support. The first draft of the manuscript was written by Jiating Cheng and Weiping Lei and all authors commented on previous versions of the manuscript. Corresponding author Yuan Cheng and Weiping Lei contributed equally to this work. All authors read and approved the final manuscript. Acknowledgements The authors would like to thank Hangzhou First People’s Hospital for providing a platform for clinical trials. At the same time, we would also like to thank all the medical staff of the Department of Anesthesiology of Hangzhou First People’s Hospital for their help and guidance for this study. Authors' information 1 Department of Anesthesiology, Sir Run Run Shaw Hospital College of Medicine Zhejiang University, Hangzhou 3100016 China. 2 Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, School of Medicine, Westlake University, Hangzhou 310006, China. References Evered L, Silbert B, Knopman DS et al. 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Dementia & Neuropsychologia 2020; 14:145-152. Tables Table 1 Demographic data Local (n = 30) DSPB (n = 30) P Gender Female 12 (40%) 16 (53%) 0.301 Male 18 (60%) 14 (47%) Age(years) 68.57 ± 7.1 68.43 ± 4.6 0.931 Surgery Wedge resection 18 (60%) 16 (63%) 0.652 Lobectomy 10 (33%) 12 (37%) Lung puncture 1 (3.3%) 0 Thoracotomy 1 (3.3%) 2 (6.6%) Education Grade school 7 (23%) 4 (13.3%) 0.822 Junior high school 11 (37%) 13 (43%) Senior high school 6 (20%) 4 (13.3%) Vocational school 2 (6.6%) 4 (13.3%) Junior college 3 (10%) 4 (13.3%) University 1 (3.3%) 1 (3.3%) Table 2 Comparison of drug use in the tracheal extubation period Local(n = 30) DSPB(n = 30) P Analgesic Sufentanil(5µg) 2(6.7%) 1(3.3%) Sufentanil(10µg) 4(13.3%) 1(3.3%) 0.565 Flurbiprofenaxetil 3(10%) 0 Other Dexmedetomidine 2(6.7%) 2(6.7%) neostigmine 0 1(3.3%) 0.659 atropine 0 1(3.3%) propofol 1(3.3%) 1(3.3%) Table 3 Comparison of mean arterial pressure (MAP) Local(n = 30) DSPB(n = 30) P T0 105.02 ± 2.70 112.66 ± 2.68 0.223 T1 86.47 ± 2.43 102.03 ± 4.40 T2 91.63 ± 2.31 87.03 ± 2.86 T3 82.40 ± 2.06 78.76 ± 1.69 T4 81.04 ± 1.83 80.00 ± 2.15 T5 98.28 ± 2.70 98.40 ± 3.93 Table 4 Comparison of heart rate (HR) Local(n = 30) DSPB(n = 30) P T0 69.57 ± 2.03 79.23 ± 2.50 0.403 T1 75.23 ± 2.71 78.83 ± 2.72 T2 70.70 ± 2.49 68.67 ± 1.89 T3 68.17 ± 1.32 64.63 ± 1.70 T4 64.43 ± 1.90 66.33 ± 2.10 T5 77.47 ± 2.13 79.13 ± 2.70 Table 5 Comparison of oxygen saturation (SpO 2 ) Local(n = 30) DSPB(n = 30) P T0 96.23 ± 0.38 95.70 ± 0.67 0.197 T1 98.70 ± 0.24 98.30 ± 0.43 T2 98.67 ± 0.28 98.17 ± 0.33 T3 97.87 ± 0.39 97.83 ± 0.47 T4 99.27 ± 0.15 99.27 ± 0.16 T5 98.33 ± 0.32 97.73 ± 0.50 Table 6 Comparison of end-tidal pressure of carbon dioxide (P ET CO 2 ) Local(n = 30) DSPB(n = 30) P T1 37.13 ± 0.88 38.03 ± 1.06 0.936 T2 38.60 ± 0.93 38.50 ± 1.06 T3 39.23 ± 1.04 38.20 ± 0.83 T4 39.53 ± 1.13 39.43 ± 1.11 Table 7 Comparison of depth of anesthesia (BIS) Local(n = 30) DSPB(n = 30) P T0 94.40 ± 0.62 93.50 ± 0.50 0.511 T1 48.60 ± 2.45 47.67 ± 1.98 T2 47.67 ± 1.39 47.17 ± 1.70 T3 48.03 ± 1.35 45.50 ± 1.60 T4 52.20 ± 2.42 53.33 ± 2.40 T5 79.27 ± 1.89 77.90 ± 3.11 Table 8 Comparison of intraoperative arterial blood gas indexes Local(n = 30) DSPB(n = 30) P PCO 2 191.4 ± 98.40 197.13 ± 112.63 0.117 TCO 2 29.31 ± 2.26 * 27.71 ± 3.49 * < 0.05 HCO 3 − 27.65 ± 2.11 26.63 ± 2.39 0.084 Glu 6.06 ± 0.96 6.62 ± 1.59 0.105 Lac 1.22 ± 0.49 1.53 ± 2.13 0.445 K + 3.69 ± 0.50 3.57 ± 0.51 0.334 BEecf 1.57 ± 2.20 0.29 ± 3.67 0.105 There were no significant differences in sex, age, type of surgery, or educational level, as shown in Table 1. There were no significant differences in drug use during tracheal extubation, as shown in Table 2. There were no significant differences in MAP (P=0.223), HR (P=0.403), SpO 2 (P=0.197), P ET CO 2 (P=0.936), or BIS (P=0.511), as shown and Tables 3–7 There was no significant difference in the intraoperative blood gas analysis between the two groups, except for TCO2 (P < 0.05)( Table 8). T0 .(Entering the operating room); T1（After tracheal intubation); T2（the thoracoscope enters through the incision）; T3( One hour after the nerve block);T4(At the end of surgery); T5(30 minutes after surgery). Additional Declarations No competing interests reported. Supplementary Files CONSORTchecklist.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version 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. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board 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-3936426","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":275546604,"identity":"c5883ccc-37e3-4e6a-8519-ee6525c7bd5b","order_by":0,"name":"Jiating Cheng","email":"","orcid":"","institution":"Sir Run Run Shaw Hospital College of Medicine Zhejiang University","correspondingAuthor":false,"prefix":"","firstName":"Jiating","middleName":"","lastName":"Cheng","suffix":""},{"id":275546605,"identity":"e48fb116-6117-4758-8fa1-e015eb2d66eb","order_by":1,"name":"Qirui Sun","email":"","orcid":"","institution":"Hangzhou First People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Qirui","middleName":"","lastName":"Sun","suffix":""},{"id":275546606,"identity":"b1658d32-32e6-4d61-b5de-49451786fd7a","order_by":2,"name":"Jianliang Sun","email":"","orcid":"","institution":"Sir Run Run Shaw Hospital College of Medicine Zhejiang University","correspondingAuthor":false,"prefix":"","firstName":"Jianliang","middleName":"","lastName":"Sun","suffix":""},{"id":275546607,"identity":"f5f0b82a-5be5-4e23-b7ec-4c4945a9650d","order_by":3,"name":"Yuan Cheng","email":"","orcid":"","institution":"Hangzhou First People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yuan","middleName":"","lastName":"Cheng","suffix":""},{"id":275546608,"identity":"b7c7d110-c483-4582-9554-b35f3835bf3b","order_by":4,"name":"Weiping Lei","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/klEQVRIie3RMWsCMRTA8XcEzuXZrBcq+BUedBBB6lfJITh16FQcTw7i0g8Qv0PnzjkydDm8VYhDS6FTh7hZcFDB4pZzLDT/KQ/yGx4PIBb7g91AUgAQIEAyf5ezEXJehEl6IcySr6c9oU0buTynYqnsiArZQjqlyvzjpjfgL3TbVQ0SmMRvHwIEKyU0feFQf9MdrhwOWMHE8jVAslw5JIu0rmmCTw6HhUlZN0T6H8rtz8RiukIysoVkiXJwIo3K51qZKwjmi5/n4y60ZhZ8PUGhqzK4C++8fdJuvxlTUy12cnY/5rys/DZAzhmATP4Op+O2dyTcXPMxFovF/mMHD3FXlknJhqAAAAAASUVORK5CYII=","orcid":"","institution":"Hangzhou First People's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Weiping","middleName":"","lastName":"Lei","suffix":""}],"badges":[],"createdAt":"2024-02-07 09:59:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3936426/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3936426/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":51974060,"identity":"a278fa84-c100-4a4c-905b-c58a229546c7","added_by":"auto","created_at":"2024-03-04 19:05:17","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":27733,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3936426/v1/44bbf0c7fbeeeda10be16399.png"},{"id":51974059,"identity":"eed3c0fe-1f5c-40cf-a474-8ceae4159be6","added_by":"auto","created_at":"2024-03-04 19:05:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":80919,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(A). \u003c/strong\u003eDrug use during the extubation period.\u003cstrong\u003e \u003c/strong\u003eT0 (extubation); T1（30 minutes after extubation); T2（one hour after extubation; T3 (six hours after extubation);\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(B). \u003c/strong\u003eStress indexes include malondialdehyde (MDA), superoxide dismutase (SOD) and cortisol.\u003cstrong\u003e \u003c/strong\u003eAs shown in the figure, there was no statistically significant difference in serum MDA stress indices between Local group (black) and DSPB group(gray) at each time point. T0(after tracheal intubation); T1 (when thoracoscope access to incision); T2 (one hour after nerve block); T3 (30 minutes after surgery)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(C). \u003c/strong\u003eAs shown in the figure, there was no statistically significant difference in serum SOD stress indices between Local group (black) and DSPB group (gray) at each time point. T0 (after tracheal intubation); T1 (when thoracoscope access to incision); T2 (one hour after nerve block); T3 (30 minutes after surgery)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(D). \u003c/strong\u003eAs shown in the figure, there was no statistically significant difference in serum cortisol levels between Local group (black) and DSPBgroup (gray) at any time point. T0(after tracheal intubation); T1 (when thoracoscope access to incision); T2 (one hour after nerve block); T3 (30 minutes after surgery)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(E). \u003c/strong\u003eMontreal Cognitive Assessment Scale (MoCA scale)\u003cstrong\u003e. \u003c/strong\u003eAs shown in the figure, there was no statistically significant difference in the MoCA scale scores between Local group(black) and DSPB group (gray) at any time point. T0 (preoperative ): T1 (at discharge or seven days after surgery)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(F). \u003c/strong\u003eHospital stays.\u003cstrong\u003e \u003c/strong\u003eAs shown in the figure, there was a statistically significant difference in the length of hospital stay between the two groups; the length of hospital stay in DSPB group(gray) was shorter than that in Local group (black).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3936426/v1/b474acf4499f0a3788aba561.png"},{"id":56834173,"identity":"a7f71b15-903e-40d3-8d57-5b2fc4f36def","added_by":"auto","created_at":"2024-05-21 05:29:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":728110,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3936426/v1/5670fba7-a289-4e62-af65-5542bdf3de8a.pdf"},{"id":51974061,"identity":"744a6214-96a1-4161-81aa-d8036b640cf9","added_by":"auto","created_at":"2024-03-04 19:05:17","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":26595,"visible":true,"origin":"","legend":"","description":"","filename":"CONSORTchecklist.docx","url":"https://assets-eu.researchsquare.com/files/rs-3936426/v1/0e98a1b1e5af1cfd9347b742.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePerioperative neurocognitive disorder (PND), a generic term for pre-and postoperative cognitive impairment, usually refers to damage to memory, learning, attention, or psychomotor performance (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). In recent years, as the aging social population has gradually increased, there has been a corresponding rise in the proportion of elderly individuals in the surgical population. However, the exact cause of cognitive decline after anesthesia and surgery remains unclear. The type and dosage of general anesthesia drugs, the surgical traumatic stress response, inflammatory response, postoperative infection, and postoperative respiratory complications can contribute to early PND (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Among these, perioperative stress reaction is an important risk factor for PND in elderly patients (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Therefore, based on the current basic and clinical research results, controlling or effectively reducing the stress response in elderly patients during the perioperative period can effectively reduce the occurrence of PND.\u003c/p\u003e \u003cp\u003eTraditional open thoracic surgery is generally more traumatic. Although the surgery under video thoracoscopy, which is less traumatic than traditional open surgery, is more commonly used in clinical practice, it provides strong stimulation, causing a stress response(\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Therefore, the incidence of PND in elderly patients undergoing thoracic surgery is higher than that in patients undergoing other surgeries(\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Therefore, special attention should be paid to reducing the perioperative stress response in elderly patients undergoing thoracic surgery, aiming to reduce the incidence of PND.\u003c/p\u003e \u003cp\u003eThe serratus anterior plane block (SAPB) is a novel chest wall nerve block technique. SAPB demonstrates a unique capability to infiltrate and effectively block the lateral cutaneous branches of the T2-T9 intercostal nerves while also extending its reach to the long thoracic and thoracic dorsal nerves(\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Notably, SAPB achieves an analgesic effect that surpasses the capabilities of both the thoracic paravertebral block (TPVB) and intercostal nerve block (INB)(\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eResearch findings indicate that the superficial SAPB achieves a block range spanning T2\u0026ndash;T9, with an average duration of 12 hours (700\u0026ndash;780 minutes). In contrast, DSPB exhibited a relatively shorter duration and a narrower block range. Nevertheless, the DSPB maintains a block time ranging from 3.5 to 10 hours, covering typical thoracic incision positions encountered in basic clinical practice (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Currently, detailed reports on the intra- and postoperative analgesic effects of DSPB in patients undergoing thoracic surgery are lacking. Moreover, the inhibitory effect of DSPB on the stress response during surgery in elderly patients and its subsequent effects on PND remains unclear. This study aimed to assess the effects of a modified DSPB combined with general anesthesia on surgical stress, postoperative pain, and Montreal cognitive assessment (MoCA) scores related to PND in elderly patients undergoing thoracic surgery. This study aimed to offer novel insights into perioperative analgesia and strategies for the prevention and treatment of PND in elderly patients undergoing thoracic surgery.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003e The study was approved by the Medical Ethics Committee of the Affiliated Hangzhou First People\u0026rsquo;s Hospital, School of Medicine, Westlake University (ethical approval number: KY-20230208\u0026ndash;0019\u0026thinsp;\u0026minus;\u0026thinsp;01 11/18/2020), and registration was completed at the China Clinical Trials Registry (registration number: ChiCTR2300068717 28/02/2023). In accordance with ethical guidelines, informed consent was obtained through signed agreements with the patients themselves or, when applicable, with their families.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eIn this study, the inclusion criteria were as follows: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) age: 65 to 80 years, (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) ASA classification I-II (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) scheduled for thoracic surgery (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) ability to sign the informed consent form independently. The exclusion criteria were as follows: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) mini-mental state examination (MMSE) scale score\u0026thinsp;\u0026le;\u0026thinsp;23 points, (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) neurological diseases predisposing to cognitive decline, such as Parkinson's disease, vascular dementia, cerebral hemorrhage, brain tumor, hepatic encephalopathy, (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) history of cognitive disorders, including cerebral hemorrhage, drug abuse, intracranial tumors, encephalitis, brain trauma, were excluded, (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) inability to complete psychological tests due to visual impairment, hearing impairment, or physical dysfunction, (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) history of congenital intellectual disability or mental illness, (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e) known hyperalgesia or dysalgesia, (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) refractory cancer pain, (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e) illiteracy. A total of 66 patients who underwent thoracic surgery were observed from October 2021 to June 2022, and 60 who met the inclusion criteria were included in the final analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStudy protocol\u003c/h2\u003e \u003cp\u003eThe patients were grouped using a random number table, and 66 patients were randomized into DSPB group (n\u0026thinsp;=\u0026thinsp;33)and Local group ༈n\u0026thinsp;=\u0026thinsp;33༉. Informed consent was obtained from all patients one day prior to surgery, and their cognitive function was assessed using the MoCA scale. All patients were instructed to avoid eating for 8 hours and drinking for 4 hours before surgery, and none of them took any preoperative medication.\u003c/p\u003e \u003cp\u003eThe patients were monitored continuously using ECG, pulse oximetry, respiratory rate, mean arterial blood pressure (MAP), and bispectral index (BIS) values. After a period of pre-oxygenation, all patients had general anesthesia induced with intravenous midazolam (0.05 mg/kg), propofol (2 mg/kg), sufentanil (0.6 \u0026micro;g/kg), and cisatracurium (0.2 mg/kg). All patients were intubated with a Shiley endobronchial tube to achieve lung isolation, and fiberoptic bronchoscopy was used to confirm the correct positioning. The hemodynamic goal was to maintain the systolic blood pressure within 20% of baseline.\u003c/p\u003e \u003cp\u003eAnesthesia maintenance comprised continuous inhalation of sevoflurane (1\u0026ndash;2%), continuous infusion of remifentanil (0.1\u0026ndash;0.2 \u0026micro;g/kg\u0026middot;min), continuous infusion of propofol (4\u0026ndash;6 mg/kg\u0026middot;h), and additional cis-atracurium as required. Throughout the operation, BIS values were maintained between 40 and 60 mmHg. P\u003csub\u003eET\u003c/sub\u003eCO2 was maintained between 35 and 40 mmHg. Mechanical ventilation settings, the need for invasive hemodynamic monitoring, and central venous access were at the discretion of the treating anesthesiologist.\u003c/p\u003e \u003cp\u003eThe envelopes were opened after the induction of general anesthesia to reveal the group allocation. Blocks were performed under fully aseptic conditions according to randomization before the commencement of the surgery. All patients received ropivacaine 0.5% in a 20 mL volume, administered as part of the specified blocks.\u003c/p\u003e \u003cp\u003eThe DSPB group underwent a modified DSPB after tracheal intubation, following the methods for unilateral DSPB under ultrasound guidance. Specifically, at the 4th or 5th rib of the midaxillary line on the same side as the surgical incision, the surgeon inserted a No.7 injection needle vertically and injected 0.5% ropivacaine (20 mL) after confirming proper needle placement. Conversely, the Local group received local infiltration of 0.5% ropivacaine (20 mL) at the surgical incision site, and the completion time of the block was recorded. Subsequently, the patient\u0026rsquo;s vital signs and P\u003csub\u003eET\u003c/sub\u003eCO2 were recorded at five additional time points: after endotracheal intubation, at incision and endoscopy, one hour after the block, at the end of surgery, and 30 minutes after surgery. Simultaneously, venous blood (4 mL) was collected at four time points: after endotracheal intubation (T0), at incision and endoscopy (T1), 1 hour after the block (T2), and 30 minutes after surgery (T3). The serum, obtained through centrifugation, was stored at -80℃ for subsequent determination of malondialdehyde (MDA), superoxide dismutase (SOD), and serum cortisol.\u003c/p\u003e \u003cp\u003eAdditionally, one hour post-operation, arterial blood (1 mL) was collected for blood gas analysis to determine relevant indices. After surgery, patients were provided with a self-controlled analgesia pump (sufentanil 100ug, dexmedetomidine 100ug, tropisetron 4 mg) with a continuous infusion rate of 2 mL/h, a patient-controlled dose of 2 mL/h, and a locking time of 30 minutes.\u003c/p\u003e \u003cp\u003ePostoperative pain was evaluated using the visual analog scale (VAS) at extubation and 30 minutes after extubation, two hours after extubation, and six hours after extubation. Drug use was recorded before and after extubation. On the seventh day after surgery or on the day of discharge, the cognitive function of the patients was assessed again using the MoCA scale.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe statistical software SPSS version 26.0 and GraphPad Prism version 8.0 were used for data processing. Sex, surgical method, education level, and drug use during the extubation period were analyzed using a chi-square test. Age, length of hospital stay, and intraoperative blood gas indicators were analyzed using independent sample t-tests. For measures involving repeated observations, the generalized estimation equation was employed to compare statistical differences between groups at different time points. Statistical significance was set at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Guided by relevant literature and the sample size formula (n=(〖(Z_α\u0026thinsp;+\u0026thinsp;Z_β)〗^2 (1\u0026thinsp;+\u0026thinsp;1\u0026frasl;k)σ^2)/δ^2, k\u0026thinsp;=\u0026thinsp;1)for group comparison with parameters set at α\u0026thinsp;=\u0026thinsp;0.05, 1-β\u0026thinsp;=\u0026thinsp;0.8, and an expected 10% loss rate in follow-up, a total of 66 subjects were enrolled in this study, with 33 cases allocated to each group.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDisposition and baseline characteristics of subjects\u003c/h2\u003e \u003cp\u003eBetween October 2021 and June 2022, 66 patients aged 65\u0026ndash;80 years were enrolled in the study. Of these, six patients were excluded, with three lost to follow-up(n\u0026thinsp;=\u0026thinsp;3), two experiencing adverse reactions (n\u0026thinsp;=\u0026thinsp;2), and one exiting (n\u0026thinsp;=\u0026thinsp;2). Thirty patients were in the DSPB group and 30 were in the Local group. Patients underwent standardized anesthetic and surgical procedures and completed all evaluation assessments. Finally, we performed a statistical analysis of the patients\u0026rsquo; data and created a flow diagram for the trial (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThere were no significant differences in sex, age, type of surgery, or educational level, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cb\u003eComparison of VAS score\u003c/b\u003e, \u003cb\u003edrug use, Stress indices, MAP, HR, SpO\u003c/b\u003e\u003csub\u003e\u003cb\u003e2\u003c/b\u003e,\u003c/sub\u003e \u003cb\u003eP\u003c/b\u003e\u003csub\u003e\u003cb\u003eET\u003c/b\u003e\u003c/sub\u003e\u003cb\u003eCO\u003c/b\u003e\u003csub\u003e\u003cb\u003e2\u003c/b\u003e,\u003c/sub\u003e \u003cb\u003eBIS, MoCA\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe VAS score in the local group was significantly lower than that in the local group at each time point (P\u0026thinsp;\u003cem\u003e\u0026lt;\u003c/em\u003e\u0026thinsp;0.05),as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e2\u003c/span\u003e(A).\u003c/p\u003e \u003cp\u003eThere were no significant differences in drug use during tracheal extubation, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eStress indices, such as MDA, SOD, and cortisol were detected in the serum (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05), as shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e2\u003c/span\u003e(B,C,D).\u003c/p\u003e \u003cp\u003eThere were no significant differences in MAP (P\u0026thinsp;=\u0026thinsp;0.223), HR (P\u0026thinsp;=\u0026thinsp;0.403), SpO\u003csub\u003e2\u003c/sub\u003e (P\u0026thinsp;=\u0026thinsp;0.197), P\u003csub\u003eET\u003c/sub\u003eCO\u003csub\u003e2\u003c/sub\u003e (P\u0026thinsp;=\u0026thinsp;0.936), or BIS (P\u0026thinsp;=\u0026thinsp;0.511), as shown and Tables\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u0026ndash;7T0 .(Entering the operating room); T1(After tracheal intubation); T2༈the thoracoscope enters through the incision); T3( One hour after the nerve block);T4(At the end of surgery); T5(30 minutes after surgery).\u003c/p\u003e \u003cp\u003eThere was no significant difference in the intraoperative blood gas analysis between the two groups, except for TCO2 (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05)( Table\u0026nbsp;\u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe MoCA scale score was not significantly different between the two groups, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e2\u003c/span\u003e(E).\u003c/p\u003e \u003cp\u003eThe length of hospital stay was shorter in the DSPB group compared to the local group, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e2\u003c/span\u003e(F).\u003c/p\u003e "},{"header":"Discussion","content":"\u003cp\u003eThe novelty of this clinical trial lies in the observation of a modified deep SAPB under general anesthesia to determine its potential to reduce surgical stress and prevent perioperative neurocognitive impairment. Dr. Rafael Blanco first described SAPB in 2013, where local anesthetic penetration was observed at the midaxillary line in the superficial or deep interfascial plane of the serratus anterior muscle(\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). Mayes et al. performed diffusion tests with methylene blue solution on cadaver specimens and showed that the extension area included the lateral cutaneous branches of the second to sixth intercostal nerves, long thoracic nerve, and thoracodorsal nerve in the anterior serratus space(\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). Anatomically, SAPB can not only block the intercostal nerve by infiltrating the lateral cutaneous branch of the intercostal nerve but also infiltrate the long thoracic nerve and thoracodorsal nerve, providing more comprehensive analgesia in the anterolateral chest wall than TEB, TPVB, and INB(\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In this clinical trial, we assessed the postoperative pain scores (VAS score) in two groups, DSPB group and Local group. DSPB group had lower scores than Local group,indicating that the modified deep serratus anterior muscle had a more effective analgesic effect.\u003c/p\u003e \u003cp\u003eNeuroendocrine changes induced by surgical stress mainly affect the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medulla axis. Surgery and anesthesia are the main stressors affecting patients\u0026rsquo; perioperative stress responses(\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Currently, double-lumen endotracheal tubes are commonly used in thoracic surgery for lung isolation under general anesthesia. However, general anesthesia alone may not completely block the increased secretion of the pituitary gland and adrenal medulla caused by stimulation, such as intubation and surgery. Surgical stimulation can increase the concentration of catecholamines and cortisol in patients' blood, resulting in hemodynamic changes, such as increased blood pressure and heart rate. Propofol has been suggested to have limited attenuation of the hypothalamic axis activation in thoracic surgery, and remifentanil is often used to control the stress responses, which is generally negligible in this context(\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Many studies have shown that combined anesthesia to block incision pain can reduce stress responses, such as cardiovascular responses. This reduction can help avoid a prolonged recovery period caused by the addition of anesthetic drugs to maintain stable hemodynamics(\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). As a nerve block method commonly used in thoracic surgery, DSPB can block pain signal transmission from thoracic incision to the spinal cord, thereby reducing perioperative stress reactions, and cardiovascular adverse reactions, and relieving postoperative incision pain in patients undergoing thoracic surgery. In this trial, no significant differences were observed in MDA, SOD, and cortisol between the groups. However, some studies have confirmed oxidative stress damage in the hippocampi of PND mice, manifesting as decreased SOD activity and increased ROS and MDA expression in the hippocampus (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). We also compared the MAP, HR, and SpO2 between the two groups at each time point, and the differences were not statistically significant. Therefore, the hemodynamics in both groups were relatively stable.\u003c/p\u003e \u003cp\u003eElevated glucocorticoid levels induced by stress can increase blood glucose levels. Therefore, we compared the blood gas indices between the two groups during surgery to examine their impact. The results showed a significant difference only in TCO2 (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05), with DSPB group exhibiting lower total carbon dioxide levels compared to Local group.This suggests that the modified DSPB may not only enhance local analgesia but also improve the ventilation-to-blood flow ratio in the blocked lung during one-lung ventilation, potentially preventing the accumulation of carbon dioxide in the body to a certain extent. Thus, the modified DSPB may play a role in regulating the autonomic nervous system. The results showed that there were no significant differences in blood glucose levels between the two groups. Jung et al. suggested that a high propofol infusion rate for deep anesthesia in pulmonary surgery can reduce the perioperative glucose response more effectively than shallow anesthesia but does not affect the immediate postoperative blood glucose results(\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). The effect of the modified DSPB on glucose may require an extended follow-up time to explore its clinical significance further. Therefore, further investigation is warranted to assess the effect of the modified DSPB on stress control during thoracic surgery.\u003c/p\u003e \u003cp\u003eThe surgical stress response has been recognized as a risk factor for perioperative neurocognitive disorders, especially in the elderly surgical population. Studies have confirmed that nearly 10% of elderly people have objective cognitive impairment three months after noncardiac surgery, as determined by a series of neuropsychological tests (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). In this trial, we used the MoCA scale to assess the cognitive function of patients scheduled for elective thoracic surgery the day before the operation. The sensitivity of the MoCA scale to mild cognitive dysfunction was higher than that of the MMSE scale, especially in elderly patients. However, the MoCA scale also has certain limitations, including factors, such as education level, and age of patients(\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). In this trial, elderly patients, all aged over 65, and most educated at the junior high school level, were followed up till the seventh day after surgery or the day of discharge (within seven days of hospitalization). Their cognitive function was reassessed with the MoCA scale. The results showed no statistically significant difference in MoCA scores between the two groups. Notably, patients in the modified DSPB group had shorter hospital stays. However, MoCA scores in both groups were higher after surgery compared to preoperative assessments. The reasons for this could be that the time between the two assessments was too short and that the patients were familiar with the scale process and content. Due to the limitations of our research conditions, our study was confined to the hospitalization period of patients, and the scope of the MoCA score assessment was limited.\u003c/p\u003e \u003cp\u003eThis study introduces an innovative technique for the completion of a modified DSPB without ultrasound guidance. This technique relies primarily on the anatomical structure of the serratus anterior muscle and specifically targets the deep plane between the serratus anterior muscle, external intercostal muscle, and ribs. It does not require ultrasound equipment, making it a simpler and more easily operable procedure that is particularly suitable for widespread implementation in grassroots hospitals. In our preliminary experiments, we observed that the blocking range and ultrasound images of the modified DSPB were comparable to those of the traditional DSPB, and no adverse reactions have been identified thus far. Compared to local infiltration, modified DSPB demonstrates advantages such as superior analgesia, lower postoperative pain scores, and shorter hospital stays.\u003c/p\u003e \u003cp\u003eThis study has several limitations, including a small sample size, absence of a double-blind method, relatively short follow-up interval, lack of a comprehensive neuropsychological evaluation system to assess cognitive function comprehensively, and no record of postoperative analgesic pump drug consumption. To address these limitations, it is imperative to expand the sample size, extend the follow-up duration, and enhance the evaluation methods for PND. Future research should focus on investigating the impact of the modified DSPB on surgical stress and PND in elderly patients undergoing thoracic surgery.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn comparison to local infiltration, the modified DSPB in elderly patients undergoing thoracic surgery demonstrated superior analgesic efficacy, as evidenced by lower VAS scores, and led to a shorter hospital stay. However, no significant differences were observed in perioperative stress levels or MoCA scores related to PND.\u003c/p\u003e"},{"header":"List Of Abbreviations","content":"\u003cp\u003ebispectral index (BIS), malondialdehyde (MDA), mean arterial blood pressure (MAP), mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), perioperative neurocognitive disorder (PND), serratus anterior plane block (SAPB), superoxide dismutase (SOD), thoracic paravertebral block (TPVB), visual analog scale (VAS).\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was performed in line with the principles of the Declaration of Helsinki. Approved by the Medical Ethics Committee of the Affiliated Hangzhou First People\u0026rsquo;s Hospital, School of Medicine, Westlake University (KY-20230208\u0026ndash;0019-01 11/18/2020), and registration was completed at the China Clinical Trials Registry (registration number: ChiCTR2300068717 28/02/2023). Written informed consent was obtained through signed agreements with the patients themselves or, when applicable, with their families.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe 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\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by Medical Science and Technology Project of Zhejiang Province (No. 2021KY872), the Construction Fund of Key Medical Disciplines of Hangzhou (Anesthesia and Pain Medicine OO20200484).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Jiating Cheng,Qirui Sun and Jianliang Sun.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eYuan Cheng\u0026nbsp;is mainly responsible for the paper or experimental design, paper revision and financial support. The first draft of the manuscript was written by Jiating Cheng and\u0026nbsp;Weiping Lei\u0026nbsp;and all authors commented on previous versions of the manuscript. Corresponding author\u0026nbsp;Yuan Cheng and Weiping Lei\u0026nbsp;contributed equally to this work.\u0026nbsp;All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank Hangzhou First People\u0026rsquo;s Hospital for providing a platform for clinical trials. At the same time, we would also like to thank all the medical staff of the Department of Anesthesiology of Hangzhou First People\u0026rsquo;s Hospital for their help and guidance for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eDepartment of Anesthesiology, Sir Run Run Shaw Hospital College of Medicine Zhejiang University, Hangzhou 3100016 China.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003eDepartment of Anesthesiology, Affiliated Hangzhou First People\u0026apos;s Hospital, School of Medicine, Westlake University, Hangzhou 310006, China.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eEvered L, Silbert B, Knopman DS et al. Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018. Br J Anaesth 2018; 121:1005-1012.\u003c/li\u003e\n\u003cli\u003eCizmeci EA, Slooter AJC. Defining perioperative neurocognitive disorders: still more to clarify. Br J Anaesth 2019; 123:e468.\u003c/li\u003e\n\u003cli\u003eMoller JT, Cluitmans P, Rasmussen LS et al. Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet 1998; 351:857-861.\u003c/li\u003e\n\u003cli\u003eTasbihgou SR, Absalom AR. Postoperative neurocognitive disorders. Korean J Anesthesiol 2021; 74:15-22.\u003c/li\u003e\n\u003cli\u003eShoair OA, Grasso Ii MP, Lahaye LA et al. Incidence and risk factors for postoperative cognitive dysfunction in older adults undergoing major noncardiac surgery: A prospective study. J Anaesthesiol Clin Pharmacol 2015; 31:30-36.\u003c/li\u003e\n\u003cli\u003eZhang Y, Bao HG, Lv YL et al. Risk factors for early postoperative cognitive dysfunction after colorectal surgery. BMC Anesthesiol 2019; 19:6.\u003c/li\u003e\n\u003cli\u003eKapoor MC. Neurological dysfunction after cardiac surgery and cardiac intensive care admission: A narrative review part 2: Cognitive dysfunction after critical illness; potential contributors in surgery and intensive care; pathogenesis; and therapies to prevent/treat perioperative neurological dysfunction. Ann Card Anaesth 2020; 23:391-400.\u003c/li\u003e\n\u003cli\u003eXie G, Zhang W, Chang Y, Chu Q. Relationship between perioperative inflammatory response and postoperative cognitive dysfunction in the elderly. Med Hypotheses 2009; 73:402-403.\u003c/li\u003e\n\u003cli\u003ePetersen RH, Holbek BL, Hansen HJ, Kehlet H. Video-assisted thoracoscopic surgery-taking a step into the future. Eur J Cardiothorac Surg 2017; 51:694-695.\u003c/li\u003e\n\u003cli\u003eChen X, Liu Q, Fan L. Effects of thoracic paravertebral block combined with s-ketamine on postoperative pain and cognitive function after thoracoscopic surgery. Heliyon 2022; 8.\u003c/li\u003e\n\u003cli\u003eBlanco R, Parras T, McDonnell JG, Prats-Galino A. Serratus plane block: a novel ultrasound-guided thoracic wall nerve block. Anaesthesia 2013; 68:1107-1113.\u003c/li\u003e\n\u003cli\u003eMayes J, Davison E, Panahi P et al. An anatomical evaluation of the serratus anterior plane block. Anaesthesia 2016; 71:1064-1069.\u003c/li\u003e\n\u003cli\u003eXie C, Ran G, Chen D, Lu Y. A narrative review of ultrasound-guided serratus anterior plane block. Annals of Palliative Medicine 2021; 10:700-706.\u003c/li\u003e\n\u003cli\u003eQiu Y WJ, Huang Q, et al. Acute pain after serratus anterior plane or thoracic paravertebral blocks for video-assisted thoracoscopic surgery: A randomised trial. Retraction. European journal of anaesthesiology 2020; 37:624.\u003c/li\u003e\n\u003cli\u003eDe Cassai A, Boscolo A, Zarantonello F et al. Serratus anterior plane block for video-assisted thoracoscopic surgery: A meta-analysis of randomised controlled trials. Eur J [14]Anaesthesiol 2021; 38:106-114.\u003c/li\u003e\n\u003cli\u003eZhang X, Zhang C, Zhou X et al. Analgesic Effectiveness of Perioperative Ultrasound-Guided Serratus Anterior Plane Block Combined with General Anesthesia in Patients Undergoing Video-Assisted Thoracoscopic Surgery: A Systematic Review and Meta-analysis. Pain Med 2020; 21:2412-2422.\u003c/li\u003e\n\u003cli\u003eKelliher LJS, Scott M. Modifying the Stress Response \u0026ndash; Perioperative Considerations and Controversies. Anesthesiology Clinics 2022; 40:23-33.\u003c/li\u003e\n\u003cli\u003eJiang L, Dong R, Xu M et al. Inhibition of the integrated stress response reverses oxidative stress damage-induced postoperative cognitive dysfunction. Front Cell Neurosci 2022; 16:992869.\u003c/li\u003e\n\u003cli\u003e[19Jung SM, Cho CK. The effects of deep and light propofol anesthesia on stress response in patients undergoing open lung surgery: a randomized controlled trial. Korean J Anesthesiol 2015; 68:224-231.\u003c/li\u003e\n\u003cli\u003eEvered LA, Silbert BS. Postoperative Cognitive Dysfunction and Noncardiac Surgery. Anesth Analg 2018; 127:496-505.\u003c/li\u003e\n\u003cli\u003eLanga KM, Levine DA. The diagnosis and management of mild cognitive impairment: a clinical review. JAMA 2014; 312:2551-2561.\u003c/li\u003e\n\u003cli\u003eSerrano CM, Sorbara M, Minond A et al. Validation of the Argentine version of the Montreal Cognitive Assessment Test (MoCA): A screening tool for Mild Cognitive Impairment and Mild Dementia in Elderly. Dementia \u0026amp; Neuropsychologia 2020; 14:145-152.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cdiv class=\"gridtable\"\u003e\n \u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eDemographic data\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal (n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB (n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 (40%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16 (53%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" rowspan=\"2\"\u003e\n \u003cp\u003e0.301\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18 (60%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14 (47%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge(years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68.57\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e68.43\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.931\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\n \u003cp\u003eSurgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWedge resection\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18 (60%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16 (63%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" rowspan=\"4\"\u003e\n \u003cp\u003e0.652\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLobectomy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10 (33%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 (37%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLung puncture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThoracotomy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (6.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"6\"\u003e\n \u003cp\u003eEducation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGrade school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 (23%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" rowspan=\"6\"\u003e\n \u003cp\u003e0.822\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eJunior high school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11 (37%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13 (43%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSenior high school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (20%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eVocational school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (6.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eJunior college\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (10%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of drug use in the tracheal extubation period\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnalgesic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSufentanil(5\u0026micro;g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2(6.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSufentanil(10\u0026micro;g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4(13.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.565\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFlurbiprofenaxetil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3(10%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOther\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDexmedetomidine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2(6.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2(6.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eneostigmine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.659\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eatropine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003epropofol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of mean arterial pressure (MAP)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e105.02\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e112.66\u0026thinsp;\u0026plusmn;\u0026thinsp;2.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" rowspan=\"6\"\u003e\n \u003cp\u003e0.223\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e86.47\u0026thinsp;\u0026plusmn;\u0026thinsp;2.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e102.03\u0026thinsp;\u0026plusmn;\u0026thinsp;4.40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e91.63\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e87.03\u0026thinsp;\u0026plusmn;\u0026thinsp;2.86\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e82.40\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e78.76\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e81.04\u0026thinsp;\u0026plusmn;\u0026thinsp;1.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e80.00\u0026thinsp;\u0026plusmn;\u0026thinsp;2.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.28\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.93\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of heart rate (HR)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e69.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79.23\u0026thinsp;\u0026plusmn;\u0026thinsp;2.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" rowspan=\"6\"\u003e\n \u003cp\u003e0.403\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e75.23\u0026thinsp;\u0026plusmn;\u0026thinsp;2.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e78.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.72\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e70.70\u0026thinsp;\u0026plusmn;\u0026thinsp;2.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e68.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e68.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e64.63\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e64.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e66.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e77.47\u0026thinsp;\u0026plusmn;\u0026thinsp;2.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79.13\u0026thinsp;\u0026plusmn;\u0026thinsp;2.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ctable id=\"Tab5\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of oxygen saturation (SpO\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e96.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e95.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" rowspan=\"6\"\u003e\n \u003cp\u003e0.197\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e97.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e97.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e99.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e98.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e97.73\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ctable id=\"Tab6\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of end-tidal pressure of carbon dioxide (P\u003csub\u003eET\u003c/sub\u003eCO\u003csub\u003e2\u003c/sub\u003e)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e37.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e38.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\n \u003cp\u003e0.936\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e38.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e38.50\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e39.23\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e38.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e39.53\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e39.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003ctable id=\"Tab7\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of depth of anesthesia (BIS)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e94.40\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e93.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" rowspan=\"6\"\u003e\n \u003cp\u003e0.511\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e48.60\u0026thinsp;\u0026plusmn;\u0026thinsp;2.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e47.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e47.67\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e47.17\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e48.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e45.50\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e52.20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e53.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eT5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e79.27\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e77.90\u0026thinsp;\u0026plusmn;\u0026thinsp;3.11\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ctable id=\"Tab8\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eComparison of intraoperative arterial blood gas indexes\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLocal(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDSPB(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePCO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e191.4\u0026thinsp;\u0026plusmn;\u0026thinsp;98.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e197.13\u0026thinsp;\u0026plusmn;\u0026thinsp;112.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.117\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTCO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e29.31\u0026thinsp;\u0026plusmn;\u0026thinsp;2.26 \u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e27.71\u0026thinsp;\u0026plusmn;\u0026thinsp;3.49 \u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHCO\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e27.65\u0026thinsp;\u0026plusmn;\u0026thinsp;2.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e26.63\u0026thinsp;\u0026plusmn;\u0026thinsp;2.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.084\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGlu\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.62\u0026thinsp;\u0026plusmn;\u0026thinsp;1.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.105\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLac\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.53\u0026thinsp;\u0026plusmn;\u0026thinsp;2.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.445\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eK\u003csup\u003e+\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e3.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.334\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBEecf\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.29\u0026thinsp;\u0026plusmn;\u0026thinsp;3.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.105\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003eThere were no significant differences in sex, age, type of surgery, or educational level, as shown in Table 1.\u003c/p\u003e\n\u003cp\u003eThere were no significant differences in drug use during tracheal extubation, as shown in Table 2.\u003c/p\u003e\n\u003cp\u003eThere were no significant differences in MAP (P=0.223), HR (P=0.403), SpO\u003csub\u003e2\u003c/sub\u003e (P=0.197),\u0026nbsp;P\u003csub\u003eET\u003c/sub\u003eCO\u003csub\u003e2\u003c/sub\u003e (P=0.936), or BIS (P=0.511), as shown and Tables 3\u0026ndash;7\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere was no significant difference in the intraoperative blood gas analysis between the two groups, except for TCO2 (P \u0026lt; 0.05)( Table 8).\u003c/p\u003e\n\u003cp\u003eT0 .(Entering the operating room); T1（After tracheal intubation); T2（the thoracoscope enters through the incision）; T3( One hour after the nerve block);T4(At the end of surgery); T5(30 minutes after surgery).\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"perioperative neurocognitive disorder, thoracic surgery, general anesthesia, deep serratus anterior plane block (DSPB), elderly patients","lastPublishedDoi":"10.21203/rs.3.rs-3936426/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3936426/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eTo evaluate and compare the effects of a modified deep serratus anterior plane block (DSPB) combined with general anesthesia on surgical stress and perioperative neurocognitive disorder (PND) in elderly patients undergoing thoracic surgery, providing a new way to reduce the occurrence of PND in elderly patients undergoing thoracic surgery.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eSixty-six patients undergoing thoracic surgery were randomly assigned to receive either single-shot DSPB or local block after tracheal intubation using ropivacaine 0.5% 20 mL. The primary outcomes were the visual analog scale (VAS) score at each time point and the Montreal cognitive assessment (MoCA) score before surgery and after discharge from the hospital (or seventh day postoperative). Secondary outcomes included drug consumption, vital signs, blood gas analysis, malondialdehyde, superoxide dismutase, and serum cortisol levels.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eSixty patients were eventually enrolled in this study. The VAS scores were significantly lower in the DSPB group than in the local block group (all P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The difference in blood gas analysis index TCO2 (27.71\u0026thinsp;\u0026plusmn;\u0026thinsp;3.49 vs 29.31\u0026thinsp;\u0026plusmn;\u0026thinsp;2.26) in the two groups was statistically significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The length of hospitalization in the DSPB group was shorter than that in the local block group (6.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35 vs 7.20\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49), and the difference was statistically significant (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). There were no statistically significant differences in MoCA scores before surgery and after hospitalization (or the seventh day postoperative), stress indices, vital signs, bispectral index value, blood gas analysis (except TCO\u003csub\u003e2\u003c/sub\u003e), and drug addiction during extubation at each time point (all P\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eCompared with local block, DSPB provided a superior analgesic effect with a lower VAS score and shorter length of hospitalization in elderly ptalatients undergoing thoracic surgery. It does not require ultrasound equipment, making it simpler and easier to operate, and is especially suitable for widespread implementation in grassroots hospitals.\u003c/p\u003e","manuscriptTitle":"The effects of modified deep serratus anterior plane block on surgical stress and perioperative neurocognitive disorders in elderly patients undergoing thoracic surgery: a randomized clinical study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-04 19:05:12","doi":"10.21203/rs.3.rs-3936426/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"350e4a69-950e-473c-b209-f2bc3af96f48","owner":[],"postedDate":"March 4th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-05-21T05:21:06+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-04 19:05:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3936426","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3936426","identity":"rs-3936426","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}