The Impact of Different Inspired Oxygen Concentrations Combined with Nebulized Prostaglandin E1 on Oxygenation in Patients Undergoing One- Lung Ventilation

The Impact of Different Inspired Oxygen Concentrations Combined with Nebulized Prostaglandin E1 on Oxygenation in Patients Undergoing One- Lung Ventilation | 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 Impact of Different Inspired Oxygen Concentrations Combined with Nebulized Prostaglandin E1 on Oxygenation in Patients Undergoing One- Lung Ventilation Lingxi Xing, Paerhati Halisa, Yuyan Ding, Yihu Zhou, Jiaqi chang, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5849993/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: One-lung ventilation (OLV) requires a high inspired oxygen concentration (FiO 2 ) to promote oxygenation improvement, yet it increases the risk of postoperative pulmonary complications. Therefore, this study aimed to investigate the effects of prostaglandin E 1 (PGE 1 ) in reducing FiO 2 during general anesthesia and mechanical ventilation on oxygenation and postoperative complications in patients undergoing OLV. Method: A total of 120 patients scheduled for elective left thoracotomy esophageal cancer surgery were randomly divided into four groups (n = 30): Group L (FiO 2 = 0.4, PGE 1 = 0.1μg /kg), Group M (FiO 2 = 0.5, PGE 1 = 0.1μg /kg), Group H (FiO 2 = 0.6, PGE 1 = 0.1μg /kg), and Group C (FiO 2 = 0.4, normal saline solution). The primary outcome was oxygenation during OLV. Secondary outcomes included intrapulmonary shunt (Qs/Qt), incidence of postoperative pulmonary complications, and changes in inflammatory cytokines. Results: Group H exhibited higher PaO 2 values than Groups L, M, and C at all time points T1-T6. Group M also showed higher PaO 2 values than Groups L and C at all time points T1-T6. In contrast, Group L demonstrated significantly higher PaO 2 values than Group C at time points T2-T4. The nebulization groups (L, M, H) had significantly higher PaO 2 /FiO 2 than Group C at time points T2-T4. Group H had higher Qs/Qt values than Groups L, M, and C at all time points T1-T6. At time points T2-T4, Group L had significantly lower Qs/Qt values compared to both Group C and Group M, which in turn had significantly lower values than Group C. Regarding interleukin-6 (IL-6) levels, Group C was significantly higher than the nebulization groups at time points T5-T8, while Group L was significantly lower than Groups M and H at T8. In terms of tumor necrosis factor-α(TNF-α) levels, Group C was significantly higher than the nebulization groups at time points T7-T8. With respect to clinical pulmonary infection score (CPIS), Group L was significantly lower than Groups M, H, and C. There was no statistically significant difference in the overall incidence of postoperative complications probability (PPCs) among the four groups, nor were there statistically significant differences in pneumothorax, pulmonary infection, anastomotic leakage, ICU stay duration, or total hospital stay duration among the groups. Conclusion: PGE 1 demonstrates a significant advantage in reducing the incidence of hypoxemia, effectively improving oxygenation status in patients undergoing OLV with lower FiO 2 . Given the effects of PGE 1 on oxygenation and inflammatory factors, as well as the CPIS, the results of this study suggest that a clinical regimen of 0.4 FiO 2 + 0.1μg /kg PGE 1 is appropriate. Trial registration: registry: www.chictr.org.cn registration number: ChiCTR1800018288 Prostaglandin E1 One-lung ventilation inspired oxygen concentration Figures Figure 1 Figure 2 Figure 3 Background One-lung ventilation (OLV) is widely employed in the anesthesia process for thoracic surgery. During OLV, the ventilation-receiving lung exhibits reduced compliance due to the gravitational influence of the mediastinum and the elevated diaphragm in the lateral decubitus position. Meanwhile, although the non-ventilated lung remains unventilated, certain blood perfusion increases intrapulmonary shunt (Qs/Qt). These factors may augment the risk of intraoperative hypoxemia in patients. Therefore, during OLV, pure oxygen or high inspired oxygen concentration (FiO 2 ) are typically used to maintain patient oxygenation [ 1 ] . Current lung-protective ventilation strategies recommend reducing the FiO 2 as much as possible while ensuring adequate oxygenation, although the specific concentration remains undefined [ 2 ] . Prostaglandin E 1 (PGE 1 ), a selective pulmonary artery dilator, has been previously shown to effectively reduce Qs/Qt and significantly improve oxygenation when nebulized and inhaled into the ventilated lung prior to OLV, with minimal impact on hemodynamics [ 3 ] . This study aims to investigate the effects of PGE 1 on lowering the FiO 2 during general anesthesia and mechanical ventilation on oxygenation and postoperative complications in patients undergoing OLV. Methods Study population A total of 120 patients with esophageal cancer scheduled for radical resection at the Affiliated Cancer Hospital of Nanjing Medical University were enrolled. Pathology confirmed esophageal cancer diagnoses. All participating patients or their families provided informed consent. Study subjects included 120 patients scheduled for left thoracotomy esophageal cancer radical surgery, aged 18–79 years, with a BMI of 18–29.9 kg/m² and ASA physical status II or III. Exclusion criteria included: (1) history of pulmonary surgery, immunotherapy, or neoadjuvant chemotherapy; (2) preoperative severe dysfunction of the heart, liver, or kidneys; (3) severe complications such as hypertension, coronary heart disease, or glaucoma. Patients were excluded for: (1) withdrawal from the study at any stage; (2) severe arrhythmia or circulatory instability during surgery; (3) surgery less than 2 or more than 6 hours; (4) SpO 2 < 90% during surgery failing to rise to ≥ 90% within 3 minutes or further decrease to < 88%. All patients were randomly assigned to 1 of 4 groups using a random number table: Group L (FiO 2 = 0.4, PGE 1 = 0.1µg /kg), Group M (FiO 2 = 0.5, PGE 1 = 0.1µg /kg), Group H (FiO 2 = 0.6, PGE 1 = 0.1µg /kg), or Group C (FiO 2 = 0.4, normal saline solution). All subjects enrolled provided written informed consent, and the study was approved by the Ethics Committee of Nanjing Medical University. Anesthesia and intervention All patients underwent ultrasound-guided right internal jugular vein catheterization and right radial artery catheterization under local anesthesia for pressure monitoring upon arrival in the operating room. Total intravenous anesthesia was administered without premedication. The anesthesia induction sequence included midazolam 0.05 mg·kg⁻¹, fentanyl 3–4 µg·kg⁻¹, propofol 1 mg·kg⁻¹, and cisatracurium 0.2 mg·kg⁻¹. After 3 minutes of oxygen desaturation, a left double-lumen endobronchial tube was inserted under video laryngoscopy, with its position confirmed using a fiberoptic bronchoscope. Volume-controlled mechanical ventilation (VCV) was employed, with the anesthesia machine settings configured as follows: tidal volume (VT) 6–8 ml/kg (ideal body weight), PEEP 5 cmH₂O, respiratory rate 12–14 breaths per minute, inspiratory-to-expiratory ratio 1:2. The RR was adjusted to maintain end-tidal CO₂ (ETCO₂) between 35–45 cmH₂O, and FiO₂ was set according to the respective study group. If SpO₂ dropped below 90% during one-lung ventilation (OLV) and persisted for more than 3 minutes or further decreased to less than 88%, the following interventions were sequentially applied: increasing FiO₂ to 100%, applying continuous positive airway pressure (CPAP) to the non-ventilated lung, and if necessary, restoring two-lung ventilation. During the maintenance phase of anesthesia, intravenous infusion of propofol at a rate of 0.04–0.06 mg·kg⁻¹·min⁻¹, remifentanil at 0.2 µg·kg⁻¹·min⁻¹, cisatracurium at 0.15 mg·kg⁻¹·h⁻¹, and dexmedetomidine at 0.2 µg·kg⁻¹·h⁻¹ was administered. Intraoperative warming was maintained using an inflatable warming blanket to ensure nasopharyngeal temperature remained above 36 ℃. Blood pressure fluctuations were kept within 20% of the baseline value, with vasoactive drugs used as necessary to regulate blood pressure. After stable anesthesia, the patient was positioned in the right lateral decubitus position, and a fiberoptic bronchoscope was used to confirm the correct placement of the double-lumen tube. Nebulization was then initiated, with Group L, M, and H receiving PGE 1 nebulization (0.1 µg/kg diluted in 10 ml of normal saline) to the right lung, while Group C received ultrasonic nebulization of 10 ml of normal saline to the right lung. The nebulization flow rate was set at 2 L/min, and the nebulization duration was 10 minutes to ensure complete nebulization of all fluids. After the onset of OLV, the VT was adjusted to 4–6 ml/kg (ideal body weight), while other respiratory parameters remained unchanged. During chest closure, manual lung recruitment was performed to restore two-lung ventilation (with airway pressure limited to below 30 cmH₂O for 30 seconds), and all patients were transferred to the ICU at the end of the surgery. Observed indicators The surgical duration, OLV duration, blood loss, urine output, and fluid intake of patients were recorded. Blood samples were collected from the radial artery and the right internal jugular vein for blood gas analysis at the following time points: before anesthesia induction (T0), post-anesthesia/pre-nebulization (T1), OLV 10 min (T2), OLV 15 min (T3), OLV 30 min (T4), OLV 60 min (T5), and OLV 120 min (T6). The following parameters were recorded at each time point: PaO 2 , SaO 2 , PaCO 2 , PvO 2 , SvO 2 , and the Qs/Qt, which was calculated using the formula: Qs/Qt= (CcO 2 − CaO 2 )/ (CcO 2 − CvO 2 ), where CaO 2 = (1.36 ∗ Hb ∗ SaO 2 )+ (0.0031 ∗ PaO 2 ), CvO 2 = (1.36 ∗ Hb ∗ SvO 2 ) + (0.0031 ∗ PvO 2 ), and CcO 2 = [FiO 2 ∗ (P B − P H2O ) − PaCO 2 / R] ∗ 0.0031 + (1.36 ∗ Hb), with P B = 760 mmHg, P H2O = 47 mmHg, and R = 0.8. Additionally, the ETCO 2 , MAP, Ppeak, HR and PaO 2 /FiO 2 at each time point were recorded. Central venous blood samples were collected at T0, T5, T7 (30 min after two-lung ventilation), and T8 (24h post-surgery). The concentrations of serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured using the ELISA method. The clinical pulmonary infection score (CPIS) on post-operative day 2, ICU stay duration, total hospital stay, and pulmonary complications within the first seven post-operative days were also recorded. Statistical analysis Using PASS 2021, the sample size was calculated based on the PaO 2 values of each group at 30 minutes of OLV during the pilot study. With α = 0.05 and 1-β = 0.9, at least 24 patients per group were required to achieve a power of 0.8 and a two-sided alpha level of 0.05. Considering a 20% dropout rate, a total of 30 patients were ultimately included in each group. The analysis was conducted using SPSS27.0 software. Normally distributed quantitative data are expressed as mean ± standard deviation (M ± SD). Between-group comparisons were performed using one-way ANOVA, while within-group comparisons were conducted using repeated measures ANOVA. Categorical data are presented as cases (%) and compared between groups using the χ² test. A P-value < 0.05 was considered statistically significant. Outcomes The primary outcome was oxygenation during one lung ventilation (OLV), including PaO 2 measured at T2–T6. Secondary outcomes included Qs/Qt and PaO 2 /FiO 2 during OLV, IL-6 and TNF-α levels at T1, T2, T7, and T8, CPIS, postoperative complications probability (PPCs), intensive care unit (ICU) stay duration, and total hospitalization time. Results Baseline characteristics This study included 120 patients (88 males, 23 females), mean age 63.46 ± 6.26 years, randomly assigned to four groups. Six cases of hypoxemia occurred in Group C, one in Group L. Seven patients were excluded, resulting in a final sample of 113 patients. There were no statistically significant differences in gender, age, ASA classification, BMI, preoperative PaO 2 , surgery duration, or OLV duration among the four groups (Table 1). Table 1 Characteristic of patients with esophageal cancer (Mean ± SD) Characteristic L group(n = 29) M group(n = 30) H group(n = 30) C group(n = 24) Male/Female 22/7 25/5 23/7 19/5 Age (year) 63.3 ± 6.5 63.2 ± 5.4 62.8 ± 6.8 64.5 ± 7.6 ASA (Ⅱ/Ⅲ) 22/7 24/6 21/9 20/4 BMI (kg/m 2 ) 22.9 ± 2.8 23.6 ± 2.6 23.3 ± 3.2 22.4 ± 2.8 Preoperative PaO 2 (mmHg) 80.1 ± 8.0 81.4 ± 7.5 78.4 ± 10.4 79.3 ± 9.5 Duration of surgery (min) 214.3 ± 45.9 215.2 ± 46.8 208.9 ± 58.9 210.0 ± 54.6 Duration of OLV (min) 177.3 ± 44.2 172.1 ± 46.6 171.3 ± 46.3 175.8 ± 47.6 BMI, Body mass index; OLV, one-lung ventilation L, 0.4 FiO2 + 0.1µg/kg PGE1; M, 0.5 FiO2 + 0.1µg/kg PGE1;H, 0.6 FiO2 + 0.2µg/kg PGE1;C, 0.4 FiO2 + normal saline solution Effects of PGE on oxygenation under different FiO levels Within the first 30 minutes after the start of OLV, PaO 2 and PaO 2 /FiO 2 decreased rapidly, while Qs/Qt gradually increased. PaO 2 and PaO 2 /FiO 2 reached their lowest points at 60 minutes of OLV in the nebulized groups L, M and H, whereas the lowest point in the control group C occurred at 30 minutes (Figs. 1,2,3). Qs/Qt peaked at 60 minutes of OLV in the nebulized groups L, M and H, but peaked at 30 minutes in the control group C (Table 2, Figs. 1, 3). Throughout OLV, PaO 2 in the H group was higher than that in the groups L, M, and C at all time points. PaO 2 in the group M was higher than that in the groups L and C at all time points. PaO 2 in the group L was significantly higher than that in the group L between T2 and T4. (Table 2, Figs. 1). The PaO 2 /FiO 2 in the nebulized groups L, M and H was significantly higher than that in the group C between T2 and T4(Table 2, Figs. 2). Qs/Qt in the group H was higher than that in the groups L, M, and C at all time points. Between T2 and T4, Qs/Qt in the group L was significantly lower than that in the groups C and M, and Qs/Qt in the group M was significantly lower than that in the group C (Table 2, Figs. 3). Effects of PGE 1 on inflammatory factors and postoperative pulmonary complications under different FiO 2 levels Regarding IL-6 levels, the group C showed significantly higher levels at T5, T7, and T8 compared to the nebulized groups L, M and H (Table 3). At T8, IL-6 levels in the group L were significantly lower than those in the groups M and H, with no statistical differences at other time points. Regarding TNF-α levels, the group C exhibited significantly higher levels at T7 and T8 compared to the nebulized groups L, M and H, while there were no statistical differences among the groups L, M, and H. In terms of postoperative CPIS, the group L had significantly lower scores than the groups M, H, and C. There were no statistically significant differences in the overall incidence of PPCs among the four groups, nor were there differences in atelectasis, pulmonary infections, anastomotic leaks, ICU stay duration, or total hospital stay among the groups. Table 2 The levels of PaO 2 、OI、Qs/Qt among four groups Indicator Group T 1 T 2 T 3 T 4 T 5 T 6 PaO 2 ,mmHg L 172.7 ± 51.1 100.4 ± 25.6 a 90.2 ± 29.4 a 85.7 ± 15.3 a 79.8 ± 16.9 100.5 ± 24.6 M 242.5 ± 41.2 ab 129.5 ± 56.5 ab 111.5 ± 30.4 ab 105.8 ± 28.3 ab 100.8 ± 38.0 ab 115.6 ± 32.6 ab H 273.4 ± 32.4 abc 151.4 ± 34.2 abc 134.4 ± 29.4 abc 124.2 ± 24.1 abc 116.4 ± 33.5 abc 152.8 ± 46.2 abc C 177.3 ± 51.5 82.4 ± 24.0 76.7 ± 13.0 71.6 ± 12.5 79.5 ± 14.7 101.9 ± 24.3 PaO 2 /FiO 2 , mmHg L 434.8 ± 122.2 250.0 ± 63.9 a 225.4 ± 73104.4 a 201.8 ± 33.5 a 199.5 ± 42.3 246.6 ± 60.2 M 481.7 ± 89.2 254.5 ± 55.8 a 221.6 ± 72.3 a 210.8 ± 54.6 a 202.7 ± 73.0 231.7 ± 65.5 H 454.3 ± 61.3 253.3 ± 52.68 a 219.6 ± 45.4 a 200.6 ± 45.5 a 192.4 ± 58.3 253.6 ± 77.8 C 443.3 ± 128.7 205.9 ± 60.1 191.8 ± 32.7 178.9 ± 31.2 198.7 ± 36.7 254.8 ± 60.7 Qs/Qt L 7.50 ± 2.3 12.8 ± 1.7 a 13.5 ± 2.0 a 14.4 ± 1.6 a 15.8 ± 2.0 14.4 ± 2.7 M 8.4 ± 2.4 14.4 ± 2.4 ab 15.4 ± 1.8 ab 15.6 ± 1.3 ab 16.0 ± 1.5 15.2 ± 1.6 H 11.7 ± 1.5 abc 16.6 ± 1.6 abc 17.6 ± 1.4 abc 18.8 ± 1.2 abc 19.3 ± 1.2 abc 17.5 ± 1.4 abc C 8.0 ± 2.6 15.5 ± 2.7 16.2 ± 2.9 17.1 ± 2.7 16.3 ± 2.1 15.5 ± 1.9 a P<0.05 compared with Group C; b P<0.05 compared with Group L, c P<0.05 compared with Group M Table 3 The levels of SaO 2 、PaCO 2 、ETCO 2 、Ppeak、MAP、HR among four groups Indicator Group T 1 T 2 T 3 T 4 T 5 T 6 SaO 2 , % L 99.2 ± 0.8 95.3 ± 2.4 95.2 ± 2.7 93.5 ± 3.2 95.1 ± 2.0 97.3 ± 1.6 M 99.9 ± 0.4 96.9 ± 2.7 ab 96.4 ± 2.5 ab 95.9 ± 3.0 ab 96.2 ± 2.9 ab 97.6 ± 2.1 H 100 ± 0.0 98.7 ± 1.0 abc 98.3 ± 1.4 abc 98.3 ± 1.4 abc 98.0 ± 1.3 abc 98.8 ± 1.5 ab C 99.3 ± 0.3 95.4 ± 1.1 95.5 ± 2.2 93.0 ± 3.1 95.4 ± 2.1 97.3 ± 1.6 PaCO 2 , mmHg L 46.2 ± 18.1 46.3 ± 7.2 43.8 ± 4.9 42.5 ± 5.2 40.9 ± 6.1 39.4 ± 4.7 M 40.6 ± 3.2 41.1 ± 5.7 39.4 ± 5.6 40.1 ± 6.1 42.2 ± 6.2 38.4 ± 5.7 H 42.9 ± 6.0 43.3 ± 6.2 41.8 ± 5.8 40.1 ± 5.8 41.6 ± 6.3 39.5 ± 6.8 C 42.5 ± 4.4 41.5 ± 5.9 41.3 ± 5.3 41.3 ± 5.8 40.4 ± 6.3 39.7 ± 5.4 ETCO 2 , mmHg L 35.2 ± 3.6 36.3 ± 4.7 35.6 ± 4.0 33.9 ± 4.6 33.1 ± 4.4 33.6 ± 3.3 M 34.5 ± 3.8 38.1 ± 3.6 36.7 ± 3.6 36.5 ± 4.2 36.4 ± 4.5 36.3 ± 4.9 H 35.4 ± 5.8 36.8 ± 4.6 35.7 ± 4.1 34.7 ± 4.0 35.1 ± 4.4 34.4 ± 4.4 C 35.6 ± 5.3 36.6 ± 4.2 36.0 ± 4.1 35.3 ± 3.6 35.4 ± 3.8 34.1 ± 4.0 Ppeak, cmH 2 O L 15.1 ± 3.7 21.9 ± 4.9 21.4 ± 4.9 22.1 ± 5.9 21.8 ± 4.9 22.0 ± 3.5 M 14.9 ± 3.2 22.5 ± 3.7 23.0 ± 3.4 23.6 ± 4.5 24.3 ± 4.5 24.3 ± 3.9 H 14.9 ± 3.2 22.5 ± 3.7 23.0 ± 3.4 23.6 ± 4.5 24.3 ± 4.5 24.3 ± 3.9 C 14.4 ± 2.6 23.1 ± 3.9 23.2 ± 3.4 23.7 ± 3,9 24.6 ± 3.8 24.9 ± 4.5 MAP, mmHg L 97.6 ± 13.1 98.1 ± 13.0 94.2 ± 13.4 96.7 ± 11.2 100.4 ± 10.2 98.8 ± 12.1 M 97.6 ± 13.1 98.1 ± 13.0 94.2 ± 13.4 96.7 ± 11.2 100.4 ± 10.2 98.8 ± 12.1 H 102.2 ± 14.6 96.6 ± 16.0 92.7 ± 16.2 94.2 ± 22.8 95.7 ± 21.2 95.4 ± 16.4 C 98.4 ± 12.2 98.3 ± 13.1 92.8 ± 12.8 98.2 ± 11.1 100.9 ± 9.8 98.3 ± 12.9 HR, bpm L 82.7 ± 13.6 78.3 ± 15.7 75.6 ± 13.7 78.3 ± 13.9 78.8 ± 14.1 76.4 ± 12.4 M 74.0 ± 10.0 73.9 ± 14.8 73.7 ± 13.0 72.1 ± 12.8 71.8 ± 11.6 70.0 ± 11.2 H 76.6 ± 14.5 73.7 ± 14.7 74.4 ± 14.4 82.7 ± 12.7 78.8 ± 13.6 75.9 ± 13.9 C 77.1 ± 10.5 74.2 ± 14.3 75.7 ± 13.1 77.7 ± 9.8 79.0 ± 13.4 74.3 ± 10.7 a P<0.05 compared with Group C; b P<0.05 compared with Group L, c P<0.05 compared with Group M Table 3 Serum levels of IL-6 and TNF-αin the four groups Biomarkers Group T 1 T 5 T 7 T 8 IL-6, pg/mL L 4.96 ± 2.49 23.86 ± 4.97 a 39.53 ± 6.84 a 58.54 ± 15.41 a M 4.95 ± 2.43 23.82 ± 5.15 a 39.65 ± 6.61 a 67.69 ± 9.17 ab H 5.15 ± 2.76 23.78 ± 4.51 a 38.45 ± 10.59 a 67.97 ± 7.22 ab C 4.14 ± 2.57 34.80 ± 7.35 84.4 ± 15.72 109.63 ± 17.47 TNF-α, pg/mL L 0.82 ± 0.23 1.88 ± 0.4 2.66 ± 0.45 a 3.3 ± 0.86 a M 0.86 ± 0.41 1.74 ± 0.52 2.49 ± 0.54 a 3.09 ± 0.50 a H 1.00 ± 0.40 1.87 ± 0.91 2.68 ± 0.70 a 3.02 ± 0.65 a C 1.00 ± 0.29 1.77 ± 0.83 3.53 ± 0.79 4.63 ± 0.71 a P<0.05 compared with Group C; b P<0.05 compared with Group L. T1 (post-anesthesia/pre-nebulization), T5 (OLV 60 min), T7 (30 min after two-lung ventilation), and T8 (24h post-surgery). Table 5 Postoperative rehabilitation of patients in the four groups Characteristics L M H C 29 30 30 24 CPIS 1.8 ± 0.9 3.4 ± 1.2 b 3.9 ± 1.8 b 4.43 ± 1.3 b Atelectasis of lung [n(%)] 0(0) 1(3.33) 2(6.67) 0 (0) Pulmonary infection [n(%)] 1(3.45) 1(3.33) 2(6.67) 1(4.55) Anastomotic leakage [n(%)] 1(3.45) 1(3.33) 1(3.33) 2 (9.10) LOS in hospital, day 1.1 ± 1.2 1.0 ± 0.0 1.0 ± 0.0 1.3 ± 0.6 LOS in ICU, day 25.5 ± 7.8 23.2 ± 7.0 20.4 ± 2.4 27.3 ± 8.2 b P<0.05 compared with Group L Discussion During OLV, the core elements of anesthesia management include adequate oxygenation and lung protection. Effectively reducing the risk of hypoxemia during OLV and minimizing oxidative stress damage caused by high FiO 2 are two critical yet seemingly contradictory aspects of lung protection research during OLV [ 4 , 5 ] . Regarding the appropriate level of FiO 2 during OLV, clear clinical guidelines are currently lacking. When performing OLV, a protective ventilation strategy should strictly control FiO 2 . While ensuring adequate oxygenation, efforts should be made to maintain FiO 2 at the lowest possible level. FiO 2 reduction should start from a baseline below 1.0 to mitigate oxidative stress damage exacerbated by high-concentration oxygen inhalation [ 5 ] . Studies have indicated [ 6 ] that inhaling high FiO 2 during general anesthesia has adverse effects on the human body, and it is recommended to use ventilation with FiO 2 not exceeding 0.6. Additionally, ROCCA reported [ 7 ] that the minimum FiO 2 during OLV can be as low as 0.4. Therefore, the FiO 2 values set in this study were 0.4, 0.5, and 0.6. Previous studies have reported that [ 3 ] PGE 1 can help maintain adequate oxygenation in OLV patients with FiO 2 0.6, but it remains unclear how low an FiO 2 PGE 1 can help OLV patients tolerate. Therefore, this study aimed to investigate the effects of different FiO 2 levels on oxygenation and Qs/Qt in OLV patients after pre-OLV nebulized inhalation of 0.1 µg/kg PGE 1 in the ventilated lung, to determine the optimal FiO 2 value. Yang M et al. [ 8 ] reported that during OLV, 58% of patients undergoing protective strategies (FiO 2 = 0.5, PEEP = 5 cmH 2 O, VT = 6 mL/kg) experienced hypoxemia (SpO 2 95%. Similarly, this study observed that in the group C with FiO 2 0.4, 6 patients developed hypoxemia (SpO 2 dropped below 90% and failed to recover to ≥ 90% within 3 minutes or further decreased to < 88%), with an incidence rate of 25%, indicating a higher risk of hypoxemia in patients with FiO 2 0.4. In the group L, which received FiO 2 0.4 with PGE 1 nebulization, only one case of hypoxemia occurred, indicating that nebulized PGE 1 can significantly reduce the incidence of hypoxemia. This also demonstrates that under FiO 2 0.4 during OLV, nebulized PGE 1 in the ventilated lung can ensure adequate oxygen supply, thereby enabling a reduction in FiO 2 while maintaining oxygenation. Furthermore, in OLV patients receiving nebulized PGE 1 , although PaO 2 and SaO 2 levels decreased when FiO 2 was reduced from 0.6 to 0.4, they remained within safe ranges. Additionally, we observed no significant differences in PaCO 2 , ETCO 2 , Ppeak, MAP, or HR levels among patients under FiO 2 0.6, 0.5, and 0.4. Therefore, nebulized 0.1 µg/kg PGE 1 in the ventilated lung enables OLV patients to safely tolerate FiO 2 0.4. During OLV, the patient's physiological state undergoes the following changes: First, the non-ventilated lung fully collapses, receiving no ventilation but retaining some blood perfusion, resulting in Qs/Qt. Second, due to gravitational effects, the ventilated lung takes on most of the pulmonary blood flow and all the ventilation, leading to an imbalance in the ventilation-perfusion ratio (V/Q). Additionally, when the patient is in the lateral decubitus position, the compliance of the ventilated lung decreases due to the gravitational effect of the mediastinum and the elevation of the diaphragm. Finally, the non-ventilated lung undergoes hypoxic pulmonary vasoconstriction (HPV).During OLV, HPV serves as one of the body's self-regulatory protective mechanisms against hypoxia [ 9 ] and is particularly critical. The primary stimulus for this mechanism is alveolar oxygen tension, which induces pre-capillary vasoconstriction to reduce blood flow to hypoxic lung tissue. This reduces Qs/Qt, mitigates V/Q mismatch, and improves oxygenation. Under the influence of HPV, blood flow in hypoxic regions of the lung can be redirected to non-hypoxic areas, with a redistribution rate of up to 50%-70% [ 10 ] . This mechanism plays a crucial role in reducing Qs/Qt, adjusting the V/Q, and improving oxygenation. Studies indicate that under normal HPV function, blood perfusion in the non-ventilated lung can be reduced to 20%-25% [ 11 ] . Further studies reveal the HPV effect becomes evident within 15 minutes of OLV, peaks at 60 minutes, and shows no significant changes thereafter [ 12 – 14 ] . In clinical practice, studies indicate [ 15 ] the Qs/Qt rises rapidly during the initial stage of OLV, reaching its peak at 30 minutes, accompanied by a rapid decline in arterial PaO 2 , particularly between 15 and 30 minutes of OLV when PaO 2 drops to its lowest level. Subsequently, over the next 1–2 hours, PaO 2 gradually rises. In this study, we found PaO 2 in all four groups decreased linearly within 30 minutes of OLV, with the group C reaching its lowest point at 30 minutes, and then gradually rising. This finding is consistent with previous research. After PGE 1 nebulization, the L, M, and H groups' lowest PaO 2 values were delayed until 60 minutes, when the HPV effect peaked. Therefore, pre-OLV ventilation-side lung nebulization with PGE 1 helps patients pass through the sharp decline in PaO 2 during the first 30 minutes of OLV, reducing hypoxemia occurrence. Previous studies have demonstrated [ 9 , 16 ] that HPV can improve the body's oxygenation function by reducing Qs/Qt. However, it is important to note that this regulatory effect of HPV is influenced by various factors, including anesthetic drugs, disease conditions, surgical procedures, and physiological factors [ 17 ] , with FiO 2 being one important factor. This study found that from anesthesia induction to OLV 30 minutes, Qs/Qt in the L, M, and H groups increased in a dose-dependent manner with increasing FiO 2 , which may be related to enhanced inhibition of HPV as FiO 2 increases [ 18 ] . In addition, during the first 30 minutes after the start of OLV, Qs/Qt in the group L was significantly lower than in the group C. We speculate that the mechanism by which PGE 1 inhalation reduces Qs/Qt is mainly related to PGE 1 being a selective pulmonary artery vasodilator [ 19 ] . PGE 1 increases blood flow to the ventilated side of the lung, thereby reducing Qs/Qt. Intravenous infusion of PGE 1 can reduce serum IL-6 and TNF-α levels, thereby alleviating organ inflammatory damage [ 20 ] . This study further observed the effect of inhaled PGE 1 on serum inflammatory factors. The results showed that inhalation of 0.1µg/kg PGE 1 significantly reduced serum IL-6 levels at 30 minutes after OLV, 30 minutes after OLV completion, and 24 hours postoperatively, as well as serum TNF-α levels at 30 minutes after OLV completion and 24 hours postoperatively. Notably, IL-6 in the group L on the second postoperative day was also significantly lower than in the groups M and H. IL-6, as a pro-inflammatory factor with diverse biological functions, plays a crucial role in immune regulation and inflammatory responses in various pathophysiological processes. During the acute phase of injury and infection, the concentration of IL-6 in the blood typically increases significantly [ 21 ] . Breunig et al. [ 22 ] found that IL-6 levels in both serum and bronchoalveolar lavage fluid significantly increased after the completion of OLV. TNF-α is one of the pro-inflammatory factors involved in mediating acute lung injury, with functions such as inducing pulmonary endothelial cell activation, leukocyte migration, granulocyte degranulation, and capillary leakage. In addition, it can directly or indirectly inhibit the synthesis of pulmonary surfactant [ 23 , 24 ] . Additionally, it is noteworthy that the CPIS in the L group was significantly lower than in the other three groups. CPIS is an assessment tool that integrates clinical manifestations, imaging features, and microbiological test results to evaluate the severity of pulmonary infection. However, due to the limited sample size, there were no statistically significant differences among the four groups in terms of postoperative atelectasis incidence, pulmonary infection incidence, anastomotic leak incidence, ICU stay duration, and total hospital stay. Taking into account the effects of the aforementioned inflammatory factors and the comprehensive evaluation of postoperative CPIS, it is recommended to utilize 0.4 FiO 2 + 0.1µg/kg PGE 1 as a superior nebulization combination. This combination not only ensures adequate oxygenation for the body, reduces Qs/Qt, and lowers the incidence of hypoxemia, but also shows promise in reducing the infection risk observed at the time points we monitored. Limitation However, several limitations of this study cannot be overlooked. Firstly, the sample size calculation was based on PaO 2 as the primary outcome measure rather than postoperative complications, which may lead to false-negative conclusions regarding the incidence of postoperative complications. Secondly, the nebulized dose of PGE 1 was set at 0.1µg/kg, and higher doses of PGE 1 were not investigated. Lastly, our study population was limited to patients with normal lung function, and subjects with impaired lung function were not included. Therefore, whether the recommended combination (0.4 FiO 2 + 0.1µg/kg PGE 1 ) is suitable for patients with impaired lung function, the elderly, or obese individuals remains to be further validated. Conclusion In summary, administering 0.1µg/kg PGE 1 to the ventilated side lung prior to OLV reduces the Qs/Qt, improves oxygenation, decreases the incidence of hypoxemia, and contributes to lower levels of inflammatory cytokines IL-6 and TNF-αduring surgery, resulting in a lower CPIS. Declarations Ethics approval and consent to participate All experiments were performed in accordance with relevant international and local guidelines and regulations. The study protocol was approved by the Ethics Committee of Nanjing Medical University. Informed consent was obtained from all participants prior to conducting any study-related procedures. 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 that they have no competing interests. Funding Excellent Project of Jiangsu Cancer Hospital (YC201805) Authors' contributions Lingxi Xing and Paerhati Halisa were responsible for data collection as well as writing the article. Yuyan Ding was responsible for data analysis and writing of the manuscript. Yihu Zhou and Jiaqi chang was responsible for the statistical analysis. Xiaolan Gu and Lianbing Gu was responsible for guiding and reviewing the revision. All authors reviewed the manuscript. Acknowledgements Not applicable References COHEN E. Recommendations for airway control and difficult airway management in thoracic anesthesia and lung separation procedures. Are we ready for the challenge? [J]. Minerva Anestesiol. 2009;75(1–2):3–5. ŞENTüRK M, SLINGER P. Intraoperative mechanical ventilation strategies for one-lung ventilation [J]. Best Pract Res Clin Anaesthesiol. 2015;29(3):357–69. LI P, GU L, BIAN Q, et al. Effects of prostaglandin E(1) nebulization of ventilated lung under 60%O(2) one lung ventilation on patients' oxygenation and oxidative stress: a randomised controlled trial [J]. Respir Res. 2020;21(1):113. BLANK RS, COLQUHOUN D A, DURIEUX M E, et al. Management of One-lung Ventilation: Impact of Tidal Volume on Complications after Thoracic Surgery [J]. Anesthesiology. 2016;124(6):1286–95. OKAHARA S, SHIMIZU K, SUZUKI S, et al. Associations between intraoperative ventilator settings during one-lung ventilation and postoperative pulmonary complications: a prospective observational study [J]. BMC Anesthesiol. 2018;18(1):13. MEYHOFF C S, WETTERSLEV J, JORGENSEN L N, et al. Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after abdominal surgery: the PROXI randomized clinical trial [J]. JAMA. 2009;302(14):1543–50. DELLA ROCCA G COCCIAC. Ventilatory management of one-lung ventilation [J]. Minerva Anestesiol. 2011;77(5):534–6. YANG M, AHN H J, KIM K, et al. Does a protective ventilation strategy reduce the risk of pulmonary complications after lung cancer surgery? a randomized controlled trial [J]. Chest. 2011;139(3):530–7. LUMB A B SLINGERP. Hypoxic pulmonary vasoconstriction: physiology and anesthetic implications [J]. Anesthesiology. 2015;122(4):932–46. BENUMOF JL. Isoflurane anesthesia and arterial oxygenation during one-lung ventilation [J]. Anesthesiology. 1986;64(4):419–22. DOMINO K B BOROWECL, ALEXANDER C M, et al. Influence of isoflurane on hypoxic pulmonary vasoconstriction in dogs [J]. Anesthesiology. 1986;64(4):423–9. BENUMOF JL. Intermittent hypoxia increases lobar hypoxic pulmonary vasoconstriction [J]. Anesthesiology. 1983;58(5):399–404. LOHSER J. Lung Injury After One-Lung Ventilation: A Review of the Pathophysiologic Mechanisms Affecting the Ventilated and the Collapsed Lung [J]. Anesth Analg. 2015;121(2):302–18. BURROWES K S, CLARK A R, WILSHER M L, et al. Hypoxic pulmonary vasoconstriction as a contributor to response in acute pulmonary embolism [J]. Ann Biomed Eng. 2014;42(8):1631–43. CHIGURUPATI K, RAMAN S P, PAPPU U K, et al. Effectiveness of ventilation of nondependent lung for a brief period in improving arterial oxygenation during one-lung ventilation: A prospective study [J]. Ann Card Anaesth. 2017;20(1):72–5. KARZAI W. Hypoxemia during one-lung ventilation: prediction, prevention, and treatment [J]. Anesthesiology. 2009;110(6):1402–11. SZEGEDI, L L, D'HOLLANDER A A, VERMASSEN F E, et al. Gravity is an important determinant of oxygenation during one-lung ventilation [J]. Acta Anaesthesiol Scand. 2010;54(6):744–50. DUNHAM-SNARY K J WUD, SYKES E A, et al. Hypoxic Pulmonary Vasoconstriction: From Molecular Mechanisms to Medicine [J]. Chest. 2017;151(1):181–92. DELLA ROCCA G, COCCIA C. Inhaled aerosolized prostaglandin E1, pulmonary hemodynamics, and oxygenation during lung transplantation [J]. Minerva Anestesiol. 2008;74(11):627–33. FARROKHNIA E, MAKAREM J, KHAN Z H, et al. The effects of prostaglandin E1 on interleukin-6, pulmonary function and postoperative recovery in oesophagectomised patients [J]. Anaesth Intensive Care. 2009;37(6):937–43. BIRUKOVA A A, TIAN Y, MELITON A, et al. Stimulation of Rho signaling by pathologic mechanical stretch is a second hit to Rho-independent lung injury induced by IL-6 [J]. Am J Physiol Lung Cell Mol Physiol. 2012;302(9):L965–75. BREUNIG A, GAMBAZZI F, BECK-SCHIMMER B, et al. Cytokine & chemokine response in the lungs, pleural fluid and serum in thoracic surgery using one-lung ventilation [J]. J Inflamm (Lond). 2011;8:32. LI F, GAO J, SOKOLOVE J, et al. Polymorphisms in the TNF-α, TNFR1 gene and risk of rheumatoid arthritis in Chinese Han population [J]. Int J Immunogenet. 2014;41(6):499–502. GARCIA-VERDUGO I, GARCIA DE PACO E, ESPINASSOUS Q, et al. Synthetic peptides representing the N-terminal segment of surfactant protein C modulate LPS-stimulated TNF-alpha production by macrophages [J]. Innate Immun. 2009;15(1):53–62. Additional Declarations No competing interests reported. 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-5849993","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":409060711,"identity":"73507208-2d43-4d6f-ba21-6615250c6856","order_by":0,"name":"Lingxi Xing","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Lingxi","middleName":"","lastName":"Xing","suffix":""},{"id":409060712,"identity":"1401debf-a3c5-4220-b1e6-ceaa617ca1f9","order_by":1,"name":"Paerhati Halisa","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Paerhati","middleName":"","lastName":"Halisa","suffix":""},{"id":409060713,"identity":"cc3bdaa0-b49c-4291-8010-be04264b0e42","order_by":2,"name":"Yuyan Ding","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Yuyan","middleName":"","lastName":"Ding","suffix":""},{"id":409060714,"identity":"7e868ff2-8a78-4ee5-83f1-ba869da37340","order_by":3,"name":"Yihu Zhou","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Yihu","middleName":"","lastName":"Zhou","suffix":""},{"id":409060715,"identity":"ab968258-90dc-434e-b689-5246b5a02254","order_by":4,"name":"Jiaqi chang","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Jiaqi","middleName":"","lastName":"chang","suffix":""},{"id":409060716,"identity":"053db446-6249-4cb5-868e-57f8ee83d471","order_by":5,"name":"Xiaolan Gu","email":"","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":false,"prefix":"","firstName":"Xiaolan","middleName":"","lastName":"Gu","suffix":""},{"id":409060717,"identity":"4a68d636-5eb3-4c2f-b53c-9f2851b42f51","order_by":6,"name":"Lianbing Gu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIie3RsUoDQRCA4TkOJs2Raycg5ytMdZK3mSWylaKVbhEwENkUnqTVt7jSMhJYm9X6yjsEa20knaaPZM8uxX71/MwsCxBFBwjz+cunGLxZDmaqFTMNJ0NyGlo/TB6r1Tu33oWTAs7KpLNFUj+oj1F3m/Y4DHzZKlumnK21UTOEfHEn+5PUXrO8aTwZWN2opyMg/1oHtqxrkiuXjSu/TTwC03koESbBH+Lm4vtS2bRPclqSWGRuREO/hNyExaOMqtWExLss+Jbj5fy52xiUfPuVXxszLfLF/f5kR/a/8SiKouhPv9TBT4VYiz3fAAAAAElFTkSuQmCC","orcid":"","institution":"The Affiliated Cancer Hospital of Nanjing Medical University \u0026 Jiangsu Cancer Hospital \u0026 Jiangsu Institute of Cancer Research","correspondingAuthor":true,"prefix":"","firstName":"Lianbing","middleName":"","lastName":"Gu","suffix":""}],"badges":[],"createdAt":"2025-01-17 14:38:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5849993/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5849993/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":75591751,"identity":"1c19c766-c387-4e47-99b9-fee61f979b7a","added_by":"auto","created_at":"2025-02-06 07:12:52","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":67681,"visible":true,"origin":"","legend":"\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eP＜0.05 compared with Group C;\u003csup\u003e b\u003c/sup\u003eP＜0.05 compared with Group L，\u003csup\u003ec\u003c/sup\u003eP＜0.05 compared with Group M\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5849993/v1/d952cfe6bbb28f2204a24095.png"},{"id":75592363,"identity":"1c4dbe37-2e65-4a1b-9134-bb205553e161","added_by":"auto","created_at":"2025-02-06 07:20:52","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":61153,"visible":true,"origin":"","legend":"\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eP＜0.05 compared with Group C;\u003csup\u003e b\u003c/sup\u003eP＜0.05 compared with Group L，\u003csup\u003ec\u003c/sup\u003eP＜0.05 compared with Group M\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-5849993/v1/3a9ebacfcaf551347743bbc5.png"},{"id":75591756,"identity":"96e1343d-8aee-4974-aa02-10c5e61eaa29","added_by":"auto","created_at":"2025-02-06 07:12:52","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":59477,"visible":true,"origin":"","legend":"\u003cp\u003e\u003csup\u003ea\u003c/sup\u003eP＜0.05 compared with Group C;\u003csup\u003e b\u003c/sup\u003eP＜0.05 compared with Group L，\u003csup\u003ec\u003c/sup\u003eP＜0.05 compared with Group M\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-5849993/v1/4e0e08e397b5a1744153536d.png"},{"id":75738080,"identity":"3b7917f1-07a7-4994-9d89-ffe248abe714","added_by":"auto","created_at":"2025-02-07 15:53:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1188455,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5849993/v1/d451a574-ba78-4699-a5c7-1256443a86f6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Different Inspired Oxygen Concentrations Combined with Nebulized Prostaglandin E1 on Oxygenation in Patients Undergoing One- Lung Ventilation","fulltext":[{"header":"Background","content":"\u003cp\u003eOne-lung ventilation (OLV) is widely employed in the anesthesia process for thoracic surgery. During OLV, the ventilation-receiving lung exhibits reduced compliance due to the gravitational influence of the mediastinum and the elevated diaphragm in the lateral decubitus position. Meanwhile, although the non-ventilated lung remains unventilated, certain blood perfusion increases intrapulmonary shunt (Qs/Qt). These factors may augment the risk of intraoperative hypoxemia in patients. Therefore, during OLV, pure oxygen or high inspired oxygen concentration (FiO\u003csub\u003e2\u003c/sub\u003e) are typically used to maintain patient oxygenation\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. Current lung-protective ventilation strategies recommend reducing the FiO\u003csub\u003e2\u003c/sub\u003e as much as possible while ensuring adequate oxygenation, although the specific concentration remains undefined \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eProstaglandin E\u003csub\u003e1\u003c/sub\u003e (PGE\u003csub\u003e1\u003c/sub\u003e), a selective pulmonary artery dilator, has been previously shown to effectively reduce Qs/Qt and significantly improve oxygenation when nebulized and inhaled into the ventilated lung prior to OLV, with minimal impact on hemodynamics\u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. This study aims to investigate the effects of PGE\u003csub\u003e1\u003c/sub\u003e on lowering the FiO\u003csub\u003e2\u003c/sub\u003e during general anesthesia and mechanical ventilation on oxygenation and postoperative complications in patients undergoing OLV.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy population\u003c/h2\u003e \u003cp\u003eA total of 120 patients with esophageal cancer scheduled for radical resection at the Affiliated Cancer Hospital of Nanjing Medical University were enrolled. Pathology confirmed esophageal cancer diagnoses. All participating patients or their families provided informed consent. Study subjects included 120 patients scheduled for left thoracotomy esophageal cancer radical surgery, aged 18\u0026ndash;79 years, with a BMI of 18\u0026ndash;29.9 kg/m\u0026sup2; and ASA physical status II or III. Exclusion criteria included: (1) history of pulmonary surgery, immunotherapy, or neoadjuvant chemotherapy; (2) preoperative severe dysfunction of the heart, liver, or kidneys; (3) severe complications such as hypertension, coronary heart disease, or glaucoma. Patients were excluded for: (1) withdrawal from the study at any stage; (2) severe arrhythmia or circulatory instability during surgery; (3) surgery less than 2 or more than 6 hours; (4) SpO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;\u0026lt;\u0026thinsp;90% during surgery failing to rise to \u0026ge;\u0026thinsp;90% within 3 minutes or further decrease to \u0026lt;\u0026thinsp;88%. All patients were randomly assigned to 1 of 4 groups using a random number table: Group L (FiO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.4, PGE\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.1\u0026micro;g /kg), Group M (FiO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.5, PGE\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.1\u0026micro;g /kg), Group H (FiO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.6, PGE\u003csub\u003e1\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.1\u0026micro;g /kg), or Group C (FiO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;0.4, normal saline solution). All subjects enrolled provided written informed consent, and the study was approved by the Ethics Committee of Nanjing Medical University.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eAnesthesia and intervention\u003c/h3\u003e\n\u003cp\u003eAll patients underwent ultrasound-guided right internal jugular vein catheterization and right radial artery catheterization under local anesthesia for pressure monitoring upon arrival in the operating room. Total intravenous anesthesia was administered without premedication. The anesthesia induction sequence included midazolam 0.05 mg\u0026middot;kg⁻\u0026sup1;, fentanyl 3\u0026ndash;4 \u0026micro;g\u0026middot;kg⁻\u0026sup1;, propofol 1 mg\u0026middot;kg⁻\u0026sup1;, and cisatracurium 0.2 mg\u0026middot;kg⁻\u0026sup1;. After 3 minutes of oxygen desaturation, a left double-lumen endobronchial tube was inserted under video laryngoscopy, with its position confirmed using a fiberoptic bronchoscope. Volume-controlled mechanical ventilation (VCV) was employed, with the anesthesia machine settings configured as follows: tidal volume (VT) 6\u0026ndash;8 ml/kg (ideal body weight), PEEP 5 cmH₂O, respiratory rate 12\u0026ndash;14 breaths per minute, inspiratory-to-expiratory ratio 1:2. The RR was adjusted to maintain end-tidal CO₂ (ETCO₂) between 35\u0026ndash;45 cmH₂O, and FiO₂ was set according to the respective study group. If SpO₂ dropped below 90% during one-lung ventilation (OLV) and persisted for more than 3 minutes or further decreased to less than 88%, the following interventions were sequentially applied: increasing FiO₂ to 100%, applying continuous positive airway pressure (CPAP) to the non-ventilated lung, and if necessary, restoring two-lung ventilation. During the maintenance phase of anesthesia, intravenous infusion of propofol at a rate of 0.04\u0026ndash;0.06 mg\u0026middot;kg⁻\u0026sup1;\u0026middot;min⁻\u0026sup1;, remifentanil at 0.2 \u0026micro;g\u0026middot;kg⁻\u0026sup1;\u0026middot;min⁻\u0026sup1;, cisatracurium at 0.15 mg\u0026middot;kg⁻\u0026sup1;\u0026middot;h⁻\u0026sup1;, and dexmedetomidine at 0.2 \u0026micro;g\u0026middot;kg⁻\u0026sup1;\u0026middot;h⁻\u0026sup1; was administered. Intraoperative warming was maintained using an inflatable warming blanket to ensure nasopharyngeal temperature remained above 36 ℃. Blood pressure fluctuations were kept within 20% of the baseline value, with vasoactive drugs used as necessary to regulate blood pressure. After stable anesthesia, the patient was positioned in the right lateral decubitus position, and a fiberoptic bronchoscope was used to confirm the correct placement of the double-lumen tube. Nebulization was then initiated, with Group L, M, and H receiving PGE\u003csub\u003e1\u003c/sub\u003e nebulization (0.1 \u0026micro;g/kg diluted in 10 ml of normal saline) to the right lung, while Group C received ultrasonic nebulization of 10 ml of normal saline to the right lung. The nebulization flow rate was set at 2 L/min, and the nebulization duration was 10 minutes to ensure complete nebulization of all fluids. After the onset of OLV, the VT was adjusted to 4\u0026ndash;6 ml/kg (ideal body weight), while other respiratory parameters remained unchanged. During chest closure, manual lung recruitment was performed to restore two-lung ventilation (with airway pressure limited to below 30 cmH₂O for 30 seconds), and all patients were transferred to the ICU at the end of the surgery.\u003c/p\u003e\n\u003ch3\u003eObserved indicators\u003c/h3\u003e\n\u003cp\u003eThe surgical duration, OLV duration, blood loss, urine output, and fluid intake of patients were recorded. Blood samples were collected from the radial artery and the right internal jugular vein for blood gas analysis at the following time points: before anesthesia induction (T0), post-anesthesia/pre-nebulization (T1), OLV 10 min (T2), OLV 15 min (T3), OLV 30 min (T4), OLV 60 min (T5), and OLV 120 min (T6). The following parameters were recorded at each time point: PaO\u003csub\u003e2\u003c/sub\u003e, SaO\u003csub\u003e2\u003c/sub\u003e, PaCO\u003csub\u003e2\u003c/sub\u003e, PvO\u003csub\u003e2\u003c/sub\u003e, SvO\u003csub\u003e2\u003c/sub\u003e, and the Qs/Qt, which was calculated using the formula: Qs/Qt= (CcO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;\u0026minus;\u0026thinsp;CaO\u003csub\u003e2\u003c/sub\u003e)/ (CcO\u003csub\u003e2\u003c/sub\u003e\u0026thinsp;\u0026minus;\u0026thinsp;CvO\u003csub\u003e2\u003c/sub\u003e), where CaO\u003csub\u003e2\u003c/sub\u003e= (1.36 \u0026lowast; Hb \u0026lowast; SaO\u003csub\u003e2\u003c/sub\u003e)+ (0.0031 \u0026lowast; PaO\u003csub\u003e2\u003c/sub\u003e), CvO\u003csub\u003e2\u003c/sub\u003e= (1.36 \u0026lowast; Hb \u0026lowast; SvO\u003csub\u003e2\u003c/sub\u003e) + (0.0031 \u0026lowast; PvO\u003csub\u003e2\u003c/sub\u003e), and CcO\u003csub\u003e2\u003c/sub\u003e= [FiO\u003csub\u003e2\u003c/sub\u003e \u0026lowast; (P\u003csub\u003eB\u003c/sub\u003e\u0026minus; P\u003csub\u003eH2O\u003c/sub\u003e)\u0026thinsp;\u0026minus;\u0026thinsp;PaCO\u003csub\u003e2\u003c/sub\u003e / R] \u0026lowast; 0.0031 + (1.36 \u0026lowast; Hb), with P\u003csub\u003eB\u003c/sub\u003e= 760 mmHg, P\u003csub\u003eH2O\u003c/sub\u003e= 47 mmHg, and R\u0026thinsp;=\u0026thinsp;0.8. Additionally, the ETCO\u003csub\u003e2\u003c/sub\u003e, MAP, Ppeak, HR and PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e at each time point were recorded.\u003c/p\u003e \u003cp\u003eCentral venous blood samples were collected at T0, T5, T7 (30 min after two-lung ventilation), and T8 (24h post-surgery). The concentrations of serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured using the ELISA method. The clinical pulmonary infection score (CPIS) on post-operative day 2, ICU stay duration, total hospital stay, and pulmonary complications within the first seven post-operative days were also recorded.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eUsing PASS 2021, the sample size was calculated based on the PaO\u003csub\u003e2\u003c/sub\u003e values of each group at 30 minutes of OLV during the pilot study. With α\u0026thinsp;=\u0026thinsp;0.05 and 1-β\u0026thinsp;=\u0026thinsp;0.9, at least 24 patients per group were required to achieve a power of 0.8 and a two-sided alpha level of 0.05. Considering a 20% dropout rate, a total of 30 patients were ultimately included in each group. The analysis was conducted using SPSS27.0 software. Normally distributed quantitative data are expressed as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (M\u0026thinsp;\u0026plusmn;\u0026thinsp;SD). Between-group comparisons were performed using one-way ANOVA, while within-group comparisons were conducted using repeated measures ANOVA. Categorical data are presented as cases (%) and compared between groups using the χ\u0026sup2; test. A P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eOutcomes\u003c/h3\u003e\n\u003cp\u003eThe primary outcome was oxygenation during one lung ventilation (OLV), including PaO\u003csub\u003e2\u003c/sub\u003e measured at T2\u0026ndash;T6. Secondary outcomes included Qs/Qt and PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e during OLV, IL-6 and TNF-α levels at T1, T2, T7, and T8, CPIS, postoperative complications probability (PPCs), intensive care unit (ICU) stay duration, and total hospitalization time.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003eBaseline characteristics\u003c/h2\u003e\n \u003cp\u003eThis study included 120 patients (88 males, 23 females), mean age 63.46\u0026thinsp;\u0026plusmn;\u0026thinsp;6.26 years, randomly assigned to four groups. Six cases of hypoxemia occurred in Group C, one in Group L. Seven patients were excluded, resulting in a final sample of 113 patients. There were no statistically significant differences in gender, age, ASA classification, BMI, preoperative PaO\u003csub\u003e2\u003c/sub\u003e, surgery duration, or OLV duration among the four groups (Table 1). \u0026nbsp;\u003c/p\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\u003eCharacteristic of patients with esophageal cancer (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristic\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eL group(n\u0026thinsp;=\u0026thinsp;29)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eM group(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eH group(n\u0026thinsp;=\u0026thinsp;30)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eC group(n\u0026thinsp;=\u0026thinsp;24)\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\u003eMale/Female\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25/5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19/5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (year)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e63.3\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e63.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e62.8\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e64.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eASA (Ⅱ/Ⅲ)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24/6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21/9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20/4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePreoperative PaO\u003csub\u003e2\u003c/sub\u003e (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e80.1\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e81.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e78.4\u0026thinsp;\u0026plusmn;\u0026thinsp;10.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e79.3\u0026thinsp;\u0026plusmn;\u0026thinsp;9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuration of surgery (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e214.3\u0026thinsp;\u0026plusmn;\u0026thinsp;45.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e215.2\u0026thinsp;\u0026plusmn;\u0026thinsp;46.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e208.9\u0026thinsp;\u0026plusmn;\u0026thinsp;58.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e210.0\u0026thinsp;\u0026plusmn;\u0026thinsp;54.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDuration of OLV (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e177.3\u0026thinsp;\u0026plusmn;\u0026thinsp;44.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e172.1\u0026thinsp;\u0026plusmn;\u0026thinsp;46.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e171.3\u0026thinsp;\u0026plusmn;\u0026thinsp;46.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e175.8\u0026thinsp;\u0026plusmn;\u0026thinsp;47.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003eBMI, Body mass index; OLV, one-lung ventilation\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003eL, 0.4 FiO2\u0026thinsp;+\u0026thinsp;0.1\u0026micro;g/kg PGE1; M, 0.5 FiO2\u0026thinsp;+\u0026thinsp;0.1\u0026micro;g/kg PGE1;H, 0.6 FiO2\u0026thinsp;+\u0026thinsp;0.2\u0026micro;g/kg PGE1;C, 0.4 FiO2\u0026thinsp;+\u0026thinsp;normal saline solution\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eEffects of PGE on oxygenation under different FiO levels\u003c/h3\u003e\n\u003cp\u003eWithin the first 30 minutes after the start of OLV, PaO\u003csub\u003e2\u003c/sub\u003e and PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e decreased rapidly, while Qs/Qt gradually increased. PaO\u003csub\u003e2\u003c/sub\u003e and PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e reached their lowest points at 60 minutes of OLV in the nebulized groups L, M and H, whereas the lowest point in the control group C occurred at 30 minutes (Figs. 1,2,3). Qs/Qt peaked at 60 minutes of OLV in the nebulized groups L, M and H, but peaked at 30 minutes in the control group C (Table 2, Figs. 1, 3). Throughout OLV, PaO\u003csub\u003e2\u003c/sub\u003e in the H group was higher than that in the groups L, M, and C at all time points. PaO\u003csub\u003e2\u003c/sub\u003e in the group M was higher than that in the groups L and C at all time points. PaO\u003csub\u003e2\u003c/sub\u003e in the group L was significantly higher than that in the group L between T2 and T4. (Table 2, Figs. 1). The PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e in the nebulized groups L, M and H was significantly higher than that in the group C between T2 and T4(Table 2, Figs. 2). Qs/Qt in the group H was higher than that in the groups L, M, and C at all time points. Between T2 and T4, Qs/Qt in the group L was significantly lower than that in the groups C and M, and Qs/Qt in the group M was significantly lower than that in the group C (Table 2, Figs. 3).\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eEffects of PGE\u003csub\u003e1\u003c/sub\u003e on inflammatory factors and postoperative pulmonary complications under different FiO\u003csub\u003e2\u003c/sub\u003e levels\u003c/h2\u003e\n \u003cp\u003eRegarding IL-6 levels, the group C showed significantly higher levels at T5, T7, and T8 compared to the nebulized groups L, M and H (Table\u0026nbsp;3). At T8, IL-6 levels in the group L were significantly lower than those in the groups M and H, with no statistical differences at other time points. Regarding TNF-\u0026alpha; levels, the group C exhibited significantly higher levels at T7 and T8 compared to the nebulized groups L, M and H, while there were no statistical differences among the groups L, M, and H. In terms of postoperative CPIS, the group L had significantly lower scores than the groups M, H, and C. There were no statistically significant differences in the overall incidence of PPCs among the four groups, nor were there differences in atelectasis, pulmonary infections, anastomotic leaks, ICU stay duration, or total hospital stay among the groups.\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\u0026nbsp;\u003cbr\u003e\n \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\u003eThe levels of PaO\u003csub\u003e2\u003c/sub\u003e、OI、Qs/Qt among four groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIndicator\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e1\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e6\u003c/sub\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\" colspan=\"8\"\u003e\n \u003cp\u003ePaO\u003csub\u003e2\u003c/sub\u003e,mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e172.7\u0026thinsp;\u0026plusmn;\u0026thinsp;51.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.4\u0026thinsp;\u0026plusmn;\u0026thinsp;25.6\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e90.2\u0026thinsp;\u0026plusmn;\u0026thinsp;29.4\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e85.7\u0026thinsp;\u0026plusmn;\u0026thinsp;15.3\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e79.8\u0026thinsp;\u0026plusmn;\u0026thinsp;16.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.5\u0026thinsp;\u0026plusmn;\u0026thinsp;24.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e242.5\u0026thinsp;\u0026plusmn;\u0026thinsp;41.2\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e129.5\u0026thinsp;\u0026plusmn;\u0026thinsp;56.5\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e111.5\u0026thinsp;\u0026plusmn;\u0026thinsp;30.4\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e105.8\u0026thinsp;\u0026plusmn;\u0026thinsp;28.3\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.8\u0026thinsp;\u0026plusmn;\u0026thinsp;38.0\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e115.6\u0026thinsp;\u0026plusmn;\u0026thinsp;32.6\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e273.4\u0026thinsp;\u0026plusmn;\u0026thinsp;32.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e151.4\u0026thinsp;\u0026plusmn;\u0026thinsp;34.2\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e134.4\u0026thinsp;\u0026plusmn;\u0026thinsp;29.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e124.2\u0026thinsp;\u0026plusmn;\u0026thinsp;24.1\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e116.4\u0026thinsp;\u0026plusmn;\u0026thinsp;33.5\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e152.8\u0026thinsp;\u0026plusmn;\u0026thinsp;46.2\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e177.3\u0026thinsp;\u0026plusmn;\u0026thinsp;51.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e82.4\u0026thinsp;\u0026plusmn;\u0026thinsp;24.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e76.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e71.6\u0026thinsp;\u0026plusmn;\u0026thinsp;12.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e79.5\u0026thinsp;\u0026plusmn;\u0026thinsp;14.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e101.9\u0026thinsp;\u0026plusmn;\u0026thinsp;24.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003ePaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e, mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e434.8\u0026thinsp;\u0026plusmn;\u0026thinsp;122.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e250.0\u0026thinsp;\u0026plusmn;\u0026thinsp;63.9\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e225.4\u0026thinsp;\u0026plusmn;\u0026thinsp;73104.4\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e201.8\u0026thinsp;\u0026plusmn;\u0026thinsp;33.5\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e199.5\u0026thinsp;\u0026plusmn;\u0026thinsp;42.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e246.6\u0026thinsp;\u0026plusmn;\u0026thinsp;60.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e481.7\u0026thinsp;\u0026plusmn;\u0026thinsp;89.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e254.5\u0026thinsp;\u0026plusmn;\u0026thinsp;55.8\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e221.6\u0026thinsp;\u0026plusmn;\u0026thinsp;72.3\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e210.8\u0026thinsp;\u0026plusmn;\u0026thinsp;54.6\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e202.7\u0026thinsp;\u0026plusmn;\u0026thinsp;73.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e231.7\u0026thinsp;\u0026plusmn;\u0026thinsp;65.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e454.3\u0026thinsp;\u0026plusmn;\u0026thinsp;61.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e253.3\u0026thinsp;\u0026plusmn;\u0026thinsp;52.68\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e219.6\u0026thinsp;\u0026plusmn;\u0026thinsp;45.4 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e200.6\u0026thinsp;\u0026plusmn;\u0026thinsp;45.5\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e192.4\u0026thinsp;\u0026plusmn;\u0026thinsp;58.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e253.6\u0026thinsp;\u0026plusmn;\u0026thinsp;77.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e443.3\u0026thinsp;\u0026plusmn;\u0026thinsp;128.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e205.9\u0026thinsp;\u0026plusmn;\u0026thinsp;60.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e191.8\u0026thinsp;\u0026plusmn;\u0026thinsp;32.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e178.9\u0026thinsp;\u0026plusmn;\u0026thinsp;31.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e198.7\u0026thinsp;\u0026plusmn;\u0026thinsp;36.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e254.8\u0026thinsp;\u0026plusmn;\u0026thinsp;60.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003eQs/Qt\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.50\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"8\"\u003e\u003csup\u003ea\u003c/sup\u003eP\u0026lt;0.05 compared with Group C; \u003csup\u003eb\u003c/sup\u003eP\u0026lt;0.05 compared with Group L, \u003csup\u003ec\u003c/sup\u003eP\u0026lt;0.05 compared with Group M\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\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\u003eThe levels of SaO\u003csub\u003e2\u003c/sub\u003e、PaCO\u003csub\u003e2\u003c/sub\u003e、ETCO\u003csub\u003e2\u003c/sub\u003e、Ppeak、MAP、HR among four groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIndicator\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e1\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e6\u003c/sub\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=\"5\"\u003e\n \u003cp\u003eSaO\u003csub\u003e2\u003c/sub\u003e, %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"7\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e99.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e93.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.1\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e97.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e99.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.9\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e97.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003csup\u003eabc\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e99.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e93.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e97.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003ePaCO\u003csub\u003e2\u003c/sub\u003e, mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e46.2\u0026thinsp;\u0026plusmn;\u0026thinsp;18.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e46.3\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e43.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.9\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.2\u0026thinsp;\u0026plusmn;\u0026thinsp;6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.9\u0026thinsp;\u0026plusmn;\u0026thinsp;6.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e43.3\u0026thinsp;\u0026plusmn;\u0026thinsp;6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.6\u0026thinsp;\u0026plusmn;\u0026thinsp;6.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40.4\u0026thinsp;\u0026plusmn;\u0026thinsp;6.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003eETCO\u003csub\u003e2\u003c/sub\u003e, mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.2\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.5\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.6\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e36.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35.4\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003ePpeak, cmH\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21.8\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e14.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.1\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3,9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.6\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003eMAP, mmHg\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e97.6\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.1\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e94.2\u0026thinsp;\u0026plusmn;\u0026thinsp;13.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.4\u0026thinsp;\u0026plusmn;\u0026thinsp;10.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e97.6\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.1\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e94.2\u0026thinsp;\u0026plusmn;\u0026thinsp;13.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.4\u0026thinsp;\u0026plusmn;\u0026thinsp;10.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e102.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e96.6\u0026thinsp;\u0026plusmn;\u0026thinsp;16.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e92.7\u0026thinsp;\u0026plusmn;\u0026thinsp;16.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e94.2\u0026thinsp;\u0026plusmn;\u0026thinsp;22.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.7\u0026thinsp;\u0026plusmn;\u0026thinsp;21.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e95.4\u0026thinsp;\u0026plusmn;\u0026thinsp;16.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.4\u0026thinsp;\u0026plusmn;\u0026thinsp;12.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.3\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e92.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.2\u0026thinsp;\u0026plusmn;\u0026thinsp;11.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100.9\u0026thinsp;\u0026plusmn;\u0026thinsp;9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98.3\u0026thinsp;\u0026plusmn;\u0026thinsp;12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"8\"\u003e\n \u003cp\u003eHR, bpm\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e82.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e78.3\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e75.6\u0026thinsp;\u0026plusmn;\u0026thinsp;13.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e78.3\u0026thinsp;\u0026plusmn;\u0026thinsp;13.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e78.8\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e76.4\u0026thinsp;\u0026plusmn;\u0026thinsp;12.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73.9\u0026thinsp;\u0026plusmn;\u0026thinsp;14.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e72.1\u0026thinsp;\u0026plusmn;\u0026thinsp;12.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e71.8\u0026thinsp;\u0026plusmn;\u0026thinsp;11.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e70.0\u0026thinsp;\u0026plusmn;\u0026thinsp;11.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e76.6\u0026thinsp;\u0026plusmn;\u0026thinsp;14.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73.7\u0026thinsp;\u0026plusmn;\u0026thinsp;14.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74.4\u0026thinsp;\u0026plusmn;\u0026thinsp;14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e82.7\u0026thinsp;\u0026plusmn;\u0026thinsp;12.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e78.8\u0026thinsp;\u0026plusmn;\u0026thinsp;13.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e75.9\u0026thinsp;\u0026plusmn;\u0026thinsp;13.9\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e77.1\u0026thinsp;\u0026plusmn;\u0026thinsp;10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e75.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e77.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e79.0\u0026thinsp;\u0026plusmn;\u0026thinsp;13.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74.3\u0026thinsp;\u0026plusmn;\u0026thinsp;10.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"8\"\u003e\u003csup\u003ea\u003c/sup\u003eP\u0026lt;0.05 compared with Group C; \u003csup\u003eb\u003c/sup\u003eP\u0026lt;0.05 compared with Group L, \u003csup\u003ec\u003c/sup\u003eP\u0026lt;0.05 compared with Group M\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\u0026nbsp;\u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSerum levels of IL-6 and TNF-\u0026alpha;in the four groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eBiomarkers\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e1\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e7\u003c/sub\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eT\u003csub\u003e8\u003c/sub\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=\"4\"\u003e\n \u003cp\u003eIL-6, pg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.96\u0026thinsp;\u0026plusmn;\u0026thinsp;2.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.86\u0026thinsp;\u0026plusmn;\u0026thinsp;4.97\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.53\u0026thinsp;\u0026plusmn;\u0026thinsp;6.84\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e58.54\u0026thinsp;\u0026plusmn;\u0026thinsp;15.41\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.95\u0026thinsp;\u0026plusmn;\u0026thinsp;2.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.82\u0026thinsp;\u0026plusmn;\u0026thinsp;5.15\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39.65\u0026thinsp;\u0026plusmn;\u0026thinsp;6.61\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e67.69\u0026thinsp;\u0026plusmn;\u0026thinsp;9.17\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.15\u0026thinsp;\u0026plusmn;\u0026thinsp;2.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.78\u0026thinsp;\u0026plusmn;\u0026thinsp;4.51\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38.45\u0026thinsp;\u0026plusmn;\u0026thinsp;10.59\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e67.97\u0026thinsp;\u0026plusmn;\u0026thinsp;7.22\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e4.14\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34.80\u0026thinsp;\u0026plusmn;\u0026thinsp;7.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e84.4\u0026thinsp;\u0026plusmn;\u0026thinsp;15.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e109.63\u0026thinsp;\u0026plusmn;\u0026thinsp;17.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\n \u003cp\u003eTNF-\u0026alpha;, pg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.86\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.86\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.87\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.70\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003e\u003csup\u003ea\u003c/sup\u003eP\u0026lt;0.05 compared with Group C; \u003csup\u003eb\u003c/sup\u003eP\u0026lt;0.05 compared with Group L.\u003c/p\u003e\n \u003cp\u003eT1 (post-anesthesia/pre-nebulization), T5 (OLV 60 min), T7 (30 min after two-lung ventilation), and T8 (24h post-surgery).\u003c/p\u003e\n \u003cp\u003e\u003c/p\u003e\u0026nbsp;\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\u003ePostoperative rehabilitation of patients in the four groups\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eL\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eM\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eH\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eC\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\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCPIS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e4.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAtelectasis of lung [n(%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2(6.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePulmonary infection [n(%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2(6.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1(4.55)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnastomotic leakage [n(%)]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1(3.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e2 (9.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLOS in hospital, day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e1.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLOS in ICU, day\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e23.2\u0026thinsp;\u0026plusmn;\u0026thinsp;7.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e20.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e27.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003e\u003csup\u003eb\u003c/sup\u003eP\u0026lt;0.05 compared with Group L\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003c/p\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eDuring OLV, the core elements of anesthesia management include adequate oxygenation and lung protection. Effectively reducing the risk of hypoxemia during OLV and minimizing oxidative stress damage caused by high FiO\u003csub\u003e2\u003c/sub\u003e are two critical yet seemingly contradictory aspects of lung protection research during OLV\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. Regarding the appropriate level of FiO\u003csub\u003e2\u003c/sub\u003e during OLV, clear clinical guidelines are currently lacking. When performing OLV, a protective ventilation strategy should strictly control FiO\u003csub\u003e2\u003c/sub\u003e. While ensuring adequate oxygenation, efforts should be made to maintain FiO\u003csub\u003e2\u003c/sub\u003e at the lowest possible level. FiO\u003csub\u003e2\u003c/sub\u003e reduction should start from a baseline below 1.0 to mitigate oxidative stress damage exacerbated by high-concentration oxygen inhalation\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. Studies have indicated\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e that inhaling high FiO\u003csub\u003e2\u003c/sub\u003e during general anesthesia has adverse effects on the human body, and it is recommended to use ventilation with FiO\u003csub\u003e2\u003c/sub\u003e not exceeding 0.6. Additionally, ROCCA reported\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e that the minimum FiO\u003csub\u003e2\u003c/sub\u003e during OLV can be as low as 0.4. Therefore, the FiO\u003csub\u003e2\u003c/sub\u003e values set in this study were 0.4, 0.5, and 0.6. Previous studies have reported that \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e PGE\u003csub\u003e1\u003c/sub\u003e can help maintain adequate oxygenation in OLV patients with FiO\u003csub\u003e2\u003c/sub\u003e 0.6, but it remains unclear how low an FiO\u003csub\u003e2\u003c/sub\u003e PGE\u003csub\u003e1\u003c/sub\u003e can help OLV patients tolerate. Therefore, this study aimed to investigate the effects of different FiO\u003csub\u003e2\u003c/sub\u003e levels on oxygenation and Qs/Qt in OLV patients after pre-OLV nebulized inhalation of 0.1 µg/kg PGE\u003csub\u003e1\u003c/sub\u003e in the ventilated lung, to determine the optimal FiO\u003csub\u003e2\u003c/sub\u003e value.\u003c/p\u003e \u003cp\u003eYang M et al.\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e reported that during OLV, 58% of patients undergoing protective strategies (FiO\u003csub\u003e2\u003c/sub\u003e = 0.5, PEEP = 5 cmH\u003csub\u003e2\u003c/sub\u003eO, VT = 6 mL/kg) experienced hypoxemia (SpO\u003csub\u003e2\u003c/sub\u003e \u0026lt; 95%) and required an increase in FiO\u003csub\u003e2\u003c/sub\u003e to maintain SpO\u003csub\u003e2\u003c/sub\u003e \u0026gt; 95%. Similarly, this study observed that in the group C with FiO\u003csub\u003e2\u003c/sub\u003e 0.4, 6 patients developed hypoxemia (SpO\u003csub\u003e2\u003c/sub\u003e dropped below 90% and failed to recover to ≥ 90% within 3 minutes or further decreased to \u0026lt; 88%), with an incidence rate of 25%, indicating a higher risk of hypoxemia in patients with FiO\u003csub\u003e2\u003c/sub\u003e 0.4. In the group L, which received FiO\u003csub\u003e2\u003c/sub\u003e 0.4 with PGE\u003csub\u003e1\u003c/sub\u003e nebulization, only one case of hypoxemia occurred, indicating that nebulized PGE\u003csub\u003e1\u003c/sub\u003e can significantly reduce the incidence of hypoxemia. This also demonstrates that under FiO\u003csub\u003e2\u003c/sub\u003e 0.4 during OLV, nebulized PGE\u003csub\u003e1\u003c/sub\u003e in the ventilated lung can ensure adequate oxygen supply, thereby enabling a reduction in FiO\u003csub\u003e2\u003c/sub\u003e while maintaining oxygenation. Furthermore, in OLV patients receiving nebulized PGE\u003csub\u003e1\u003c/sub\u003e, although PaO\u003csub\u003e2\u003c/sub\u003e and SaO\u003csub\u003e2\u003c/sub\u003e levels decreased when FiO\u003csub\u003e2\u003c/sub\u003e was reduced from 0.6 to 0.4, they remained within safe ranges. Additionally, we observed no significant differences in PaCO\u003csub\u003e2\u003c/sub\u003e, ETCO\u003csub\u003e2\u003c/sub\u003e, Ppeak, MAP, or HR levels among patients under FiO\u003csub\u003e2\u003c/sub\u003e 0.6, 0.5, and 0.4. Therefore, nebulized 0.1 µg/kg PGE\u003csub\u003e1\u003c/sub\u003e in the ventilated lung enables OLV patients to safely tolerate FiO\u003csub\u003e2\u003c/sub\u003e 0.4.\u003c/p\u003e \u003cp\u003eDuring OLV, the patient's physiological state undergoes the following changes: First, the non-ventilated lung fully collapses, receiving no ventilation but retaining some blood perfusion, resulting in Qs/Qt. Second, due to gravitational effects, the ventilated lung takes on most of the pulmonary blood flow and all the ventilation, leading to an imbalance in the ventilation-perfusion ratio (V/Q). Additionally, when the patient is in the lateral decubitus position, the compliance of the ventilated lung decreases due to the gravitational effect of the mediastinum and the elevation of the diaphragm. Finally, the non-ventilated lung undergoes hypoxic pulmonary vasoconstriction (HPV).During OLV, HPV serves as one of the body's self-regulatory protective mechanisms against hypoxia\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e and is particularly critical. The primary stimulus for this mechanism is alveolar oxygen tension, which induces pre-capillary vasoconstriction to reduce blood flow to hypoxic lung tissue. This reduces Qs/Qt, mitigates V/Q mismatch, and improves oxygenation. Under the influence of HPV, blood flow in hypoxic regions of the lung can be redirected to non-hypoxic areas, with a redistribution rate of up to 50%-70%\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. This mechanism plays a crucial role in reducing Qs/Qt, adjusting the V/Q, and improving oxygenation.\u003c/p\u003e \u003cp\u003eStudies indicate that under normal HPV function, blood perfusion in the non-ventilated lung can be reduced to 20%-25%\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. Further studies reveal the HPV effect becomes evident within 15 minutes of OLV, peaks at 60 minutes, and shows no significant changes thereafter\u003csup\u003e[\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e–\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. In clinical practice, studies indicate\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e the Qs/Qt rises rapidly during the initial stage of OLV, reaching its peak at 30 minutes, accompanied by a rapid decline in arterial PaO\u003csub\u003e2\u003c/sub\u003e, particularly between 15 and 30 minutes of OLV when PaO\u003csub\u003e2\u003c/sub\u003e drops to its lowest level. Subsequently, over the next 1–2 hours, PaO\u003csub\u003e2\u003c/sub\u003e gradually rises. In this study, we found PaO\u003csub\u003e2\u003c/sub\u003e in all four groups decreased linearly within 30 minutes of OLV, with the group C reaching its lowest point at 30 minutes, and then gradually rising. This finding is consistent with previous research. After PGE\u003csub\u003e1\u003c/sub\u003e nebulization, the L, M, and H groups' lowest PaO\u003csub\u003e2\u003c/sub\u003e values were delayed until 60 minutes, when the HPV effect peaked. Therefore, pre-OLV ventilation-side lung nebulization with PGE\u003csub\u003e1\u003c/sub\u003e helps patients pass through the sharp decline in PaO\u003csub\u003e2\u003c/sub\u003e during the first 30 minutes of OLV, reducing hypoxemia occurrence.\u003c/p\u003e \u003cp\u003ePrevious studies have demonstrated \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e that HPV can improve the body's oxygenation function by reducing Qs/Qt. However, it is important to note that this regulatory effect of HPV is influenced by various factors, including anesthetic drugs, disease conditions, surgical procedures, and physiological factors \u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e, with FiO\u003csub\u003e2\u003c/sub\u003e being one important factor. This study found that from anesthesia induction to OLV 30 minutes, Qs/Qt in the L, M, and H groups increased in a dose-dependent manner with increasing FiO\u003csub\u003e2\u003c/sub\u003e, which may be related to enhanced inhibition of HPV as FiO\u003csub\u003e2\u003c/sub\u003e increases\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. In addition, during the first 30 minutes after the start of OLV, Qs/Qt in the group L was significantly lower than in the group C. We speculate that the mechanism by which PGE\u003csub\u003e1\u003c/sub\u003e inhalation reduces Qs/Qt is mainly related to PGE\u003csub\u003e1\u003c/sub\u003e being a selective pulmonary artery vasodilator\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e. PGE\u003csub\u003e1\u003c/sub\u003e increases blood flow to the ventilated side of the lung, thereby reducing Qs/Qt.\u003c/p\u003e \u003cp\u003eIntravenous infusion of PGE\u003csub\u003e1\u003c/sub\u003e can reduce serum IL-6 and TNF-α levels, thereby alleviating organ inflammatory damage\u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e. This study further observed the effect of inhaled PGE\u003csub\u003e1\u003c/sub\u003e on serum inflammatory factors. The results showed that inhalation of 0.1µg/kg PGE\u003csub\u003e1\u003c/sub\u003e significantly reduced serum IL-6 levels at 30 minutes after OLV, 30 minutes after OLV completion, and 24 hours postoperatively, as well as serum TNF-α levels at 30 minutes after OLV completion and 24 hours postoperatively. Notably, IL-6 in the group L on the second postoperative day was also significantly lower than in the groups M and H. IL-6, as a pro-inflammatory factor with diverse biological functions, plays a crucial role in immune regulation and inflammatory responses in various pathophysiological processes. During the acute phase of injury and infection, the concentration of IL-6 in the blood typically increases significantly \u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. Breunig et al.\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e found that IL-6 levels in both serum and bronchoalveolar lavage fluid significantly increased after the completion of OLV. TNF-α is one of the pro-inflammatory factors involved in mediating acute lung injury, with functions such as inducing pulmonary endothelial cell activation, leukocyte migration, granulocyte degranulation, and capillary leakage. In addition, it can directly or indirectly inhibit the synthesis of pulmonary surfactant\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Additionally, it is noteworthy that the CPIS in the L group was significantly lower than in the other three groups. CPIS is an assessment tool that integrates clinical manifestations, imaging features, and microbiological test results to evaluate the severity of pulmonary infection. However, due to the limited sample size, there were no statistically significant differences among the four groups in terms of postoperative atelectasis incidence, pulmonary infection incidence, anastomotic leak incidence, ICU stay duration, and total hospital stay.\u003c/p\u003e \u003cp\u003eTaking into account the effects of the aforementioned inflammatory factors and the comprehensive evaluation of postoperative CPIS, it is recommended to utilize 0.4 FiO\u003csub\u003e2\u003c/sub\u003e + 0.1µg/kg PGE\u003csub\u003e1\u003c/sub\u003e as a superior nebulization combination. This combination not only ensures adequate oxygenation for the body, reduces Qs/Qt, and lowers the incidence of hypoxemia, but also shows promise in reducing the infection risk observed at the time points we monitored.\u003c/p\u003e "},{"header":"Limitation","content":"\u003cp\u003eHowever, several limitations of this study cannot be overlooked. Firstly, the sample size calculation was based on PaO\u003csub\u003e2\u003c/sub\u003e as the primary outcome measure rather than postoperative complications, which may lead to false-negative conclusions regarding the incidence of postoperative complications. Secondly, the nebulized dose of PGE\u003csub\u003e1\u003c/sub\u003e was set at 0.1µg/kg, and higher doses of PGE\u003csub\u003e1\u003c/sub\u003e were not investigated. Lastly, our study population was limited to patients with normal lung function, and subjects with impaired lung function were not included. Therefore, whether the recommended combination (0.4 FiO\u003csub\u003e2\u003c/sub\u003e + 0.1µg/kg PGE\u003csub\u003e1\u003c/sub\u003e) is suitable for patients with impaired lung function, the elderly, or obese individuals remains to be further validated.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, administering 0.1\u0026micro;g/kg PGE\u003csub\u003e1\u003c/sub\u003e to the ventilated side lung prior to OLV reduces the Qs/Qt, improves oxygenation, decreases the incidence of hypoxemia, and contributes to lower levels of inflammatory cytokines IL-6 and TNF-αduring surgery, resulting in a lower CPIS.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEthics approval and consent to participate\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll experiments were performed in accordance with relevant international and local guidelines and regulations. The study protocol was approved by the Ethics Committee of Nanjing Medical University. Informed consent was obtained from all participants prior to conducting any study-related procedures.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConsent for publication\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAvailability of data and materials\u003c/em\u003e\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\u003e\u003cem\u003eCompeting interests\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFunding\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eExcellent Project of Jiangsu Cancer Hospital (YC201805)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAuthors\u0026apos; contributions\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLingxi Xing and Paerhati Halisa were responsible for data collection as well as writing the article. Yuyan Ding was responsible for data analysis and writing of the manuscript. Yihu Zhou and Jiaqi chang was responsible for the statistical analysis. Xiaolan Gu and Lianbing Gu was responsible for guiding and reviewing the revision. All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAcknowledgements\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e \u003cli\u003e\u003cspan\u003eCOHEN E. Recommendations for airway control and difficult airway management in thoracic anesthesia and lung separation procedures. Are we ready for the challenge? [J]. Minerva Anestesiol. 2009;75(1\u0026ndash;2):3\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eŞENT\u0026uuml;RK M, SLINGER P. Intraoperative mechanical ventilation strategies for one-lung ventilation [J]. 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Stimulation of Rho signaling by pathologic mechanical stretch is a second hit to Rho-independent lung injury induced by IL-6 [J]. Am J Physiol Lung Cell Mol Physiol. 2012;302(9):L965\u0026ndash;75.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBREUNIG A, GAMBAZZI F, BECK-SCHIMMER B, et al. Cytokine \u0026amp; chemokine response in the lungs, pleural fluid and serum in thoracic surgery using one-lung ventilation [J]. J Inflamm (Lond). 2011;8:32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLI F, GAO J, SOKOLOVE J, et al. Polymorphisms in the TNF-α, TNFR1 gene and risk of rheumatoid arthritis in Chinese Han population [J]. Int J Immunogenet. 2014;41(6):499\u0026ndash;502.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGARCIA-VERDUGO I, GARCIA DE PACO E, ESPINASSOUS Q, et al. Synthetic peptides representing the N-terminal segment of surfactant protein C modulate LPS-stimulated TNF-alpha production by macrophages [J]. Innate Immun. 2009;15(1):53\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e\u003c/ol\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":"Prostaglandin E1, One-lung ventilation, inspired oxygen concentration","lastPublishedDoi":"10.21203/rs.3.rs-5849993/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5849993/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eOne-lung ventilation (OLV) requires a high inspired oxygen concentration (FiO\u003csub\u003e2\u003c/sub\u003e) to promote oxygenation improvement, yet it increases the risk of postoperative pulmonary complications. Therefore, this study aimed to investigate the effects of prostaglandin E\u003csub\u003e1\u003c/sub\u003e (PGE\u003csub\u003e1\u003c/sub\u003e) in reducing FiO\u003csub\u003e2\u003c/sub\u003e during general anesthesia and mechanical ventilation on oxygenation and postoperative complications in patients undergoing OLV.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethod: \u003c/strong\u003eA total of 120 patients scheduled for elective left thoracotomy esophageal cancer surgery were randomly divided into four groups (n = 30): Group L (FiO\u003csub\u003e2\u003c/sub\u003e = 0.4, PGE\u003csub\u003e1\u003c/sub\u003e = 0.1μg /kg), Group M (FiO\u003csub\u003e2\u003c/sub\u003e = 0.5, PGE\u003csub\u003e1\u003c/sub\u003e = 0.1μg /kg), Group H (FiO\u003csub\u003e2\u003c/sub\u003e = 0.6, PGE\u003csub\u003e1\u003c/sub\u003e = 0.1μg /kg), and Group C (FiO\u003csub\u003e2\u003c/sub\u003e = 0.4, normal saline solution). The primary outcome was oxygenation during OLV. Secondary outcomes included intrapulmonary shunt (Qs/Qt), incidence of postoperative pulmonary complications, and changes in inflammatory cytokines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Group H exhibited higher PaO\u003csub\u003e2\u003c/sub\u003e values than Groups L, M, and C at all time points T1-T6. Group M also showed higher PaO\u003csub\u003e2\u003c/sub\u003e values than Groups L and C at all time points T1-T6. In contrast, Group L demonstrated significantly higher PaO\u003csub\u003e2\u003c/sub\u003e values than Group C at time points T2-T4. The nebulization groups (L, M, H) had significantly higher PaO\u003csub\u003e2\u003c/sub\u003e/FiO\u003csub\u003e2\u003c/sub\u003e than Group C at time points T2-T4. Group H had higher Qs/Qt values than Groups L, M, and C at all time points T1-T6. At time points T2-T4, Group L had significantly lower Qs/Qt values compared to both Group C and Group M, which in turn had significantly lower values than Group C. Regarding interleukin-6 (IL-6) levels, Group C was significantly higher than the nebulization groups at time points T5-T8, while Group L was significantly lower than Groups M and H at T8. In terms of tumor necrosis factor-α(TNF-α) levels, Group C was significantly higher than the nebulization groups at time points T7-T8. With respect to clinical pulmonary infection score (CPIS), Group L was significantly lower than Groups M, H, and C. There was no statistically significant difference in the overall incidence of postoperative complications probability (PPCs) among the four groups, nor were there statistically significant differences in pneumothorax, pulmonary infection, anastomotic leakage, ICU stay duration, or total hospital stay duration among the groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003ePGE\u003csub\u003e1\u003c/sub\u003e demonstrates a significant advantage in reducing the incidence of hypoxemia, effectively improving oxygenation status in patients undergoing OLV with lower FiO\u003csub\u003e2\u003c/sub\u003e. Given the effects of PGE\u003csub\u003e1\u003c/sub\u003e on oxygenation and inflammatory factors, as well as the CPIS, the results of this study suggest that a clinical regimen of 0.4 FiO\u003csub\u003e2\u003c/sub\u003e + 0.1μg /kg PGE\u003csub\u003e1\u003c/sub\u003e is appropriate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial registration:\u003c/strong\u003e registry: www.chictr.org.cn\u003c/p\u003e\n\u003cp\u003eregistration number: ChiCTR1800018288\u003c/p\u003e","manuscriptTitle":"The Impact of Different Inspired Oxygen Concentrations Combined with Nebulized Prostaglandin E1 on Oxygenation in Patients Undergoing One- Lung Ventilation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-06 07:12:47","doi":"10.21203/rs.3.rs-5849993/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":"1dd08496-be29-4d23-ae8f-4b7c77649d05","owner":[],"postedDate":"February 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-07T15:53:13+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-06 07:12:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5849993","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5849993","identity":"rs-5849993","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}