Association Between Operation Time And Postoperative Pulmonary Complications In Patients Undergoing Gastrointestinal Surgery Under General Anesthesia

Objective To evaluate the association between operation time and postoperative pulmonary complications(PPCs)in patients undergoing gastrointestinal surgery under general anesthesia.Methods The clinical data of patients undergoing elective gastrointestinal surgery under general anesthesia from January 2018 to March 2022 were retrospectively collected.The inclusion criteria were:(1)age>18 years old,(2)abdominal gastrointestinal surgery under general anesthesia with tracheal intubation.Exclusion criteria:(1)operation duration is less than 30 minutes,(2)emergency operation,(3)operation with liver,gallbladder,kidney and other organs.Incomplete clinical data and unreasonable cases were also eliminated.According to the anesthesia intubation time,patients were divided into the morning group(8:00-13:59)and afternoon group(14:00-20:00).The main outcomes was the occurrence of pulmonary complications(PPCs)during hospitalization after surgery,and the secondary outcomes was the NRS pain score within 3 days after surgery,Nausea and vomiting within 7 days after operation,occurrence of surgical site infection during hospitalization after operation,Postoperative length of hospital stay and unplanned readmission within three months.At the same time,clinical data such as the patient’s sex,age,BMI,ASA grade,smoking and alcohol history,preoperative complications,preoperative examination results,surgical method,surgical duration,surgical bleeding,intraoperative blood transfusion,intraoperative fluid infusion,anesthetic dosage,intraoperative use of vasoactive drugs were collected.In order to balance the differences in baseline characteristics of potential clinical data between the two groups,the original data of the morning group and afternoon group were matched with the propensity score(PSM)according to the nearest neighbor matching method of 1:1.The included covariates included: gender,age,BMI,ASA,ACCI score,ARISCAT score,smoking history,drinking history,hypertension history,preoperative hemoglobin,preoperative albumin,preoperative blood creatinine,operation mode,operation duration,intraoperative allogeneic blood transfusion and intraoperative blood loss.The matched data were analyzed by univariate analysis to find out the relevant factors of PPCs after operation,and the variables with statistical differences were included in the multivariate logistic regression analysis to evaluate the independent risk factors of PPCs in patients undergoing gastrointestinal surgery under general anesthesia.Results 1.A total of 3287 patients were included in the final study analysis.A total of 348(10.6%)had PPCs after gastrointestinal surgery,247 in the morning and101 in the afternoon.The average postoperative NRS pain rating was 2.76 points.There were 378 cases(11.50%)who had postoperative nausea and vomiting,213 cases(6.5%)of incision infection,146 cases(4.4%)of unplanned rehospitalization within 3 months,and the average postoperative hospital stay was 11.66 days.2.Before the propensity score match,there were statistically significant differences in gender,age,ARISCAT score,preoperative hypertension rate,preoperative hemoglobin and serum creatinine values,operation duration and intraoperative blood loss between the morning and afternoon groups(P<0.05).After propensity scores of the preoperative clinical factors were matched,a total of 1176 groups were successfully matched.After matching,There was no statistically significant difference in baseline indexes in the two groups such as sex,age,BMI,smoking and drinking history,ACCI score,ASA grade,ARISCAT score,preoperative hypertension rate,preoperative hemoglobin,preoperative white protein,serum creatinine value,operation mode,operation duration intraoperative blood loss and allogeneic blood transfusion ratio(P>0.05).3.After matching,the total incidence of PPCs in the morning group was higher than that in the afternoon group(11.1% vs 8.6%,P=0.038),and the postoperative pain score was slightly higher than that in the afternoon operation group(2.84 ± 1.10 vs 2.70± 1.12,P=0.002).There was no statistically significant difference between the two groups in the incidence of postoperative nausea and vomiting,incision infection,postoperative hospitalization days and unplanned readmission rate within 3 months(P>0.05).4.All patients with propensity score matching were analyzed by univariate and multivariate logistic regression.The results showed that BMI ≥ 28(OR: 2.020,95%CI: 1.327-3.075,P=0.001),ACCI score ≥ 5(OR: 1.915,95% CI: 1.217-3.014,P=0.005),increased ARISCAT score(OR: 1.036,95% CI: 1.05-1.058,P=0.001),hypertension history(OR: 1.474,95% CI: 1.085-2.002,P=0.013),Open surgery(OR:0.015,95% CI: 1.470-2.762,P=0.000),operation duration>150 minutes(OR: 1.590,95% CI: 1.15-2.247,P=0.009),intraoperative bleeding>200 ml(OR: 1.844,95% CI:1.109-3.064,P=0.018)and intraoperative glucocorticoid use(OR: 1.551,95% CI:1.094-2.199,P=0.014)were independent risk factors for PPCs.Conclusion Operation time was correlated with PPCs in patients undergoing gastrointestinal surgery.The incidence of PPCs in patients starting surgery in the morning is higher than that in the afternoon.But there was no significant effect of operation time on postoperative nausea and vomiting,incidence of incision infection,postoperative hospitalization days and unplanned readmission rate within 3 months.BMI ≥ 28,ACCI score ≥ 5,increased ARISCAT score,history of hypertension,open surgery,operation duration>150 minutes,intraoperative hemorrhage>200 ml and intraoperative use of glucocorticoid are independent risk factors for PPCs in patients undergoing gastrointestinal surgery under general anesthesia.