The Relationship Between Intraoperative Hypotension And Postoperative Nausea And Vomiting During Gynecological Laparoscopic Surgery:an Observational Study

Objective Postoperative nausea and vomiting(PONV)is a common complication of patients undergoing gynecological laparoscopic surgery.The incidence is high,which seriously affects the patient’s postoperative recovery.Studies have shown that perioperative gastrointestinal tissue ischemia and hypoxia may be related to postoperative nausea and vomiting.Blood pressure is a routine monitoring indicator during surgery,which can largely reflect the blood perfusion of gastrointestinal tissue.However,the relationship between intraoperative blood pressure and postoperative nausea and vomiting is still unclear.This study used a prospective cohort study design to explore the correlation between intraoperative blood pressure and postoperative nausea and vomiting,and provide a reference for hemodynamic management during clinical anesthesia.Methods This study is a prospective cohort observational study.A total of 487 cases of elective gynecological laparoscopic surgery,aged 18-65 years old,American Society of Anesthesiologists(ASA)grade I-III were collected patient.We excluded patients undergoing emergency surgery,laparotomy surgery,history of motion sickness before surgery,history of smoking,poor blood pressure control(systolic blood pressure greater than 180 mmhg),and other medical history of the respiratory system and cardiovascular system.We used mean arterial pressure(MAP)to analyze blood pressure data.According to the data we obtained,we set the absolute threshold of MAP(75mmhg,70mmhg,65mmhg,60mmhg)and relative threshold(20%,25%,30%,35%,40%of the baseline).We divided patients into PONV or Non-PONV group according to whether PONV appeared within 24 hours after operation.Analyze the differences in the characteristics of the two groups of patients.Analyze whether the MAP below a certain threshold is related to PONV in the three periods of intra-operation,before incision and after incision respectively.We start to analyze one by one from the highest to the lowest threshold.Based on the results of threshold analysis,we explored whether there is a difference in the AUCs of MAP between the PONV group and the Non-PONV group of patients who AUCs greater than 0.Univariate and multivariate logistic regression were used to analyze the correlation between mean arterial pressure and PONV.Results In our study,319(66.3%)patients developed PONV.There was no difference in Age,BMI,ASA grade,type of surgery,preoperative fasting time,opioid use,dexmedetomidine use,intraoperative:fluid,postoperative bedtime activity,postoperative food intake between PONV and NON-PONV group.After multivariate analysis,patients with MAP<65mmhg are more likely to develop PONV:intra-operation:65mmhg(OR 1.51;95%CI1.17-5.02;p=0.027),after skin incision:65mmhg(OR 2.01;95%CI1.53-9.27;p=0.035).For the AUCs analysis,the PONV group was higher than the NON-PONV group in the following period:AUCs of MAP<65mmhg during the intra-operation(OR 1.87;95%CI1.25-2.21;p=0.014);AUCs of MAP<65mmhg after skin incision(OR 2.23;95%CI1.62-3.21;p=0.009).Conclusion Based on our research results,MAP is less than 65mmhg during operation,especially after skin incision,increasing the incidence of PONV in gynecological laparoscopic surgery.Compare to the correlation between the decrease in blood pressure before skin incision and PONV,the occurrence of hypotension after skin incision may have a greater effect on PONV.