Risk Factors Analysis for Clinical Important Postoperative Nausea and Vomiting

Drawing from prior studies, we conducted a sample size calculation for a predictive model using the website https://mvansmeden.shinyapps.io/BeyondEPV/. By setting the number of candidate predictors to 9, the events fraction to 0.14, and the criterion value for rMPSE to 0.04, we determined that a minimum total sample size of 900 is required, with a minimally expected event per variable of 13.9. All patients were classified into either the CI-PONV group or the non-CI-PONV group. All 56 perioperative clinical features, encompassing baseline characteristics, preoperative conditions, and intraoperative information, were considered as potential predictive factors. In the quest to uncover potential predictive factors associated with CI-PONV, we employed the least absolute shrinkage and selection operator (LASSO) to sift through clinically significant variables. Subsequently, we utilized stepwise regression based on the Akaike Information Criterion (AIC) to further refine the selection of the ultimate predictors. Finally, a logistic regression model was developed based on the selected factors influencing CIPONV. The discrimination of the model was assessed by the ROCAUC and the goodness of fit of the model was evaluated using the Hosmer-Lemeshow test and calibration plots. A nomogram based on the logistic regression model output was developed as a tool for clinical application.

Inclusion criteria

a) age between 18 and 75 years, b) having 3 or 4 Apfel risk factors, and c) scheduled to undergo laparoscopic gastrointestinal surgical procedures under general anesthesia.

Exclusion criteria

a) American Society of Anesthesiologists (ASA) physical status greater than 3, b) severe hepatic dysfunction, c) contraindications to fosaprepitant, 5-HT3 receptor antagonist, or dexamethasone, d) preoperative use of medications known to have antiemetic properties, e) presence of mental disorders or inability to communicate, and f) pregnant or nursing women.