Development and validation of a risk score to predict the probability of postoperative vomiting in pediatric patients: the VPOP score

BACKGROUND: Few data are available in the literature on risk factors for postoperative vomiting (POV) in children. OBJECTIVE: The aim of the study was to establish independent risk factors for POV and to construct a pediatric specific risk score to predict POV in children. METHODS: Characteristics of 2392 children operated under general anesthesia were recorded. The dataset was randomly split into an evaluation set (n = 1761), analyzed with a multivariate analysis including logistic regression and backward stepwise procedure, and a validation set (n = 450), used to confirm the accuracy of prediction using the area under the receiver operating characteristic curve (ROCAUC ), to optimize sensitivity and specificity. RESULTS: The overall incidence of POV was 24.1%. Five independent risk factors were identified: stratified age (>3 and 13 years: adjusted OR 2.46 95% CI 1.75-3.45; ≥6 and ≤13 years: aOR 3.09 95% CI 2.23-4.29), duration of anesthesia (aOR 1.44 95% IC 1.06-1.96), surgery at risk (aOR 2.13 95% IC 1.49-3.06), predisposition to POV (aOR 1.81 95% CI 1.43-2.31), and multiple opioids doses (aOR 2.76 95% CI 2.06-3.70, P < 0.001). A simplified score was created, ranging from 0 to 6 points. Respective incidences of POV were 5%, 6%, 13%, 21%, 36%, 48%, and 52% when the risk score ranged from 0 to 6. The model yielded a ROCAUC of 0.73 95% CI 0.67-0.78 when applied to the validation dataset. CONCLUSIONS: Independent risk factors for POV were identified and used to create a new score to predict which children are at high risk of POV.