Validation of the Apfel scoring system for identification of High-risk patients for PONV

Abstract

Background and Aims: Postoperative nausea and vomiting (PONV) still present an important problem in anesthesia. In order to identify surgical patients who may benefit from prophylactic antiemetic medication, it is of interest to evaluate the risk factors for PONV using a simple scoring system. The simplified Apfel score includes four factors: female gender, nonsmoking status, postoperative use of opioids, and previous history of PONV or motion sickness. Each of these risk factors is supposed to elevate the incidence of PONV by about 20%. The aim of this study was to validate Apfel's clinical risk assessment score for identification of patients with high risk for PONV in our hospital. Materials and Methods: In a prospective study, 150 patients posted for various elective surgeries under general anesthesia with endotracheal intubation were analyzed and grouped into five groups, based on the Apfel risk scoring system. Each risk was given a score of 1, the total score being 4. PONV was monitored for 24 h and classified as grades 0, 1, and 2. Grades 1 and 2 were considered as PONV. The results obtained were analyzed for total incidence of PONV in each group of Apfel's scores and they were compared with the predicted incidence of PONV as per the documented Apfel's risk assessment. Collected data were analyzed by the Chi-square test, and the scoring system was assessed for sensitivity and specificity. Results: Of the 150 patients assessed, a total of 42% had PONV. Patients grouped under Apfel Score I had PONV incidence of 25.5%, the group with Score II had an incidence of 37.8%, the group with Score III had 64.6%, and the group with Score IV had 83.3%. This incidence of PONV corresponded to the predicted approximate values of 20% for Apfel Score I, 40% for Apfel II, 60% for Apfel III, and 80% for Apfel IV. Conclusions: The Apfel scoring system is simple and useful for identifying patients with high risk for PONV.