Postoperative Nausea and Vomiting (PONV) : Usefulness of the Apfel-Score for identification of high risk patients for PONV

Objective : Postoperative nausea and vomiting (PONV) still represent an important problem in surgery. Treatment and prevention of PONV requires accurate risk stratification. The simplified Apfel-score includes the four factors female gender, no smoking, postoperative use of opioides and previous PONV or motion-sickness in patients' history. Each of these risk factors is supposed to elevate the PONV-incidence about 20%. The aim of the study was to validate this clinical risk assessment score in patients with high risk for PONV. Methods : In a prospective study 93 patients with high risk preoperative score for PONV (Apfel Score III and IV) were analyzed. Patients and nurses were interviewed using a standardized questionnaire at the time of discharge from the post-anesthesia care unit (PACU) as well as 6 hours and 24 hours after admission to the PACU. General anaesthesia was applied as total intravenous anaesthesia (TIVA) with mivacurium, propofol and remifentanil (no nitrous oxide / FI O2 0.5) Results : In the group with Apfel score III PONV occurred in 59.7% of patients and in the Apfel score group IV in 91.3% of all patients. The incidence of PONV corresponds to the predicted values of 60% for Apfel III and 80% for Apfel IV although the use of TIVA should have reduced the incidence of PONV about 26%. This apparent overestimation could be explained by the frequent questioning of patients and nurses for PONV leading to assessment of very minor symptoms. Conclusion : The Apfel-score is a useful and simple tool for stratification of patients with high risk for PONV.