BACKGROUND: Postoperative nausea and vomiting (PONV) along with postoperative pain is one of the most frequently encountered complaints after the surgery. The goal of this study is to elucidate the probable high risks factors of PONV by making 24 hr-observations on 4008 patients undergone general anesthesia.

METHODS: PONV scores (0: no PONV; 1, nausea; 2, retching; 3, vomiting) and characteristics of patient, surgery, anesthesia were recorded by patient interview and chart review at post anesthesia care unit and at ward 24 hours after operation. Risk factors of PONV were investigated by Odds ratio and P value. Multiple regression analysis was performed to produce the provability of PONV.

RESULTS: Incidence of PONV was 26.1% at PACU and 22.9% at ward. Total incidence of PONV during 24 hrs was 39.3. High risk factors of PONV were as follows in decreasing order: 1) female, 2) history of PONV or motion sickness, 3) nonsmoker, 4) operative time of longer than 60 minutes and 5) patient controlled analgesia. P (probability of PONV) = 1/1 + e^-Z Z = -1.928 + 0.899 (Gender) + 0.664 (Hx) + 0.558 (OP-duration) + 0.261 (Smoking Status) + 0.184 (Postop-opioid).

CONCLUSIONS: We could identify 5 risk factors and developed a Korean PONV risk model enabling to predict the probability of PONV by this study of 4008 patients.