Postoperative nausea and vomiting with special reference to risk factors and prevention in laparoscopic surgery

Abstract

The current incidence, risk factors and prevention of postoperative nausea and vomiting (PONV) were prospectively evaluated in 1703 inpatients. The objectives of the study were: 1) to create a predictive model based on patient characteristics in order to enable the estimation of the risk for PONV, 2) to ascertain the antiemetic efficacy of prophylactic intravenous ondansetron in comparison with droperidol and placebo against PONV following laparoscopic surgery, and 3) to evaluate the antiemetic effectiveness of combining ondansetron with a low dose of droperidol in high‐risk inpatients.The incidence of nausea and vomiting after common surgical procedures was high. In the recovery room, the overall incidence of nausea and vomiting was 18% and 5%, respectively, and over the whole 24‐h observation period the respective figures were 52% and 25%. The most significant predictive factors associated with an increased risk for the symptoms were female sex, a previous history of postoperative nausea and vomiting, a history of motion sickness, a longer duration of surgery and non‐smoking. Based on these five items, a risk score predicting nausea and vomiting was constructed with a moderately good discriminating power, as judged from the area under the receiver operating characteristic curve.Intravenous ondansetron 4 mg was ineffective in the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy. A higher dose of prophylactic ondansetron 8 mg effectively reduced the incidence and alleviated the intensity of PONV in women scheduled to have laparoscopy for gynaecological and general surgical procedures, as compared with placebo. The antiemetic efficacy of prophylactic ondansetron 8 mg and droperidol 1.25 mg was similar as for overall nausea during the 24‐h observation period, but ondansetron seemed to be slightly more efficacious in preventing vomiting. Both ondansetron and droperidol were well‐tolerated with only minor side‐effects.In a high‐risk, female, inpatient laparoscopic population, with a mean estimated risk of 65% for PONV, prophylactically administered ondansetron 8 mg in combination with either a 0.75 mg or 1.25 mg dose of droperidol reduced the incidence of post‐operative nausea to 35% and that of vomiting to 15% during the first 24 h after surgery. Of these drug combinations, the smaller dose of droperidol resulted in less postoperative sedation than the higher dose; both combinations being otherwise equally well‐tolerated without serious adverse events.These results indicate that postoperative nausea and vomiting can, to some extent, be predicted by a few patient characteristics, and in laparoscopic surgery ‐ which is associated with an increased risk for PONV ‐ the incidence can be reduced with either a single dose of ondansetron or droperidol or a combination of these drugs.