THE POSTOPERATIVE INTERVIEW - ASSESSING RISK-FACTORS FOR NAUSEA AND VOMITING

Most studies of postoperative nausea and vomiting have concentrated on single etiologic factors and have not detailed the method of assessin g these symptoms. This study used postoperative interview data from pa tients at four teaching hospitals during 1988-89, to determine 1) risk factors for nausea/vomiting, 2) whether the type of surgery affected the rate of nausea/vomiting among female patients, 3) whether differen ces in rates across hospitals were due to differences in patient case- mix, and 4) whether there were differences in the rate of nausea/vomit ing among the patients of individual anesthesiologists. Research nurse s performed 16,000 interviews (59% of all inpatients) from a closed-qu estion standardized format. With a multiple logistic regression that c ontrolled simultaneously for all risk factors, factors associated with increased risk for nausea/vomiting for all patients included younger age, female, lower physical status score, no preoperative medical cond itions, nonsmokers, elective procedures, longer duration of anesthesia , inhaled anesthetics, use of intraoperative opioids, and gynecologic or ophthalmologic operations. Among women, risk factors were similar, with minor gynecologic surgery associated with increased risk (relativ e odds = 2.30). We found marked variations in the rate of nausea/vomit ing across hospitals (range, 39% to 73%), and these variations were no t explained by the case-mix of patients. The rate of nausea/vomiting v aried substantially across anesthesiologists in each hospital and the differences were not explained by differences in the patients they man aged. Thus in the time period immediately preceding the introduction o f newer antiemetic drugs, we found that the rates of this common probl em were persistently high as perceived from the patients' point of vie w.