Abstracts of Posters Presented at the International Anesthesia Research Society; 72nd Clinical and Scientific Congress; Orlando, FL; March 7-11, 1998: Ambulatory Anesthesia
Introduction: Nausea is the most frequent postoperative adverse event reported by patients undergoing surgery (20-80% incidence) . To compare the incidence of nausea following a remifentanil-based anesthetic regimen to previously reported rates, we examined the type and amount of maintenance hypnotic (propofol or isoflurane), presence of nitrous oxide, gender, type of procedure (abdominal laparoscopy or other), and type of postoperative analgesia (opioid or other).
Methods: Following local IRB approval, 250 centers consented and enrolled up to 10 subjects each who received remifentanil in an open-label, observational study. Subjects were males and females 18 years of age and older, ASA status 1-4, and scheduled for elective surgery under general anesthesia expected to last >or=to 30 minutes. Subjects were induced with 0.5-1.0 mcg/kg/min remifentanil concurrently with propofol or thiopental. After intubation, remifentanil was decreased to 0.25 mcg/kg/min and titrated as needed. Subjects received either isoflurane (0.2% end-tidal with N2 0 or 0.4% without N2 0) or propofol (50-100 mcg/kg/min with N2 0 or 75-150 mcg/kg/min without N2 0) for maintenance hypnosis. All subjects were contacted 24 hours postoperatively to assess whether any adverse events had occurred; all spontaneously reported episodes of nausea occuring from the end of surgery until 24 hours postoperatively were captured. The analyses were based on 1174 outpatients. An adjusted analysis was performed using logistic regression.
Results: (Table 1)
Discussion: The overall nausea rate after remifentanil was comparable to previously reported rates with general anesthesia. The incidence of nausea was higher in subjects receiving isoflurane with N2 0, particularly for females and subjects undergoing abdominal laparoscopic procedures. Statistical analyses, adjusted for all factors simultaneously, indicated that subjects who received postop opioid analgesia were 1.5 times more likely to experience nausea than subjects who received non-opioid analgesia postoperatively (p=.005).
1. Anesthesia for Ambulatory Surgery, 2nd ed., pg 463, 1991.