Maximizing patient safety and comfort while minimizing adverse sequelae are continuing
anesthetic challenges. The purpose of this study was to examine three
anesthetic techniques utilizing
alfentanil with regard to time to awakening, time to orientation and incidence of
nausea and
vomiting.
Surgical procedures were limited to knee arthroscopy, laparoscopy and dental extractions. Unpremedicated ASA I/II outpatients (n = 74) between the ages of 18 and 59 were randomly assigned to one of three groups: Group I:
alfentanil + 67% N2O + 33% O2 Group II:
alfentanil + 67% N2O + 33% O2 +
droperidol 0.015 mg/kg Group III:
alfentanil + 100% O2 + 0.7%
isoflurane Anesthesia was induced with
alfentanil 40 micrograms/kg,
atracurium 0.4 mg/kg,
thiamylal 4 mg/kg and 100% O2 and was maintained according to group assignment. The
anesthetic was supplemented as clinically indicated with incremental boluses of
alfentanil 10 micrograms/kg. Upon completion of surgery, muscle relaxation was reversed with
edrophonium 0.75 mg/kg and
atropine 0.015 mg/kg. Analyses indicated that the three groups were comparable in terms of potentially confounding variables including gender, race,
surgical procedure, age, percent of ideal body weight, case length and dose of
alfentanil in micrograms/kg/hr. Time to awakening was significantly shorter in the two N2O groups by approximately 1.5 minutes, as compared to the O2 and
isoflurane group (p = .0060). Time to orientation was significantly shorter in the N2O groups by approximately 1.5 minutes also, as compared to the O2 and
isoflurane group (p = .0142). The two N2O groups did not differ significantly in either measure. The incidence of
vomiting in the postanesthesia recovery room (PARR) indicated a significant difference (p = .0317) among groups with
vomiting occurring 45.8% of the time in Group I, 28.8% of the time in Group II and 8% of the time in Group III. Total
emetic score (
nausea and
vomiting) in the PARR indicated a significant difference (p = .03) among groups with symptoms occurring 50% of the time in Group I, 28% of the time in Group II, and 16% of the time in Group III.