Efficacy of esmolol versus alfentanil as a supplement to propofol-nitrous oxide anesthesia

In 97 outpatients undergoing ambulatory arthroscopic procedures, we compared esmolol with alfentanil when used to supplement propofol-N2O-atracurium anesthesia according to a randomized, double-blind protocol. After an initial intravenous dose of 16 micrograms/kg alfentanil, or 2 mg/kg of esmolol, a variable-rate infusion of alfentanil or esmolol was administered to maintain a stable heart rate. After induction of anesthesia with 2.5 mg/kg of propofol, mean arterial pressure decreased to a larger extent in the alfentanil-treated patients. Although heart rate and mean arterial pressure increased in both groups after tracheal intubation, alfentanil more effectively blunted the hemodynamic response to this stimulus. Maintenance of anesthesia was adequate in both treatment groups. After discontinuation of anesthesia, patients in the esmolol group opened their eyes earlier (7.2 +/- 2.4 min vs 9.8 +/- 4.6 min) than those in the alfentanil group. Esmolol-treated patients also reported less sedation in the first 15 min of recovery than those receiving alfentanil. However, there were no differences in times to ambulation and discharge between the groups. Esmolol-treated patients reported more postoperative pain for the first 15 min of recovery and more esmolol-treated patients required postoperative opioid analgesia than those treated with alfentanil. There were no significant differences in the incidences of nausea and vomiting between the two groups. The authors conclude that esmolol may be used in place of alfentanil to supplement propofol-N2O-atracurium anesthesia in outpatients undergoing arthroscopic procedures. However, hemodynamic responses to tracheal intubation were larger with esmolol, and avoidance of alfentanil did not decrease the incidence of postoperative nausea and vomiting in this outpatient population.