A RANDOMIZED, BLIND COMPARISON OF REMIFENTANIL AND ALFENTANIL DURING ANESTHESIA FOR OUTPATIENT SURGERY

We compared remifentanil, an esterase-metabolized opioid, with alfenta nil. as part of balanced anesthesia with at least 0.8% isoflurane duri ng outpatient surgery in a randomized, double-blind trial. One hundred two patients received remifentanil, and 99 patients received alfentan il. Patients who received remifentanil experienced significantly fewer stress responses to surgical stimuli (52.9% and 65.7%, P < 0.05); sig nificantly fewer remifentanil patients responded to skin closure (11% and 22%, P < 0.05) than patients who received alfentanil. Significantl y more patients in the alfentanil group required extra analgesia compa red with the remifentanil group (P < 0.05). Time to respond to verbal command was shorter for alfentanil than remifentanil (median 7 min vs 9 min), and times to spontaneous respiration (median 5 min vs 8 min), adequate respiratory rate (median 6 min vs 9 min), and tracheal extuba tion (median 6 min vs 9 min) were significantly shorter for alfentanil in comparison with remifentanil (P < 0.05). Remifentanil patients, ho wever, showed significantly better recovery of psychomotor and psychom etric function between 30 and 90 min after surgery (P < 0.05). The inc idences of hypotension intraoperatively and shivering postoperatively were significantly higher with remifentanil. No unexpected or serious adverse events were recorded with remifentanil; however, one patient w ho received alfentanil experienced severe recurrent respiratory depres sion after surgery. The metabolic profile of remifentanil allowed bett er intraoperative analgesia without compromising recovery. Implication s: The pharmacological profile of remifentanil, a new opioid for use i n anesthesia, suggests that rapid recovery will occur after its use. T his study of 200 outpatients shows that the differences suggested from kinetic studies are not always borne out in clinical practice, althou gh later recovery variables did, in fact, favor remifentanil.