Does functional ability in the postoperative period differ between remifentanil- and fentanyl-based anesthesia?

Study Objectives: To compare patients' functional ability in the 24-hour po stoperative period following a remifentanil compared to a hypnotic-fentanyl -treated anesthesia regimen using a 24-Hour Functional Ability Questionnair e. Design: Prospective, 1:1 single-blind, randomized, controlled effectiveness study. Setting: Multicenter study including 156 hospitals and ambulatory surgery f acilities. Patients: 2438 patients (1496 outpatients and 942 inpatients) 18 years of a ge or older, scheduled for elective surgeries under general endotracheal an esthesia, with an expected duration of unconsciousness of greater than or e qual to 30 minutes. Interventions: Patients were randomized to receive either intravenous remif entanil (0.5 mug/kg/min for induction and intubation; with the infusion rat e, decreased to 0.25 mug/kg/min after intubation) or fentanyl (administered according to anesthesiologists' usual Practice) as the opioid during surge ry. Concomitant hypnotic drugs were propofol and/or isoflurane (with or wit hout nitrous oxide) titrated according to protocol. Transition analgesia wi th either morphine or fentanyl was given in the remifentanil patients and a t the discretion of the anesthesiologists in the fentanyl patients. Measurements: A validated set Of measurements of functional ability, rather than more traditional clinical psychological methods, to compare the recov ery of patients from remifentanil- and fentanyl-treated anesthetic regimens up to 24 hours after surgery. Main Results: Remifentanil was statistically superior to fentanyl for the f our functional assessments evaluated: walking without dizziness, thinking c learly, concentration, and communicating effectively. These differences ref lect events occurring within the first 24 hours after anesthesia and surger y. Conclusions: A remifentanil-treated anesthetic demonstrated earlier return to some functions than a fentanyl-treated technique. Although functional as sessment is a field that is still in its infancy, a questionnaire to assess functional ability during the 24 hours after anesthesia may provide more P ractical information about anesthetic recovery than previously used, tradit ional psychomotor evaluations. (C) 2001 by Elsevier Science Inc.