Does small-dose fentanyl improve perioperative outcomes in the ambulatory setting? A randomized, double-blind, placebo-controlled study.

BACKGROUND: Despite its widespread use, the beneficial effect of low-dose fentanyl administered at induction of anesthesia on perioperative outcomes has not been studied in the ambulatory setting. Therefore, this study was designed to test the hypothesis that administration of small-dose fentanyl vs. saline during induction reduces coughing and movements without adversely affecting recovery after day-surgery. METHODS: One hundred consenting outpatients scheduled to undergo superficial surgical procedures under general anesthesia with a laryngeal mask airway (LMA) device for airway management were randomly assigned to one of two treatment groups: control (n = 50) or fentanyl (n = 50). After administration of 2 ml of the unlabelled study medication containing either fentanyl (100 µg) or saline, anesthesia was induced with lidocaine 30-50 mg and propofol 2 mg/kg IV followed by the insertion of an LMA device. General anesthesia was maintained using a propofol infusion, 75 µg/kg/min, and desflurane (2-5% end-tidal) in 100% oxygen. RESULTS: Coughing was observed in six (12%) and ten (20%) in the fentanyl and control group, respectively (P = 0.41). The incidence of movements during surgery was lower in the fentanyl group (18% vs. 31%, P < 0001). There were no significant differences in early and late recovery times or pain scores between the two groups. CONCLUSION: Administration of a small-dose of fentanyl at induction of anesthesia significantly reduced purposeful movements during day-surgery under propofol-desflurane anesthesia. No significant difference was found in coughing or recovery times.