A MULTICENTER EVALUATION OF TOTAL INTRAVENOUS ANESTHESIA WITH REMIFENTANIL AND PROPOFOL FOR ELECTIVE INPATIENT SURGERY

Remifentanil is a mu-opioid receptor agonist with a context sensitive half-time of 3 min and an elimination half-life less than or equal to 10 min. This study sought to evaluate the efficacy of remifentanil and propofol total intravenous anesthesia (TIVA) in 161 patients undergoi ng inpatient surgery. Remifentanil 1 mu g/kg was given intravenously ( IV) followed by one of two randomized infusion rates: small dose (0.5 mu g . kg(-1). min(-1)) or large dose (1 mu g . kg(-1). min(-1)). Prop ofol (0.5-1.0 mg/kg IV bolus and 75 mu g . kg(-1). min(-1) infusion) a nd vecuronium were also given. Remifentanil infusions were decreased b y 50% after tracheal intubation. End points included responses (hypert ension, tachycardia, and somatic responses) to tracheal intubation and surgery. More patients in the small-dose than in the large-dose group responded to tracheal intubation with hypertension and/or tachycardia (25% vs 6%; P = 0.003) but there were no other differences between gr oups in intraoperative responses. Recovery from anesthesia was within 3-7 min in both groups. The most frequent adverse events were hypotens ion (systolic blood pressure [BP] < 80 mm Hg or mean BP < 60 mm Hg) du ring anesthesia induction (10% small-dose versus 15% large-dose group; P = not significant [NS]) and hypotension (27% small-dose versus 30% large-dose group; P = NS), and bradycardia (7% small-dose versus 19% l arge-dose group; P = NS) during maintenance. In conclusion, when combi ned with propofol 75 mu g . kg(-1). min(-1), remifentanil 1 mu g/kg IV as a bolus followed by an infusion of 1.0 mu g . kg(-1). min(-1) effe ctively controls responses to tracheal intubation. After tracheal intu bation, remifentanil 0.25-4.0 mu g . kg(-1). min(-1) effectively contr olled intraoperative responses while allowing for rapid emergence from anesthesia.