A multicenter evaluation of total intravenous anesthesia with remifentanil and propofol for elective inpatient surgery

Remifentanil is a μ-opioid receptor agonist with a context sensitive half-time of 3 min and an elimination half-life ≤10 min. This study sought to evaluate the efficacy of remifentanil and propofol total in(ravenous anesthesia (TIVA) in 161 patients undergoing inpatient surgery. Remifentanil 1 μg/kg was given intravenously (IV) followed by one of two randomized infusion rates: small dose (0.5 μg · kg^-1 · min^-1) or large dose (1 μg · kg^-1 · min^-1). Propofol (0.5-1.0 mg/kg IV bolus and 75 μg · kg^-1 · min^-1 infusion) and vecuronium were also given. Remifentanil infusions were decreased by 50% after tracheal intubation. End points included responses (hypertension, 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 groups in intraoperative responses. Recovery from anesthesia was within 3-7 min in both groups. The most frequent adverse events were hypotension (systolic blood pressure [BP] < 80 mm Hg or mean BP < 60 mm Hg) during 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% large-dose group; P = NS) during maintenance. In conclusion, when combined with propofol 75 μg · kg^-1 · min^-1, remifentanil 1 μg/kg IV as a bolus followed by an infusion of 1.0 μg · kg^-1 · min^-1 effectively controls responses to tracheal intubation. After tracheal intubation, remifentanil 0.25-4.0 μg · kg^-1 · min^-1 effectively controlled intraoperative responses while allowing for rapid emergence from anesthesia.