A multicenter evaluation of remifentanil for early postoperative analgesia

We evaluated the use of an infusion of remifentanil to provide postoperative analgesia during recovery from total intravenous anesthesia (TIVA) with remifentanil and propofol. One hundred fifty-seven patients from seven medical centers underwent abdominal, spine, joint replacement, or thoracic surgery. Remifentanil was titrated in an effort to limit pain to 0 or 1 on a 0-3 scale. At the end of the 30-min titration period, 78% of infusion rates were in the range of 0.05 to ≤0.15 μg · kg^-1 · min^-1, 5% were <0.05 μg · kg^-1 · min^-1, and 17% were >0.15 μg · kg^-1 · min^-1. Pain scores were 0 or 1 in 64% of patients. Nausea occurred in 35% and emesis in 8% of patients; the peak incidence of nausea followed discontinuation of the remifentanil infusion at the time of administering morphine. Respiratory adverse events (oxygen saturation by pulse oximetry [SpO₂] <90% or respiratory rate <12) affected 29% of patients. Apnea occurred in 11 patients (7.0%). There was a large variation in the incidence of respiratory depression between the centers, ranging from 0 to 75%. The explanation for the large variability in respiratory outcome was not evident.