A COMPARISON OF PROPOFOL AND REMIFENTANIL DURING MONITORED ANESTHESIACARE

Study Objective: To compare remifentanil, an esterase-metabolized opio id, to a standard propofol-based sedation technique for monitored anes thesia care (MAC). Design: Non-randomized, open label. Setting: Univer sity hospital. Patients: 44 healthy female outpatients undergoing brea st biopsy procedures under local anesthesia. Interventions: All patien ts received intravenous (IV) midazolam 2 mg, followed by a continuous infusion of either propofol 75 mu g/kg/min, or remifentanil 0.1 mu g/k g/min, which was subsequently titrated to maintain optimal patient com fort without respiratory depression. Surgical-related pain was treated by injecting additional local anesthetic solution and ''rescue'' bolu ses of fentanyl 25 mu g IV. Measurements and Main Results: Sedation, p ain, and discomfort were monitored using standardized rating scales at 1 to 5 minute intervals. Recovery times were measured from the end of the study drug infusions. Propofol resulted in significantly higher m edian sedation scores compared with remifentanil, with 73% of patients requiring a decrease in the propofol infusion rate because of ''exces sive'' sedation. Local anesthetic requirements, pain, and discomfort s cores during surgery were similar in both groups. Remifentanil resulte d in greater respiratory depression compared with propofol, with decre ases in the remifentanil infusion rate required by 41% of patients bec ause of a slow respiratory rate (< 8 bpm) and/or oxygen desaturation m easured by pulse oximetry (SpO(2), < 90%). Median times to ambulation and to being judged ''fit for discharge'' were significantly shorter f ollowing-propofol (40 and 47 minutes, respectively) compared with remi fentanil (52 and 58 minutes, respectively). Conclusion: Remifentanil p rovided comparable intraoperative conditions and patient comfort at a lower sedation level compared with propofol. However, remifentanil was associated with greater respiratory depression and a longer time to h ome readiness. (C) 1997 by Elsevier Science Inc.