Fast-tracking after immersion lithotripsy: General anesthesia versus monitored anesthesia care

Both monitored anesthesia care (MAC) and general anesthesia (GA) offer adva ntages over epidural anesthesia for immersion lithotripsy. We compared prop ofol-based MAC and desflurane-based GA techniques for outpatient Lithotrips y. After receiving midazolam 2 mg IV, 100 subjects were randomly assigned t o one of two anesthetic treatment groups. In the MAC group, propofol 50-100 mu g . kg(-1) . min(-1) IV was titrated to maintain an observer's assessme nt of alertness/sedation score of 2-3 (5 = awake/alert to 1 = asleep). Remi fentanil 0.05 mu g . kg(-1) . min-1 IV supplemented with 0.125 mu g/kg IV b oluses, was administered for pain control. In the GA group, anesthesia was induced with propofol 1.5 mg/kg IV and remifentanil 0.125 mu g/kg IV and ma intained with desflurane (2%-4% inspired) and nitrous oxide (60%). Tachypne a (respiratory rate >20 breaths/min) was treated with remifentanil 0.125 mu g/kg IV boluses. In the GA group, droperidol. (0.625 mg IV) was administer ed as a prophylactic antiemetic. Recovery times and postoperative side effe cts were assessed up to 24 h after the procedure. Compared. with MAC,the us e of GA reduced the opioid requirement and decreased movements and episodes of desaturation. (<90%) during the procedure. Although the GA group took l onger to return to an observer's assessment of alertness/sedation score of 5, discharge times were similar in both groups. We conclude that GA can pro vide better conditions for outpatient immersion lithotripsy than MAC sedati on without delaying discharge.