[Sedation in spinal anesthesia. Comparison of remifentanil and propofol]

To assess the efficacy and safety of remifentanil for analgesia and sedation during subarachnoidea anesthesia, and to compare remifentanil with propofol.

Ninety ASA I-III patients undergoing orthopedic or traumatologic surgery under subarachnoid anesthesia were enrolled for prospective study and randomly assigned to two treatment groups. The propofol group (n = 45) received a single dose of 0.5 mg/kg followed by infusion at 3 mg/kg/h. The remifentanil group (n = 45) received a single dose of 0.5 microgram/kg followed by infusion at 0.1 microgram/kg/min. We evaluated quality of sedation, pain intensity during nerve blockade, hemodynamic and respiratory parameters and time until recovery.

The remifentanil group experienced less moderate-to-intense pain (13%) than did the propofol group (63%) (p < 0.01). Sedation was adequate in both groups and was easy to control by adjusting the rate of infusion. Times until recovery of consciousness and respiratory frequency after withdrawal of infusion until recovery of baseline levels were 7.87 +/- 3.54 min and 5.22 +/- 2.49 min, respectively, in the remifentanil group and 8.72 +/- 4.59 min and 5.36 +/- 2.49 min, respectively, in the propofol group, respectively. Patients in the remifentanil group experienced a significantly greater decrease in SpO2 than did those in the propofol group (20% and 4%, respectively; p < 0.05). Mean blood pressure was higher for patients treated with remifentanil. The incidence of vomiting was also higher in the remifentanil group than in the propofol group (9% vs 0%).

Remifentanil is more effective in reducing pain related to nerve blockade and level of sedation is lower; however remifentanil is associated with a higher incidence of respiratory depression and vomiting.