Determination of the effective therapeutic dose of intrathecal sufentanil for extracorporeal shock wave lithotripsy.

UNLABELLED Intrathecal (IT) sufentanil provides effective analgesia for extracorporeal shock wave lithotripsy. However, the optimal dose of sufentanil has not been established. We designed a prospective, randomized, double-blinded study to determine the optimal dose of IT sufentanil. Sixty men were randomized to receive 12.5,15,17.5, or 20 microg of IT sufentanil (n = 15 for each group) via a combined spinal epidural technique. Inadequate analgesia was treated with IV propofol, and the epidural was activated for a pain score greater than 6 on a 10-point verbal analog pain scale. Intraoperative and postoperative visual analog pain scale scores were significantly higher in the 12.5-microg group compared with 20-microg group (3.2 +/- 1.6 vs 1.6 +/- 1.2, P < 0.05, and 1.1 +/- 0.5 vs. 0.5 +/- 0.4, P < 0.05, respectively). The smaller-dosage groups of IT sufentanil required significantly more supplemental boluses of propofol compared with the 20-microg group (67%, 53%, and 40% vs 6%, respectively, P < 0.05). However, pruritus was significantly diminished in the smaller-dosage groups compared with the 20-microg group (55%, 60%, and 67% vs 100%, P < 0.05). The time to discharge was significantly shorter in the 15-microg group compared with the 20-microg group (84 +/- 40 min vs 126 +/- 48 min, P < 0.05). These results suggest that 15 microg of IT sufentanil may be the optimal IT dose for patients undergoing extracorporeal shock wave lithotripsy. IMPLICATIONS Many anesthetic techniques are used for extracorporeal shock wave lithotripsy (ESWL). We have previously shown that intrathecal sufentanil was effective for ESWL, but was associated with a high incidence of itching. We tested 60 patients in four spinal sufentanil dose groups and found that doses of 15 and 17.5 microg provided the most effective analgesia with the fewest side effects for ESWL, with only mild itching.