Transdermal nitroglycerine enhances spinal sufentanil postoperative analgesia following orthopedic surgery

Background Sufentanil Is a potent but short-acting spinal analgesic used to manage perioperative pain. This study evaluated the influence of transderm al nitroglycerine on the analgesic action of spinal sufentanil, in patients undergoing orthopedic surgery. Methods: Fifty-six patients were randomized to one of four groups, Patients mere premedicated with 0.05-0.1 mg/kg intravenous midazolam and received 1 5 mg bupivacaine plus 2 mi of the test drug intrathecally (saline or 10 pg sufentanil), Twenty to 30 min after the spinal puncture, a transdermal patc h of either 5 mg nitroglycerin or placebo was applied. The control group re ceived spinal saline and transdermal placebo. The sufentanil group received spinal sufentanil and transdermal placebo. The nitroglycerin group receive d spinal saline and transdermal nitroglycerine patch. Finally, the sufentan il-nitroglycerin group received spinal sufentanil and transdermal nitroglyc erine, Pain and adverse effects were evaluated using a 10-cm visual analog scale. Results: The time to first rescue analgesic medication was longer for the s ufentanil-nitroglycerin group (785 +/- 483 min) compared with the other gro ups (P < 0.005), The time to first rescue analgesics was also longer for th e sufentanil group compared with the control group (P < 0.05), The sufentan il-nitroglycerin group group required less rescue analgesics in 24 h compar ed with the other groups (P < 0.02) and had lesser 24-h pain visual analog scale scores compared with the control group (P < 0.005), although these sc ores were similar to the sufentanil and nitroglycerin groups (P > 0.05). Th e incidence of perioperative adverse effects was similar among groups (P > 0.05), Conclusions: Transdermal nitroglycerine alone (5 mg/day), a nitric oxide ge nerator, did not result in postoperative analgesia itself, but it prolonged the analgesic effect of spinal sufentanil (10 mu g) and provided 13 h of e ffective postoperative analgesia after knee surgery.