Buprenorphine-soaked absorbable gelatin sponge: an alternative method for postlaminectomy pain relief

There have been several reports of instillation of buprenorphine in the intact epidural space in an attempt to control postoperative pain, but none in which an absorbable gelatin sponge soaked with buprenorphine is placed directly in the epidural space. In the present study, carried out on 30 patients (study group) undergoing noncervical laminectomies, 0.3 mg buprenorphine diluted to 5 mL with normal saline soaked into an absorbable gelatin sponge was placed in the epidural space under direct vision. In 30 other patients (control group) undergoing laminectomies, absorbable gelatin sponge soaked with 5 mL normal saline was placed in the epidural space. Pulse rate, mean arterial pressure, respiratory rate, pain score by visual analog scale, duration of analgesia, and adverse effects, if any, were noted preoperatively and postoperatively at 1, 2, 3, 4, 5, 6, 12, 18, and 24 hours. The presence of any neurologic symptoms was also assessed at these time intervals as well as on the seventh postoperative day. The authors observed that changes in pulse rate, mean arterial pressure, and respiratory rate were not statistically significant between the control and the study groups. The pain relief score, duration of pain relief (14.8 +/- 0.77 hours in the study group vs. 0.66 +/- 0.15 hours in the control group), and sedation were significantly better in the study group. No patient demonstrated any respiratory depression (respiratory rate <12/min), bradycardia, pruritus, or neurologic pressure symptoms, although the incidence of nausea was higher in the study group.