Epidural Gel-Foam Impregnated with Bupivacaine versus Paravertebral Intramuscular Bupivacaine for Postoperative Analgesia in Lumbar Spine Surgery: A Comparative Clinical Trial.

Objectives: This study aimed to compare the effect of epidural gel foam impregnated with bupivacaine and intramuscular paravertebral bupivacaine on analgesia after lumbar spine surgeries. Methods: In this single-blind clinical trial, 60 patients aged 18-65 years who underwent lumbar spine surgery under general anesthesia were randomly assigned to two groups. In the first group, a 1 × 5 cm strip of gel foam impregnated with 70 mg of 0.5% bupivacaine was placed in the epidural space. In contrast, in the second group, 70 mg of 0.5% bupivacaine was injected paravertebrally into the muscle. Pain scores based on the Visual Analogue Scale (VAS), analgesic prescriptions, time to first analgesic request, and total dosage during recovery and at 6, 12, and 24 hours postoperatively were recorded and compared between the groups. Results: No significant difference in average pain scores at different time points (recovery, 6, and 12 hours) was observed between the two groups (P > 0.05). However, at 24 hours postoperatively, a significant difference was found between the groups, with the VAS score in the bupivacaine-impregnated epidural gel foam group being significantly lower than that in the paravertebral intramuscular bupivacaine group (P = 0.04). Conclusion: Bupivacaine-impregnated epidural gel foam and paravertebral intramuscular bupivacaine provide similar analgesia during recovery and at 6 and 12 hours following spinal surgery. However, at 24 hours, the analgesia in the bupivacaine-impregnated epidural gel foam group is superior to that in the paravertebral intramuscular bupivacaine group.