Evaluation of thoracolumbar interfascial plane block for postoperative analgesia after herniated lumbar disc surgery: A randomized clinical trial

Background: Thoracolumbar interfascial plane (TLIP) block involves injection of local anesthetics between multifidus and longissimus muscles at the 3rd lumbar vertebral level assuming that it can block the dorsal rami of thoracolumbar nerves. Objective: The objective of this study was to evaluate the analgesic effects gained after performing TLIP block (analogous to the transversus abdominis plane [TAP] block, but intended for the back) in patients undergoing lumbar discectomy. Methodology: This was a prospective, randomized, double-blinded, controlled clinical trial. Computer-generated randomization numbers were used to allocate patients into two groups. A total of 102 patients scheduled for lumbar discectomy were considered eligible, of these 70 patients were randomly included in the analysis: 35 patients (control group) received the standard general anesthetic technique and 35 patients (TLIP group) received TLIP block with 20 ml mixture of 0.25% bupivacaine and 1% lidocaine on each side. The primary outcome was to compare the two groups with regard to pain scores, whereas the secondary outcomes included the time to first analgesic (TFA), 24-h morphine consumption, and side effects associated with morphine such as nausea, vomiting, and sedation. Results: TLIP group compared with the control group showed a significant reduction in the postoperative Visual Analog Scale for pain score both on rest and movement, with no statistically significant difference at 24 h during movement. TFA was significantly shorter in the control group compared to the TLIP group (82.00 ± 69.01 vs. 442.7 ± 126.47 min, P < 0.001). TLIP group had lower cumulative morphine consumption than control group of statistically significant difference (9.7 ± 6.38 vs. 25.88 ± 5.17 mg, P < 0.001). TLIP block group compared with the control group showed a significant reduction of nausea and a lower incidence of sedation. Conclusion: TLIP block is an effective and safe method for postoperative analgesia after lumbar discectomy.