Analgesic efficacy of inter-semispinal fascial plane block in Patients undergoing Cervical Spine Surgery through Posterior Approach: a randomized controlled trial.

ABSTRACT

BACKGROUND: Posterior cervical spine surgery is commonly performed in elderly patients with significant comorbidities and is considered one of the most painful surgical procedures. Accordingly, perioperative pain management during posterior cervical spine surgery represents a unique challenge for anesthesiologists. Inter-semispinal plane block (ISPB) represents a promising analgesic technique for spine surgery through the blockade of the dorsal rami of the cervical spinal nerves. The present study aimed to investigate the analgesic effect of bilateral ISPB as an opioid-sparing nerve block technique for posterior cervical spine surgeries. METHODS: This prospective randomized controlled trial enrolled 52 patients planned for cervical spine surgery via the posterior approach. Patients were randomly assigned to one of two groups in a one-to-one ratio, with 26 patients allocated to the block group (ISPB) who received general anesthesia preceded by bilateral ISP using 20 mL 0.25% bupivacaine on each side and the remaining 26 patients allocated to the control group who received general anesthesia only. The primary outcome was total perioperative opioid consumption through two co-primary outcomes, i.e. total amount of fentanyl administered intraoperatively and total morphine consumption during the first 24 hours postoperatively. The secondary outcomes included intraoperative hemodynamic parameters, assessment of numerical rating scores (NRS) during the first 24 hours postoperatively, time to first rescue analgesia and opioid-related side effects. RESULTS: A significantly lower amount of intraoperative fentanyl was administered in the ISPB group (median, 175 µg; range, 110-220 µg] compared to the control group [median, 290 µg; range 110-350 µg). Patients in the ISPB group consumed significantly lower doses of morphine (median, 7 mg; range, 5-12 mg]) within the first 24 h postoperatively compared to the control group (median, 12 mg; range, 8-21 mg). In addition, NRS values were significantly lower in the ISPB group during the first 12 h postoperatively than in the control group. No significant differences in mean arterial pressure (MAP) or heart rate (HR) were observed between intraoperative time points in the ISPB group. However, a significant increase in MAP was observed during surgery in the control group (p < 0.001). The incidence of opioid side effects such as nausea, vomiting, and sedation was significantly greater in the control group compared to the ISPB group. CONCLUSIONS: Inter-semispinal plane block (ISPB) represents an effective analgesic technique and reduces opioid consumption in both intra- and postoperative settings. Moreover, the ISPB could significantly decrease opioid-associated side effects.