Anterior peri-iliopsoas muscle space block for analgesia in lower-limb orthopedic surgery: A randomized controlled trial.

BACKGROUND

A combined lumbar and sacral plexus block may offer unilateral analgesia for the entire lower limb. However, the lumbar plexus block presents challenges due to the plexus's deep location and proximity to vital structures. Moreover, this technique often requires repositioning the patient, which can be painful or risky, especially in cases of multiple or spinal fractures. This study evaluated a novel anterior peri-iliopsoas muscle space block using a single skin puncture for perioperative analgesia in lower limb orthopedic surgery. Perfusion index was assessed as a supportive physiological marker of sympathetic change after the block.

METHODS

This prospective randomized controlled trial included 56 patients undergoing unilateral orthopedic procedures involving the knee region. Patients were randomly assigned to either a control group receiving only general anesthesia (GA) or a block group receiving preoperative peri-iliopsoas muscle space block (PIMSB) followed by GA. The primary outcome was cumulative postoperative morphine consumption during the first 24 h. Secondary outcomes included intraoperative fentanyl consumption, preoperative pain scores before and 30 min after PIMSB, postoperative surgical-site NRS scores within 24 h, time to first analgesic request, perfusion index readings before and at 10, 20, and 30 min after the block, and block-related complications.

RESULTS

PIMSB was associated with lower postoperative morphine consumption than the nonblock group (5.6 ± 1.3 mg vs. 16.1 ± 3.0 mg; between-group difference, 10.5 mg; 95% CI, 9.28-11.78; p < 0.001) and lower intraoperative fentanyl consumption (166.4 ± 20.1 μg vs. 241.1 ± 24.1 μg; between-group difference, 74.7 μg, 95% CI: 62.82-86.58, p < 0.001). Preoperative numerical rating score (NRS) significantly decreased after the block, and there were notable differences between the PIMSB and nonblock groups regarding postoperative pain at the surgical sites. PI readings in the operative limb were significantly higher after the PIMSB and continued to increase during the monitoring period.

CONCLUSIONS

PIMSB using a single skin puncture was associated with lower opioid requirements and lower postoperative pain scores after unilateral orthopedic procedures involving the knee region.