Comparison of the Analgesic Effects of Ultrasound Guided Supra-Inguinal Fascia Iliaca Block with Femoral Nerve Block for Surgical Fixation of Hip Fractures

Abstract

Introduction: Regional anaesthesia techniques have been used for perioperative analgesia for hip fractures. The supra-inguinal approach to fascia iliaca block (FIB) can potentially provide superior analgesia compared to femoral nerve block (FNB) by blocking the obturator and lateral femoral cutaneous nerves. We aimed to evaluate the analgesic effect of single shot FIB and FNB for surgical fixation of hip fractures. Methods: After obtaining ethics approval and written, informed consent, 30 patients undergoing surgical fixation of hip fractures were recruited and randomized into 2 groups. Patients received either a single shot FIB or FNB with 0.5% Ropivacaine 30 mls, and a subarachnoid block. Pain scores were assessed pre-operatively, post-block, in recovery and at 24 hours post-operatively. Time to first analgesic, oxynorm consumption, opioid related side effects and block related complications were assessed at 24 hours. Results: There were no statistically significant difference in post-block pain scores, median (IQR) of 0 (0 - 0) versus 0 (0 - 0) at rest and 3 (2 - 6) versus 5 (2 - 6) on positioning for spinal; and 24 hour pain scores were 0 (0 - 0) versus 0 (0 - 0) at rest and 4 (2 - 5) versus 5 (2 - 6) on movement for FIB and FNB groups respectively. 5 patients from each group required post-operative opioids, post-operative opioids requirement were similar. Conclusions: Though ultrasound guided supra-inguinal FIB was more consistent in blocking the lateral femoral cutaneous nerve then a femoral nerve block, this did not translate to any difference in terms of pain scores, opioid consumption and side effects.