Evaluation of impact of epidural volume extension on the quality of spinal anaesthesia in patients undergoing proximal femoral nailing surgeries – randomized controlled study

Introduction:
Epidural volume extension is technique aiming to mitigate spinal anaesthesia induced hypotension, by reducing the dose of local anaesthetics. The present study was executed to determine the effect of epidural volume extension subarachnoid block with 0.5% hyperbaric bupivacaine in patients undergoing proximal femoral nailing (PFN) regarding characteristics of sensory-motor block and postoperative analgesia.

Material and methods
In this prospective, double-blind trial conducted from October 2021 to April 2022, 105 adult patients scheduled to undergo PFN were randomised into groups: control (C), 10 mL NS (E1), and 20 mL NS (E2), to receive 10 mg hyperbaric bupivacaine intrathecally plus additional epidural volume extension with 10 and 20 mL normal saline in groups E1 and E2, respectively. The primary outcome measured was the duration of postoperative analgesia. The secondary outcomes measured included onset of sensory- motor block and duration of sensory block. P < 0.05 was considered statistically significant.

Results:
A significantly longer duration of postoperative analgesia was noted in patients receiving 10 and 20 mL epidural volume extension (365.09 ± 101.83 and 330.06 ± 35.22 vs. 265.77 ± 38.01 min in the control group, P < 0.01). Patients who received any epidural volume extension with either 10 or 20 mL had significantly quicker onset of sensory and motor block as well as prolonged duration of sensory block. No significant difference in duration of postoperative analgesia, and onset and duration of block was observed between patients receiving either 10 or 20 mL epidural volume extension.

Conclusions:
Epidural volume extension significantly shortened the onset of sensory-motor block and increased the duration of sensory block and postoperative analgesia in patients undergoing PFN under subarachnoid block; however, no such difference was observed between 10 and 20 mL epidural volume extension.