Epidural volume extension (EVE) via a combined spinal-epidural (CSE) technique is the enhancement of a small-dose intrathecal block by epidural saline boluses. In this prospective, randomized, double-blind study, we compared the EVE technique with single-shot spinal anesthesia with respect to its sensory and motor block profile and hemodynamic stability. Sixty-two parturients (n = 31 in each group) undergoing elective cesarean deliveries were administered either spinal anesthesia with hyperbaric 0.5% bupivacaine 9 mg and fentanyl 10 microg or CSE comprising intrathecal hyperbaric 0.5% bupivacaine 5 mg with fentanyl 10 microg, followed by 0.9% saline 6.0 mL through the epidural catheter 5 min thereafter. In each group, the lowest systolic blood pressure (SBP), sensory block level to loss of pain from pinprick, and modified Bromage scores were recorded at 2.5-min intervals. The visual analog pain score (VAS), peak sensory block height, highest modified Bromage motor score, time for sensory regression to the tenth thoracic dermatome (T10), and motor block recovery were compared between groups. Both groups were comparable in demographic data, VAS scores, peak sensory block height, time for sensory regression to T10, and lowest SBP recorded. Patients in the EVE group demonstrated significantly faster motor recovery to modified Bromage 0 (73 +/- 33 min versus 136 +/- 32 min, P < 0.05).
Implications: When compared with conventional, single-shot spinal anesthesia, epidural volume extension of a small-dose spinal block provides satisfactory anesthesia for cesarean delivery with only 55% of the bupivacaine dose required and is associated with faster motor recovery of the lower limbs.