Epidural Volume Extension In Combined Spinal Epidural Anaesthesia For Rapid Motor Recovery After Elective Caesarean SectionA Comparative Study

Background: Epidural volume extension with saline solution can contribute to enhancement of a small dose intrathecal local anaesthetic. The resultant substantial reduction in local anaesthetic dose produces a sufficient effective block, decreased side effect and less motor blockade. The aim of this study was to evaluate the sensory and motor block characteristics of 10ml epidural saline after intrathecal small dose local anaesthetic and opioid. Setting and Design: This prospective, randomized, double-blind study was conducted in a operation room setting of a university hospital. One hundred and five women (25-40 years) of ASA 1 and 11 physical status electively undergoing caesarean section under regional anaesthesia were investigated.Method and Material: After hospital Ethics Committee approval and written informed consent, 105 women were allocated randomly, into three groups (n=35), received 7mg of spinal hyperbaric 0.5% Bupivacaine (groupB7), 7mg of spinal hyperbaric 0.5% Bupivacaine followed by 10ml of Normal Saline through the epidural catheter, 5 minutes thereafter (group B7EVE) and 10mg of spinal hyperbaric 0.5% Bupivacaine without epidural volume extension (groupB10). All women also received 25mcg of Fentanyl intrathecally. The patients were assessed at 2.5 minutes interval for sensory block level to loss of pain from pin prick and for motor block using modified Bromage scale. We also recorded visual analogue scale, peak sensory block height, highest Modified Bromage scale, motor block recovery, incidences of side effects and ephedrine dose requirement.Result: Demographic data, duration of surgery, VAS, incidence of maternal side effects and ephedrine dose requirement were similar in all the groups. There was no difference in the peak sensory block heights between the groups during the study. The motor score was significantly lower in the group B7-EVE (grade-1 vs grade-3 in groupB7and groupB10, P=0.014). This was associated with a significantly faster motor recovery to Modified Bromage 0 in group B7-EVE (61-80mts vs 121-140mts in group B7 and 141-160mts in groupB10, P=0.0001).Conclusion: This study demonstrates a benefit in using epidural volume extension with 10ml normal saline, as a part of a combined spinal epidural technique by providing a more rapid motor recovery of the lower limbs after elective caesarean section.