Combined spinal-epidural for labor analgesia with low-dose bupivacaine but without any opioid in the spinal component : can we improve upon the traditional ?

Aim : To compare the efficacy and safety of combined spinal-epidural (CSE, with the spinal component using low-dose heavy bupivacaine without opioid) with low-dose epidural analgesia in labor. Methods : Sixty consenting adult parturients requesting epidural were randomly allocated to two equal groups to receive either low-dose epidural or CSE analgesia. The Epidural Group received 10ml of a mixture of 0.1% bupivacaine and 2 pg/ml fentanyl, followed by a 6 ml first bolus after 10 min if needed (not considered as a top-up). All patients received 8 ml/h continuous background infusion, with patient-controlled top-up bolus of 6ml with a lock-out interval of 12 min. In the CSE Group, 0.5% (heavy) bupivacaine 2.5 mg was used to produce spinal block (without concomitant use of any opioid), followed by epidural continuous background infusion of 8ml of 0.1% of bupivacaine and 2 mu g/ml of fentanyl, with a similar top-up provision as in the Epidural Group. Primary outcome was total drug consumption during labor, corrected by the duration of labor (ml/h). Results : Mean total drug consumption during labor was significantly less in the CSE group (9.69 ml/h) than in Epidural group (13.52 ml/h ; P < 0.001). CSE also led to significantly faster onset of analgesia and sensory block. There was no significant difference between the two groups with regard to all other variables. Maternal satisfaction was rated as excellent' by all subjects. Conclusions : CSE using low-dose heavy bupivacaine without opioid required less drug consumption produced faster onset of pain control and sensory block than low-dose epidural analgesia. There were no other significant inter-group differences.