Comparison of low-dose epidural with combined spinal-epidural analgesia for labour

We have performed a randomized comparison of two low-dose epidural regimens for analgesia in labour, differing only in the manner in which initial ana lgesia was established. In the epidural (EPI) group, 484 women received a l oading dose of 20 ml of 0.1% bupivacaine with fentanyl 2 mu g ml(-1). In th e combined spinal-epidural (CSE) group, 524 women received a spinal injecti on of plain bupivacaine 2.5 mg with fentanyl 25 mu g. In both groups, these initial doses were followed by 0.1% bupivacaine with fentanyl 2 mu g ml(-1 ) infused at a rate of 12 ml h(-1), with 20-ml top-ups for breakthrough pai n. The groups were compared for midwife assessment of analgesic efficacy, d elivery mode, patient assessments of first stage analgesia, second stage an algesia, overall analgesia, motor block and complications. Midwives, who we re nor, blinded to the treatment groups, assessed 61.6% of CSE as providing 'excellent' analgesia compared with 56.4% of epidurals (P=0.02). Patients assessed overall analgesia as 'excellent' in 74.8% of CSE compared with 71. 7% of epidurals (P=0.14). Other comparisons between groups revealed no diff erences. These findings may have been affected by an uneven distribution of multiparous women between the groups (25% in the EPI group and 34.2% in th e CSE group; P=0.002). However, subgroup analysis of primiparous and multip arous women did not alter the results.