Comparison of midwife top-ups, continuous infusion and patient-controlled epidural analgesia for maintaining mobility after a low-dose combined spinal-epidural.

We studied 133 women given a combined spinal-epidural for analgesia in labour. The initial intrathecal dose contained bupivacaine 2.5 mg with fentanyl 25 micrograms. When the mothers were comfortable, they were allocated randomly to one of three groups: continuous infusion (group Cl, n = 46), midwife top-ups (group MW, n = 43) or patient-controlled epidural analgesia (group PCEA, n = 44), to maintain analgesia throughout labour. All epidural solutions contained 0.1% bupivacaine and fentanyl 2 micrograms ml-1. Motor block was assessed by the mother's ability to straight leg raise (SLR). Four hours after combined spinal-epidural analgesia, 88.1% of women could SLR in group MW, 83.7% in group PCEA and 57.8% in group Cl (P = 0.002). Total use of bupivacaine was highest in group Cl (mean 11.3 (SD 3.3) mg h-1) compared with group MW (7.5 (3.1) mg h-1) and group PCEA (9.1 (2.1) mg h-1) (P < 0.001). Analgesia was similar between groups and overall satisfaction was equally high.