Randomised comparison of combined spinal-epidural and standard epidural analgesia in labour

Epidural analgesia has a well-established role in labour, but has the drawbacks of delayed onset and motor blockade. The combined spinal-epidural technique may overcome these drawbacks. We carried out a randomised observational study to assess maternal satisfaction with the standard and combined techniques among 197 women in labour. For combined spinal-epidural analgesia, bupivacaine (2.5 mg) and fentanyl (25 micrograms) were initially injected into the subarachnoid space, followed by top-ups of 15 mL 0.1% bupivacaine with 2 micrograms/mL fentanyl into the epidural space, as required. For standard epidural analgesia, 25 mg (10 mL of 0.25%) bupivacaine was injected into the epidural space, followed by top-ups of 6-10 mL 0.25% bupivacaine, as required. Post partum, each woman completed a questionnaire about her labour and scored various items on a visual analogue scale (0 = best, 100 = worst outcome). Overall satisfaction was greater in the combined spinal-epidural group than in the standard epidural group (median [IQR] score 3 [2-10] vs 9 [3-22]; p = 0.0002). Good analgesia was achieved in both groups, but the combined spinal-epidural had faster onset of analgesia and more of this group were satisfied with analgesia at 20 min (92/98 vs 68/99, p < 0.0001). 12 women in the combined spinal-epidural group had leg weakness (as shown by an inability to raise the straight legs) at 20 min, but this initial motor block had resolved in most of these mothers by 1 h. In the standard epidural group 32 had leg weakness at 20 min (p = 0.001), and the proportion of mothers with weakness increased in this group during labour. There were no differences in side-effects, except for mild pruritus, which was more common in the combined spinal-epidural group (42 vs 1%; p < 0.0001). Overall, women seem to prefer the low-dose combined spinal-epidural technique to standard epidurals, perhaps because of the faster onset, less motor block, and feelings of greater self-control.