Impact study of the introduction of low-dose epidural (bupivacaine 0.1%/fentanyl 2 μg.mL-1) compared with bupivacaine 0.25% for labour analgesia

We conducted a retrospective analysis of the obstetric effects of introducing a low-dose epidural regimen for epidural analgesia in labour. Before this, all women in our unit requesting epidural analgesia for labour received intermittent boluses (10 mL) of 0.25% bupivacaine. After the introduction of the low-dose service in March 2000, intermittent boluses (10 mL) of 0.1% bupivacaine with fentanyl 2 mug(.)mL(-1) 1 were given. The records of 300 women were examined, 150 who had received the standard regimen before the introduction of the new service and 150 women afterwards. The groups were compared for outcome of labour, quality of analgesia and any adverse events related to the epidural analgesia. There was a significant reduction in the low-dose group in the number of women requiring instrumental delivery (41% vs. 29%, P = 0.04). The need for indwelling bladder catheters was also reduced in the patients receiving the low-dose regimen (21.3% vs. 4.7%, P < 0.001). Duration of analgesia was longer in patients receiving bupivacaine 0.25% (mean minimum time between boluses 42.25 +/- 33.8 vs. 24.37 +/- 19.8 min, P < 0.001). The need for further anaesthetic intervention was higher with the low-dose regimen (24% vs. 34%, P = 0.037). Maternal satisfaction was high in both groups (95 and 97%, respectively). We conclude that the introduction of a low-dose regimen of epidural analgesia for labour reduces the incidence of instrumental deliveries. It also decreases the incidence of bladder catheterisation during labour, but the need for anaesthetic intervention may be greater. (C) 2002 Elsevier Science Ltd. All rights reserved.