Programmed intermittent boluses vs continuous epidural infusion in labor using an adrenaline containing solution: A randomized trial.

Background: Traditionally, epidural analgesia has been maintained using a continuous infusion (CEI) with the addition of patient-controlled boluses (PCEA). In recent years, programmed intermittent boluses (PIEB) has emerged as an alternative showing better efficacy in randomized studies. In this study, the aim was to test PIEB + PCEA vs CEI + PCEA using an epidural solution containing adrenaline.

Methods: In total, 150 nulliparous and multiparous laboring women were randomized to maintain epidural analgesia with either PIEB + PCEA (5 ml bolus every hour, 5 ml PCEA bolus lockout 20 minutes) or CEI + PCEA (5 ml/h, 5 ml PCEA bolus, lockout 20 minutes) using a solution of bupivacaine 1mg/ml, fentanyl 2 mcg/ml and adrenaline 2 mcg/ml. The primary outcome was total hourly consumption of the epidural solution. Secondary outcomes included hourly pain scores, motor block at 60 minutes and 10 cm cervical dilation, maternal satisfaction, and the need for anesthetist intervention and time to this intervention.

Results: We found no differences in hourly drug consumption between the groups (mean 9.0 ml/h (SD 3.7) (CEI group) vs. 8.1 ml/h (SD 2.0) (PIEB group), P = .08). We found a significant difference in number of successfully administered PCEA boluses (mean no. 3.9 (SD 4.1) (CEI group) vs. 1.9 (SD 2.0) (PIEB group), P < .001). We found no significant differences in pain score, motor block, maternal satisfaction and the need for anesthetist intervention.

Conclusion: In this study, we found no clinically relevant differences using PIEB + PCEA compared to CEI + PCEA when using an epidural solution containing adrenaline.

Editorial Comment: For labor epidural analgesia infusions, to optimize the analgesic effect, additional programmed intermittent boluses can be used as an alternative to patient-controlled boluses only. In this clinical trial, no differences in drug consumption or analgesic effect was observed when comparing these two different epidural bolus controls programs.