Continuous epidural infusion vs programmed intermittent epidural bolus for labour analgesia: a prospective, controlled, before-and-after cohort study of labour outcomes

Background: Recent evidence that programmed intermittent epidural bolus (PIEB) improves maternal outcomes encouraged us to change our labour epidural analgesia protocols and investigate if we could achieve similar results in a clinical setting. Methods: We conducted a prospective, controlled, before-and-after cohort study. Outcomes after labour analgesia delivered by continuous epidural infusion (CEI) with ropivacaine 0.2% and fentanyl 2 mu g ml(-1) were compared with PIEB with patient controlled epidural analgesia (PIEB+PCEA) with ropivacaine 0.1% and fentanyl 2 mu g ml(-1). The primary outcome was lower limb motor block. Secondary outcomes were local anaesthetic and fentanyl dose, duration of the second stage of labour, mode of delivery, and maternal satisfaction. Outcomes were compared using univariate t-test, chi(2) test or Fisher's exact test. Significant differences in outcomes were further evaluated by multiple regression analysis. Results: A total of 397 women completed the study (CEI 188; PIEB+PCEA 209). The PIEB+PCEA group had significantly fewer patients with motor block [CEI 41/188 (21.8%) vs PCEA+PIEB 2/209 (1.0%), P<0.001], shorter second stage of labour for primiparous women [CEI 108.2 (61.2), mean (standard deviation), min vs PIEB+PCA 79.4 (55.1) min, P<0.001], and received less ropivacaine [CEI 72.5 (43.0) mg vs PIEB+PCEA 40.4 (23.8) mg, P<0.001]. There was no significant difference in mode of delivery, fentanyl dose, or maternal satisfaction. Conclusions: Benefits of PIEB+PCEA over CEI previously demonstrated in small randomised controlled trials were reproducible on a larger scale in a clinical setting.