Labour outcomes with epidural analgesia: an observational before-and-after cohort study comparing continuous infusion versus programmed intermittent bolus plus patient-controlled analgesia.

BACKGROUND Scientific evidence shows that programmed intermittent epidural bolus (PIEB) for labour analgesia achieves good obstetric outcomes. After implementing our institutional standard for epidural analgesia, we compared PIEB + patient-controlled epidural analgesia (PCEA) versus continuous epidural infusion (CEI). METHODS In an observational cohort study, we compared CEI with 0.2% ropivacaine + 100-μg fentanyl initial bolus versus PIEB+PCEA with 0.1% ropivacaine + 2 μg ml-1 fentanyl in primiparous women. The primary outcome was mode of delivery. Secondary outcomes were duration of the second stage of labour and total ropivacaine and fentanyl doses. Other outcomes, in the PIEB+PCEA group only, were motor block, use of PCEA and rescue bolus, maternal mobility and maternal satisfaction. Univariate statistical analysis was performed using the χ²-test, analysis of variance or nonparametric Kruskal-Wallis test. Multivariate analysis was performed using multiple logistic regression analysis. RESULTS 221 patients completed the study (CEI 116; PIEB+PCEA 105). Multiple logistic regression showed that the PIEB+PCEA group had significantly fewer caesarean sections [CEI (14%) vs. PIEB+PCEA (5%), p=0.015] and instrumental deliveries, after correcting for confounders [OR = 0.49; 95% CI: 0.27-0.89]. The second stage of labour did not significantly differ between groups. Total ropivacaine dose was significantly lower with PIEB+PCEA. There was no relationship between mild motor block and increased use of PCEA in the PIEB+PCEA group. Mode of delivery and duration of the second stage of labour were not influenced by motor block either. Maternal satisfaction was high. CONCLUSIONS PIEB+PCEA offers obstetric and analgesic advantages over CEI in daily clinical practice.