During labour, the effects of adding a programmed intermittent epidural bolus (PIEB) baseline analgesic regimen to patient-controlled epidural analgesia (PCEA) remain uncertain.

This single centre prospective double-blinded controlled study randomised nulliparous women over 35 weeks of gestational age in a PCEA + PIEB or PCEA only group. After an epidural analgesia catheter was inserted, a specific pump administered a solution of levobupivacaine 0.625 mg mL⁻¹, sufentanil 0.25 µg mL⁻¹, and clonidine 0.375 µg mL⁻¹. In both groups the PCEA mode delivered an 8 mL bolus with a lockout period of 8 min. In the PCEA + PIEB group, women also received a programmed 8 mL bolus every 60 min. Additional bolus were allowed if required. The primary outcome was the hourly consumption of levobupivacaine from epidural catheter placement to new-born delivery. Secondary outcome were motor block, oxytocin use, sufentanil consumption, additional bolus required, instrumental vaginal delivery, unplanned caesarean section, pain during labour and women’s satisfaction.

Analysis included 162 and 155 women in the PCEA and PCEA + PIEB groups, respectively. The median [IQR] hourly consumption of levobupivacaine was significantly lower in the PCEA group (9.9 (7.8–12.4] mg h⁻¹) as compared to the PCEA + PIEB group (11.2 [7.9–14.3] mg h⁻¹; p = 0.046). The difference between medians was 1.3 mg h⁻¹ 95 % CI (0.1–2.9). There was no difference between groups for secondary outcomes.

PCEA only modestly decreased the hourly consumption of local anaesthetic as compared to PCEA + PIEB but the difference was not clinically relevant.