Continuous epidural infusion versus programmed intermittent epidural bolus for labor analgesia: optimal configuration of parameters to reduce physician-administered top-ups.

BACKGROUND AND OBJECTIVES: Programmed intermittent epidural bolus (PIEB) is a delivery mode associated with decreased local analgesia dosing, motor block, and physician-administered top-ups (PATUs) during labor analgesia. We hypothesized that PIEB delivery at different settings will result in fewer PATUs for labor analgesia than the same hourly volume of a continuous epidural infusion (CEI).

METHODS: "Before and after" study design of combined spinal-epidural (CSE) for labor, with bupivacaine 0.0625%-fentanyl 2 mcg/ml and patient-controlled epidural analgesia (PCEA; 5 ml bolus with 10 min lock-out). The "before" group (N = 120) received a CEI at 10 ml/hour. PIEB groups received a programmed bolus of 10 ml: every 60 min (PIEB60, N = 120), every 45 min (PIEB45, N = 140), or every 45 min with high flow (500 ml/hour) (PIEB45HF, N = 25).

MAIN OUTCOME MEASURES: Number of women requesting a PATU, time intervals from CSE to PATU and to delivery, and obstetric outcomes.

RESULTS: There was no difference in the proportion of women requesting PATUs between the CEI and PIEB60 groups (45/120 versus 52/120, respectively; p > .05). The PATU rate was lower in the PIEB45 group compared with the PIEB60 and CEI groups (23/140 versus 52/120 and 45/120, p < .005 and p < .05, respectively), and in the PIEB45HF versus PIEB60 groups (5/25 versus 52/120, p < .05). No difference in other outcomes was observed.

CONCLUSIONS: The number of women requesting a PATU was lowest with the PIEB45 and PIEB45HF settings. There were no differences in any other outcomes between groups. This study emphasizes the many variations in programming that need to be further tested to establish the benefits of PIEB delivery compared with traditional CEI with PCEA.