Comparing Continuous Epidural Infusion and Programmed Intermittent Epidural Boluses as the Background Infusion for Parturient Controlled Epidural Analgesia: Analysis of the “Real World” Database Using Propensity Score Matching

Abstract

Background Although the difference in treatment efficacy between programmed intermittent epidural bolus (PIEB) and continuous epidural infusions (CEI ) for labor analgesia has been addressed in several previous randomized control trials, observational research on “real world” data is considered as the most important supplement of RCTs about the effectiveness of interventions to guide best clinical practice. We performed a prospective cohort study to compare the efficacy of CEI+PCEA vs. PIEB+PCEA for providing epidural analgesia during labor.

Methods We identified 1807 patients who received epidural analgesia for planned normal vaginal. Propensity score matching with a ratio of 1:1 was implemented to reduce selection bias. The primary outcome of interest was the incidence of motor block assessed with maximum Bromage score, occurring at least once throughout labor. Secondary outcomes included total local anesthetic volume and doses, duration of labor analgesia, the proportion of prolonged second stage of labor, the number of physician-administered epidural boluses, the physician evaluates during labor analgesia, mode of delivery, the incidence of at least one of abnormal vital signs during labor epidural, and Apgar score at 1 or 5 minutes.

Results After propensity score matching, a total of 1328 patients were matched. The motor block occurred less frequently in PIEB group than in CEI group (RR 0.39, 95% CI: 0.29, 0.54, p.0001). PIEB group received more fentanyl dose per hour with the mean difference of 8.85g (95% CI: 7.79, 9.91, p.0001), less bupivacaine per hour with the mean difference of 9.57mg (95% CI: 4.40, 14.57, p.0001). We found lower evaluated times per hour in PIEB group (PIEB:0.75 times per hour, CEI: 0.68 times per hour, MD: -0.07 times per hour, 95%CI: -0.10, -0.04, p.0001).There is no statistical difference in C-section delivery rate (RR 0.98, 95% CI: 0.84,1.13), instrumental vaginal delivery( RR 0.88, 95% CI:0.69, 1.13), and duration of second stage of labor (RR 0.91, 95%CI: 0.70, 1.18) between PIEB group and CEI group. The low Apgar score at 1-minute incidence was higher in PIEB group, and the risk ratio was 1.15 (95% CI: 0.96, 1.38, p>0.002).

Conclusions Our study showed that PIEB combines with PCEA was superior to CEI combined with PCEA for labor analgesia, including decreasing the incidence of motor block, lessening the local bupivacaine consumption, and reducing the workload of anesthetists. Further investigations into the association between high cumulative dose of fentanyl and increased incidence of low Apgar score in PIEB are needed.