Intermittent epidural bolus versus continuous epidural infusions for labor analgesia: A meta-analysis of randomized controlled trials

There are inconsistent results regarding the efficacy and safety of intermittent epidural bolus (IPB) versus continuous epidural infusions (CPI) for labor analgesia. This study used a meta-analytic approach to assess the safety and treatment efficacy of IPB versus CPI for labor analgesia based on randomized controlled trials (RCTs). Four electronic databases were used to identify eligible RCTs. Pooled effect estimates at 95% confidence intervals (CIs) were calculated using a random-effects model. Twenty-two RCTs with 2,573 parturients were selected for final analysis. The findings revealed no significant differences between IPB and CPI for the incidences of cesarean and instrumental delivery. IPB was shown to be associated with shorter total duration of labor [weighted mean difference (WMD): -21.46; 95% CI: -25.07 to -17.85; P < 0.001], duration of the first of stage of labor (WMD: -13.41; 95% CI: -21.01 to -5.81; P = 0.001), and duration of the second stage of labor (WMD: -4.98; 95% CI: -9.32 to -0.63; P = 0.025). Furthermore, IPB significantly reduced the incidences of required anesthetic interventions compared with CPI [relative risk (RR): 0.61; 95% CI: 0.39-0.95; P = 0.030], whereas there was no significant difference between IPB and CPI for the time required in the first anesthetic intervention (WMD: 7.73; 95% CI: -33.68-49.15; P = 0.714). The local anesthetic IPB (bupivacaine equivalents) was associated with lower milligrams per hour of local anesthetic (WMD: -0.89; 95% CI: -1.41 to -0.36; P = 0.001) and better maternal satisfaction (WMD: 8.76; 95% CI: 4.18-13.35; P < 0.001). There were no significant differences between IPB and CPI for the risk of adverse events. This study found that parturients with IPB have short total duration of labor and duration of the first and second stage of labor, reduced requirements for additional anesthetic interventions, and improved maternal satisfaction.