BACKGROUND: Programmed Intermittent Epidural Bolus (PIEB) and Continuous Epidural Infusion (CEI) are widely used strategies for maintaining postoperative analgesia, typically combined with Patient-Controlled Epidural Analgesia (PCEA). Although PIEB is theorized to enhance epidural drug distribution and analgesic effectiveness through intermittent high-pressure boluses, evidence supporting its superiority over CEI in the postoperative setting remains inconsistent. METHODS: We conducted a systematic review and meta-analysis of Randomized Controlled Trials (RCTs) comparing PIEB and CEI, both with PCEA, in adult postoperative patients (PROSPERO CRD420251046001). PubMed, Embase, and Cochrane were searched until May 1, 2025. PRIMARY OUTCOME: pain at 24-hours. SECONDARY OUTCOMES: pain at other intervals, anesthetic consumption, and adverse events. Data were synthesized using a random-effects model; Risk of Bias (RoB-2) and small-study effects were assessed. RESULTS: Ten RCTs comprising 692 patients were included. No significant difference was found in 24-hour pain scores at rest (MD = -0.45; 95% CI -0.99 to 0.10) or movement (MD = -0.88; 95% CI -2.07 to 0.32). PIEB showed mildly lower pain at other time points and reduced total epidural volume (MD = -7.31 mL; 95% CI -13.7 to -0.92 mL). However, PIEB was associated with higher hypotension risk (RR = 1.71; 95% CI 1.05 to 2.78). No differences were found in opioid consumption, PCEA demands, or other adverse events. CONCLUSION: PIEB offers no significant analgesic advantage and increases hypotension risk compared to CEI in postoperative settings, when both are combined with PCEA. These findings should be interpreted with caution due to the limited number of studies and substantial heterogeneity. PROSPERO REGISTRY: :https://www.crd.york.ac.uk/PROSPERO/view/CRD420251046001.
Gonzalez et al. (2026) studied this question.