Author: Maria Sgouraki, et al.
Cureus 18(6): e110560.
Programmed intermittent epidural bolus, or PIEB, is increasingly used as an alternative to continuous epidural infusion for maintaining labor analgesia. This study compared the two techniques with particular attention to maternal satisfaction, breakthrough pain, rescue interventions, medication consumption, and adverse effects.
The investigators studied 192 term pregnant women receiving labor epidural analgesia. Ninety-six received PIEB, and 96 received continuous epidural infusion. The study was observational and nonrandomized, with treatment determined by routine departmental practice or the attending anesthesiologist.
The PIEB regimen consisted of 6 mL of 0.0625% bupivacaine with fentanyl 2 µg/mL every 60 minutes. The continuous-infusion group received the same solution at 8 mL per hour. Both groups had access to 5-mL patient-controlled epidural analgesia boluses with a 20-minute lockout period.
Key findings
• Average maternal satisfaction was higher with PIEB: 8.6 versus 7.9 on a 10-point scale.
• Seventy-five percent of women in the PIEB group reported high satisfaction compared with 58.3% in the continuous-infusion group.
• Breakthrough pain occurred in 22.9% of women receiving PIEB compared with 39.6% receiving continuous infusion.
• Physician-administered rescue boluses were required in 18.8% of PIEB patients compared with 33.3% of continuous-infusion patients.
• Women receiving PIEB activated patient-controlled epidural boluses less often.
• Eighty-seven and one-half percent of women in the PIEB group said they would choose the same technique again, compared with 76% in the continuous-infusion group.
Medication consumption
PIEB produced better analgesic outcomes while using less medication.
The average total local anesthetic volume was 68.2 mL with PIEB compared with 75.6 mL with continuous infusion.
Average fentanyl consumption was 136.4 µg with PIEB compared with 151.2 µg with continuous infusion.
These findings suggest that intermittent boluses may distribute epidural medication more efficiently than a slow continuous infusion.
Safety
Rates of hypotension, pruritus, nausea, vomiting, and motor block were low and did not differ significantly between the groups.
Motor block occurred in 9.4% of women receiving PIEB and 14.6% receiving continuous infusion, although this difference was not statistically significant.
Clinical implications
PIEB appears to provide more consistent epidural analgesia, fewer episodes of breakthrough pain, less need for anesthesiologist intervention, and lower local anesthetic and opioid consumption.
The potential workflow benefit is important in high-volume obstetric units. Fewer rescue boluses may reduce demands on anesthesia personnel while improving the patient’s childbirth experience.
Important limitations
This was a single-center, cross-sectional observational study rather than a randomized controlled trial. Assignment to PIEB or continuous infusion was based on clinical practice rather than randomization, creating a risk of selection bias.
No multivariable analysis was performed to adjust for residual confounding. Maternal satisfaction was assessed after delivery and could have been influenced by the overall childbirth experience, mode of delivery, emotional state, or recall bias.
Breakthrough pain was defined by the administration of a physician rescue bolus, which may have varied according to individual clinician judgment.
The study also did not provide detailed neonatal outcomes or evaluate whether the technique affected labor duration, instrumental delivery, cesarean delivery, or long-term maternal satisfaction.
Bottom line
PIEB was associated with higher maternal satisfaction, less breakthrough pain, fewer rescue interventions, and lower local anesthetic and fentanyl consumption than continuous epidural infusion.
The safety profiles were comparable. However, because this was a nonrandomized single-center study, the findings support PIEB as a promising preferred maintenance technique but do not definitively establish its superiority.
Thank you to Cureus for allowing us to summarize this article.