Programmed intermittent epidural boluses (pieb) for labor analgesia: study of the sensor block and effects on maternal motor function

Background. Programmed intermittent epidural boluses (PIEB) technique is a promising approach that demonstrates certain advantages over traditional techniques of epidural analgesia. We compared the dynamics of the sensory block of PIEB + parturient-controlled epidural analgesia (PCEA) with continuous epidural infusion (CEI) + PCEA for maintenance labor analgesia and the incidence of motor block (MB) in women who received PIEB or traditional techniques. Methods. A total of 165 subjects were studied. All parturients were divided into five groups: manual boluses, PCEA, PCEA + CEI, PIEB + PCEA; levobupivacaine 0.25 mg/mL; 1.25 mg/mL; 0.625 mg/mL. The level of the MB was evaluated by the classic Bromage scale (0-1-2-3). The level of the sensor block was evaluated by the pin-prick test. Results. MB was reported in 80% in group 1 120 min after analgesia, 78% and 52% in groups 2 and 3 at the 150th min (p 0.001); in group 4, the MB frequency was 6% 15 min after the start and was increasing to 40% at full cervical dilation (p 0.001). In group 5, the relative MB frequency did not exceed 10% at the 120th min and was 0% at full cervical dilation (p 0.00001). The results indicate that in the PIEB group, the level of sensory block in patients was higher 15 min after the start of analgesia and remained so until the end of the observation period [median PIEB Th5 versus Th8 in the CEI group, (p 0.0004)]. Conclusions. PIEB + PCEA technique maintained a consistently high level of sensor block throughout the study compared to PCEA + CEI, which ensured effective analgesia in the first and second stages of labor with minimal MB.