Programmed intermittent epidural bolus regimen vs continuous epidural infusion: a retrospective study of motor block...

Use of a programmed intermittent epidural bolus (PIEB) regimen during labour is associated with several benefits over a continuous epidural infusion (CEI), including reduced local anaesthetic consumption and reduced risk of motor block. We hypothesise that the benefits of a PIEB regimen may vary according to the Robson Ten Group Classification System (TGCS). The aim of this study was to determine if introduction of a PIEB regimen was associated with reduced incidence of motor block. We also wished to examine changes in obstetric outcomes following PIEB introduction across the Robson TGCS.

This was a single-centre retrospective cohort study. Data were collected over two three-month periods before and after PIEB introduction. The primary outcome was the incidence of motor block. Maternal and obstetric outcomes across Robson Groups 1-4 were analysed.

Introduction of PIEB was associated with reduced incidence of motor block (28.4% (95% CI 25.7% to 31.3%) vs 22.4%, (95% CI 19.9% to 25.2%), difference 5.9% (95% CI 1.0% to 21.1%), P=0.003), with no association with changes in rates of caesarean section, operative vaginal delivery or other obstetric outcomes. Use of a PIEB regimen was associated with reduced incidence of motor block in Robson Group 4a (20.3% (16.0%, 28.0%) vs 12.0%, (7.6%, 16.4%), difference 9.9% (95% CI -17.4% to -2.4%) P=0.009). There were no significant changes in other outcomes assessed across Robson TGCS.

Introduction of PIEB for maintenance of labour analgesia was associated with reduced incidence of motor block in our institution compared with CEI. Presenting results according to Robson's TGCS in future studies may allow better elucidation of the impact of neuraxial analgesia on maternal and obstetric outcomes.