Does programmed intermittent epidural bolus improve childbirth conditions of nulliparous women compared with patient-controlled epidural analgesia?: A multicentre, randomised, controlled, triple-blind study

Abstract

BACKGROUNDEpidural analgesia may change the mechanics of childbirth. These changes are related to the concentration of the local anaesthetic used epidurally but probably also to its mode of delivery into the epidural space.OBJECTIVETo determine whether the administration of programmed intermittent epidural boluses (PIEB) improves the mechanics of second-stage labour compared with patient-controlled epidural analgesia (PCEA) with a background infusion.DESIGNA randomised, controlled, triple-blind study.SETTINGMulticentre study including four level III maternity units, January 2014 until June 2016.PATIENTSA total of 298 nulliparous patients in spontaneous labour were randomised to a PIEB or PCEA group.INTERVENTIONAfter epidural initiation with 15ml of 0.1% levobupivacaine containing 10μg of sufentanil, patients received either an hourly bolus of 8ml (PIEB) or a continuous rate infusion of 8mlh-1 (PCEA): the drug mixture used was levobupivacaine 0.1% and sufentanil 0.36μgml-1.MAIN OUTCOME MEASURESThe primary outcome was a composite endpoint of objective labour events: a posterior occiput position in the second stage, an occiput position at birth, waiting time at full cervical dilatation before active maternal pushing more than 3h, maternal active pushing duration more than 40min, and foetal heart rate alterations. Vaginal instrumental delivery rates, analgesia and motor blockade scores were also recorded.RESULTSFrom the 298 patients randomised, data from 249 (124 PIEB, 125 PCEA) were analysed. No difference was found in the primary outcome: 48.0% (PIEB) and 45.5% (PCEA) of patients, P=0.70. In addition, no difference was observed between the groups for each of the individual events of the composite endpoint, nor in the instrumental vaginal delivery rate, nor in the degree of motor blockade. Despite an equivalent volume of medication in the groups, a significantly higher analgesia score at full dilatation was observed in the PIEB group, odds-ratio=1.9 (95% confidence interval, 1.0 to 3.5), P=0.04.CONCLUSIONThe mechanics of the second stage did not differ whether PIEB or PCEA was used. Analgesic conditions appeared to be superior with PIEB, especially at full dilation.