title: A randomized comparison of automated intermittent mandatory boluses with a basal infusion in combination with patient-controlled epidural analgesia for labor and delivery.
abstract: BACKGROUND
  Automated mandatory boluses (AMB), when used in place of a continuous basal infusion, have been shown to reduce overall local anesthetic consumption without compromising analgesic efficacy in patient-controlled epidural analgesia (PCEA). We hypothesized that our PCEA+AMB regimen could result in a reduction of breakthrough pain requiring epidural supplementation in comparison with PCEA with a basal infusion (PCEA+BI).
  
  
  METHODS
  We recruited sixty-two healthy ASA I nulliparous parturients in early labor. The parturients were randomized to receive 0.1% ropivacaine+fentanyl 2 μg/mL either via PCEA+BI (PCEA with basal continuous infusion of 5mL/h) or PCEA+AMB (PCEA with AMB of 5 mL every hour instead of a basal infusion) immediately following successful induction of combined spinal-epidural (CSE) analgesia. Block characteristics, incidence of breakthrough pain requiring epidural supplementation, side effects, obstetric outcomes, Apgar scores and overall maternal satisfaction with analgesia were noted.
  
  
  RESULTS
  The time-weighted hourly consumption of ropivacaine (PCEA and clinician supplementation for breakthrough pain) was significantly lower in the PCEA+AMB group (mean=7.6 mL, SD 3.2) compared to the PCEA+BI group (mean=9.3 mL, SD 2.5; P<0.001). The mean time to first PCEA self-bolus following CSE was significantly longer in the PCEA+AMB group compared to the PCEA+BI group (268 min vs. 104 min; P<0.001). Parturients in Group PCEA+AMB also gave higher satisfaction scores. The incidence of breakthrough pain was similar in both groups.
  
  
  CONCLUSIONS
  PCEA+AMB, when compared to PCEA+BI, confers greater patient satisfaction and a longer duration of effective analgesia after CSE despite reduced analgesic consumption.
authors.affiliation: Department of Women's Anaesthesia, KK Women's and Children's Hospital, Singapore.
authors.forename: S
authors.initials: S
authors.lastname: Leo
authors.forename: C E
authors.initials: CE
authors.lastname: Ocampo
authors.forename: Y
authors.initials: Y
authors.lastname: Lim
authors.forename: A T
authors.initials: AT
authors.lastname: Sia
mesh_terms: D000328:Adult; D015360:Analgesia, Epidural / Q000009:adverse effects / Q000379:methods*; D016362:Analgesia, Obstetrical / Q000009:adverse effects / Q000379:methods*; D016058:Analgesia, Patient-Controlled / Q000009:adverse effects / Q000379:methods*; D000775:Anesthesia, Spinal / Q000009:adverse effects / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage; D001331:Automation; D001794:Blood Pressure / Q000187:drug effects; D036861:Delivery, Obstetric; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006340:Heart Rate, Fetal / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D007260:Infusion Pumps; D053208:Kaplan-Meier Estimate; D007743:Labor, Obstetric; D010147:Pain Measurement; D011247:Pregnancy; D011256:Pregnancy Outcome; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local