title: A comparison of a basal infusion with automated mandatory boluses in parturient-controlled epidural analgesia during labor.
abstract: BACKGROUND
  The use of parturient-controlled epidural analgesia (PCEA) with a basal infusion is commonly used in laboring women. We compared a novel approach of providing basal intermittent boluses concurrently with PCEA: PCEA plus automated mandatory boluses (PCEA+AMB) versus PCEA plus basal continuous infusion (PCEA+BCI). We hypothesized that epidural local anesthetic consumption would be lower if basal intermittent boluses were used instead of a basal infusion.
  
  
  METHODS
  We randomized 42 healthy parturients in early labor to receive 0.1% ropivacaine + fentanyl 2 microg/mL either via PCEA+BCI (n = 21,bolus 5 mL, lockout 10 min, basal infusion 5 mL/h) or via PCEA+AMB (n = 21, patient-activated bolus of 5 mL, lockout 10 min, basal automated boluses of 5 mL/h [omitted if a patient-activated bolus was successfully administered in the last 1 h]) after successful induction of combined spinal epidural analgesia.
  
  
  RESULTS
  We found a reduction in the hourly consumption of ropivacaine with PCEA+AMB, i.e., the primary outcome measure (mean = 6.5 mL, sd = 3.4 in the PCEA+AMB group vs 7.5 mL, sd = 2.0 PCEA+BCI group, P = 0.011). A larger proportion of parturients in the PCEA+AMB group did not self-bolus (6/21 vs 1/21 in PCEA+BCI, P = 0.03). The time to the first self-bolus after combined spinal epidural was longer in the PCEA+AMB group (mean survival time 315 min vs 190 min in PCEA+BCI group, P = 0.04 by log rank test). There was no difference in pain scores or side effects.
  
  
  CONCLUSIONS
  Our study showed that PCEA+AMB reduced analgesic consumption and could be useful as the mode of maintenance for epidural analgesia.
authors.affiliation: Department of Women's Anaesthesia, KK Women's and Children's Hospital, Singapore. athsia@kkh.com.sg
authors.forename: Alex T
authors.initials: AT
authors.lastname: Sia
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Lim
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ocampo
mesh_terms: D000328:Adult; D000577:Amides / Q000008:administration & dosage; D015360:Analgesia, Epidural / Q000379:methods*; D016362:Analgesia, Obstetrical / Q000379:methods*; D016058:Analgesia, Patient-Controlled / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D006801:Humans; D048949:Labor Pain / Q000188:drug therapy*; D007743:Labor, Obstetric; D011247:Pregnancy; D000077212:Ropivacaine; D013997:Time Factors
chemical_list: D000577:Amides; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D000077212:Ropivacaine; D005283:Fentanyl