Automated intermittent epidural boluses improve analgesia induced by intrathecal fentanyl during labour

Can J Anaesth. 2004 Jun-Jul;51(6):581-5. doi: 10.1007/BF03018402.

Abstract

Purpose: We compared the efficacy of epidural continual intermittent boluses (CIB) with a continuous epidural infusion (CEI) in prolonging labour analgesia induced by the combined spinal epidural (CSE) technique.

Methods: CSE was instituted in 42 nulliparous parturients at the L3 to 4 level with intrathecal (IT) fentanyl 25 micro g followed by an epidural test dose of 3 mL of 1.5% lidocaine. These parturients were then randomly assigned to receive either epidural CIB (n = 21) or CEI (n = 21) with 0.1% ropivacaine and fentanyl 2 micro g x mL(-1). For the CIB, 5 mL boluses were given hourly, with the first bolus 30 min postinduction. CEI at the rate of 5 mL.hr(-1) was initiated in the minute after CSE. The duration of analgesia, pain score, degree of sensorimotor block were compared.

Results: From Kaplan Meier survival analysis, the duration of analgesia was significantly longer in CIB (mean survival time 239 +/- SD 24 min vs 181 +/- 17, P < 0.05 using log rank test). During the first three hours postblock, the median sensory block to cold was higher in CIB (P < 0.05, Mann U Whitney test) but no difference in blood pressure was detected [P > 0.05, repeated measure analysis of variance (RMANOVA)]. The serial pain scores were lower in the CIB (P < 0.05, RMANOVA).

Conclusion: CIB prolonged the duration and improved the quality of analgesia. CIB could have resulted in an improved spread of analgesics in the epidural space or encouraged a direct passage of infusate into the IT space. This could have also rendered a higher sensory block to cold in the CIB group. CIB is a good alternative to CEI for the maintenance of epidural analgesia after CSE.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Amides / administration & dosage
  • Analgesia, Epidural / instrumentation*
  • Analgesia, Obstetrical*
  • Analgesics, Opioid / administration & dosage*
  • Analysis of Variance
  • Anesthesia, Obstetrical
  • Anesthesia, Spinal
  • Anesthetics, Local / administration & dosage
  • Cold Temperature
  • Female
  • Fentanyl / administration & dosage*
  • Humans
  • Infusion Pumps*
  • Injections, Spinal
  • Labor, Obstetric*
  • Pain / prevention & control
  • Pain Measurement
  • Pregnancy
  • Ropivacaine
  • Sensation / drug effects
  • Statistics, Nonparametric
  • Survival Analysis
  • Time Factors

Substances

  • Amides
  • Analgesics, Opioid
  • Anesthetics, Local
  • Ropivacaine
  • Fentanyl