Use of remifentanil for cesarean section under regional anesthesia: impact on the mother and neonate
Abstract Number: 38
Abstract Type: Original Research
Introduction:Maternal discomfort during cesarean delivery under neuraxial anesthesia is a significant problem for obstetric anesthesiologists.The Royal College of Anaesthetists standards for rate of general anesthesia(GA)conversion of regional anesthesia(RA)is 1% for elective and 3% for emergency cesarean section(CS)(1).In one study,the rate of failure to achieve a pain-free operation was 6% with spinals, 24% with epidural top-up and 18% with combined spinal-epidural(2).A low-dose remifentanil infusion may reduce discomfort during CS under RA.The success rate in reducing GA conversion rate and the optimal effective dose with the best possible maternal and neonatal outcome has not been well investigated.
Methods: We retrospectively analysed data in our obstetric anesthesia data bases in relation to all CS(elective and emergency) under RA with remifentanil supplementation for maternal discomfort or anxiety for a period of 3 years from November 2006 to November 2009.Data collected:patient demographics;indication for CS; anesthetic technique:spinal,epidural,epidural extension or combined spinal epidural; timing and dose of remifentanil used;maternal desaturations; GA conversion; neonatal Apgar scores,resuscitative measures needed and admission to neonatal intensive care unit(NICU);maternal satisfaction with anesthesia.Exclusion:less than 38 weeks gestation;multiple pregnancy;severe maternal or fetal compromise requiring category 1 or 2 CS; use of other sedatives, opioids and hypnotic agents.
Results:After exclusions, 48 parturients remained for analysis. Out of 48,30 were elective and 18 emergency.spinals(34);epidural extensions(12);CSE(2).38 patients had their infusion started before the baby was delivered and 10 after delivery.The range of dosage used was 0.05-0.07µg/kg/min.All had supplemental oxygen,none of them had desaturations<94% and no one required GA for completing the procedure.Maternal satisfaction: Excellent:47(98%);adequate;1(2%);dissatisfied(0%).The neonatal effects in 38 are summarized in the attached table.
Discussion: Intravenous remifentanil infusion as an adjunct to regional anesthesia for Cesarean section appears to provide effective maternal analgesia and anxiolysis.The dosage required is slightly less than previously reported(3).There is no unexpected low neonatal Apgar scores but further randomized controlled studies are required to confirm our data.
References:1)www.rcoa.ac.uk 2)Anaesth2008;63:822-32 3)Int J Obst Anesth2002;11:19