///2014 Abstract Details
2014 Abstract Details2019-07-18T14:34:47-06:00

A randomized controlled trial of epidural volume extension during a combined spinal-epidural technique for labor analgesia

Abstract Number: S-01
Abstract Type: Original Research

Valerie Zaphiratos MSc, MD, FRCPC1 ; Ronald B. George MD, FRCPC2; Bruce Macaulay MD, FRCPC3; Prasad Bolledulla MD, FRCA4; Dolores M. McKeen MD, MSc, FRCPC5

Combined spinal-epidural (CSE) is a popular method for delivering labor analgesia due to rapid onset of profound analgesia, minimal motor blockade, and high patient satisfaction. Epidural volume extension (EVE) involves injection of volume into the epidural space compressing the dural sac, causing cephalad shift of the cerebral spinal fluid (CSF). Our hypothesis is that EVE with 10 ml of normal saline during CSE will increase the anesthetic sensory block height, decrease pain scores, decrease pain scores more rapidly, and decrease motor block compared to performing CSE without EVE. METHODS: An apriori sample size was calculated. We recruited 54 healthy term laboring nulliparous parturients with cervical dilation < 5 cm. Intrathecal analgesia consisted of 2 mg bupivacaine and 10 mcg fentanyl. The subjects were randomly allocated into one of two groups: EVE received 10 ml of normal saline through the Tuohy needle prior to catheter insertion or NEVE where parturients did not receive EVE. Epidural catheters were thread 5 cm into the epidural space and a standard continuous epidural infusion was begun immediately. A blinded researcher assessed sensory dermatome level by blunt pinprick test, analgesia by numeric rating scale (NRS) 0 to 10, and motor blockade with a m-Bromage score 1 to 6 at 2.5 min intervals. The primary outcome measure was the difference in sensory dermatome level as determined by non-traumatic pinprick test. RESULTS: A total of 54 parturients were enrolled. There was no significant difference in demographic criteria, peak dermatome levels at 15 min or 30 min, the time to peak dermatome, the minimum pain score, nor the time to minimum pain score between groups. The number of parturients with a Bromage score less than 6 was less in Group EVE, but this too was not statistically significant. DISCUSSION: To our knowledge, this is the first clinical trial to study the effect of EVE for labor analgesia in parturients. We did not find a significant difference between groups with regards to sensory dermatome level nor pain scores when using EVE. Although there is a trend toward less motor block in Group EVE, this was not statistically significant. Our study demonstrates that EVE does not offer superior analgesia when using a CSE technique for parturients requesting labor analgesia, but any effect on long-term catheter function was not assessed in this study.

References: Cochrane Database Syst Rev 2012 10: CD003401, Anaesthesia 2011; 66: 341-7

SOAP 2014