Effect of pH-adjustment of bupivacaine on onset and duration of epidural analgesia in parturients.

Journal Article (Journal Article)

Previous studies have reported that elevation of the pH of local anaesthetics is associated with enhanced quality and duration of block. This study investigated the effect, on time to onset and duration of analgesia, of pH adjustment of 0.25 per cent bupivacaine immediately prior to injection into the epidural space in parturients. Addition of 0.1 ml of 8.4 per cent sodium bicarbonate to 20 ml of 0.25 per cent bupivacaine consistently raised the pH of the local anaesthetic from 5.65 to 7.26 (mean values). Thirty parturients received an epidural injection of 8 ml of pH-adjusted 0.25 per cent bupivacaine and a control group of 30 parturients received 8 ml of the standard commercial preparation of 0.25 per cent bupivacaine. Elevation of the pH of the local anaesthetic significantly increased the speed of onset of analgesia from 6.0 minutes to 3.2 minutes and the duration of analgesia was significantly lengthened from 79.4 minutes to 96.5 minutes. There was no significant influence on time to peak effect, nor on mean maternal plasma levels of bupivacaine.

Full Text

Duke Authors

Cited Authors

  • McMorland, GH; Douglas, MJ; Jeffery, WK; Ross, PL; Axelson, JE; Kim, JH; Gambling, DR; Robertson, K

Published Date

  • September 1986

Published In

Volume / Issue

  • 33 / 5

Start / End Page

  • 537 - 541

PubMed ID

  • 3021299

International Standard Serial Number (ISSN)

  • 0008-2856

Digital Object Identifier (DOI)

  • 10.1007/BF03014257


  • eng

Conference Location

  • Canada