A Comparison of Minimum Local Anesthetic Volumes and Doses of Epidural Bupivacaine (0.125% w/v and 0.25% w/v) for Analgesia in Labor
- 1 February 2007
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Anesthesia & Analgesia
- Vol. 104 (2), 412-415
- https://doi.org/10.1213/01.ane.0000252458.20912.ef
Abstract
In this study we sought to determine and compare the minimum local anesthetic volumes (MLAV) and doses (MLAD) of two concentrations of bupivacaine for epidural pain relief in labor, and to quantify the effect on dose. Eighty women were randomized in a double-blind manner to receive a first bolus of either plain bupivacaine 0.125% (w/v) or 0.25% (w/v). The arbitrary starting volume was 15 mL. Subsequent volumes were decided by sequential allocation according to analgesic efficacy. A visual analog pain score < or =10 (0-100) within 30 min, indicated effective analgesia. The next woman received a decrement of 2 mL. A failure of the visual analog pain score to reach < or =10 was followed by a 2 mL increment for the next woman. Using the formula of Dixon and Massey, MLAV and MLAD, with 95% confidence intervals (CI) were calculated for each concentration. MLAV was 13.6 mL (95% CI 12.4-14.8), with bupivacaine 0.125% (w/v), and 9.2 mL (95% CI 6.9-11.5) with bupivacaine 0.25% (w/v). The difference was highly significant (P = 0.002). MLAD for these volumes were 17.0 mg (95% CI 15.5-18.5), and 23.1 mg (17.2-28.9), respectively (P = 0.045). Bupivacaine 0.125% (w/v) when compared with 0.25% (w/v) produced equivalent analgesia with a 50% increase in volume, but with a 25% reduction in dose. Any reduction in dose, without loss of efficacy, reduces risk of toxicity and improves safety.This publication has 11 references indexed in Scilit:
- Up-down studies: responding to dosing!International Journal of Obstetric Anesthesia, 2006
- Minimum Analgesic Dose of Epidural Sufentanil for First-stage Labor AnalgesiaAnesthesiology, 2001
- Epidural ropivacaine with fentanyl following major gynaecological surgery: the effect of volume and concentration on pain relief and motor impairmentBritish Journal of Anaesthesia, 2000
- Comparison of 0.25% S(-)-bupivacaine with 0.25% RS-bupivacaine for epidural analgesia in labourBritish Journal of Anaesthesia, 1999
- Effects of Diluent Volume of a Single Dose of Epidural Bupivacaine in Parturients During the First Stage of LaborRegional Anesthesia & Pain Medicine, 1998
- Minimum local analgesic concentration of extradural bupivacaine increases with progression of labourBritish Journal of Anaesthesia, 1998
- The effect of patient position and obesity on the spread of epidural analgesiaInternational Journal of Obstetric Anesthesia, 1993
- The Addition of Fentanyl to Epidural Bupivacaine in First Stage LabourAnaesthesia and Intensive Care, 1990
- Continuous infusion epidural analgesia in obstetricsAnaesthesia, 1986
- 0·125% bupivacaine for obstetric analgesia?Anaesthesia, 1978