Comparison of ultra-low, low and high concentration local anaesthetic for labour epidural analgesia: a systematic review and network meta-analysis

Halliday, L., Kinsella, M., Shaw, M., Cheyne, J., Nelson, N.M. and Kearns, R. J. (2022) Comparison of ultra-low, low and high concentration local anaesthetic for labour epidural analgesia: a systematic review and network meta-analysis. Anaesthesia, 77(8), pp. 910-918. (doi: 10.1111/anae.15756) (PMID:35607864)

Abstract

Lumbar epidural is the gold standard for labour analgesia. Low concentrations of local anaesthetic are recommended. This network meta-analysis investigated whether further reducing the concentration of local anaesthetic can improve maternal and neonatal outcomes without compromising analgesia. We conducted a systematic search of relevant databases for randomised controlled trials comparing high (>0.1%), low (>0.08% to ≤0.1%) or ultra-low (≤0.08%) concentration local anaesthetic (bupivacaine or equivalent) for labour epidural. Outcomes included mode of delivery, duration of labour and maternal/neonatal outcomes. Bayesian network meta-analysis with random-effects modelling was used to calculate odds ratios or weighted mean differences and 95% credible intervals. A total of 32 studies met inclusion criteria (3665 women). The total dose of local anaesthetic received increased as the concentration increased; ultra-low compared with low (weighted mean difference −14.96 mg, 95% credible interval [−28.38 to −1.00]) and low compared with high groups (weighted mean difference −14.99 [−28.79 to −2.04]), though there was no difference in the number of rescue top-ups administered between the groups. Compared with high concentration, ultra-low concentration local anaesthetic was associated with increased likelihood of spontaneous vaginal delivery (OR 1.46 [1.18 to 1.86]), reduced motor block (Bromage score >0; OR 0.32 [0.18 to 0.54]) and reduced duration of second stage of labour (weighted mean difference −13.02 min [−21.54 to −4.77]). Compared with low, ultra-low concentration local anaesthetic had similar estimates for duration of second stage of labour (weighted mean difference −1.92 min [−14.35 to 10.20]); spontaneous vaginal delivery (OR 1.07 [0.75 to 1.56]; assisted vaginal delivery (OR 1.35 [0.75 to 2.26]); caesarean section (OR 0.76 [0.49 to 1.22]); pain (scale 1–100, weighted mean difference −5.44 [−16.75 to 5.93]); and maternal satisfaction. Although a lower risk of an Apgar score < 7 at 1 min (OR 0.43 [0.15 to 0.79]) was reported for ultra-low compared with low concentration, this was not sustained at 5 min (OR 0.12 [0.00 to 2.10]). Ultra-low concentration local anaesthetic for labour epidural achieves similar or better maternal and neonatal outcomes as low and high concentration, but with reduced local anaesthetic consumption.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kearns, Dr Rachel and Kinsella, Dr Michael and Halliday, Dr Lucy and Shaw, Dr Martin
• Authors: Halliday, L., Kinsella, M., Shaw, M., Cheyne, J., Nelson, N.M., and Kearns, R. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Anaesthesia
• Publisher: Wiley
• ISSN: 0003-2409
• ISSN (Online): 1365-2044
• Published Online: 24 May 2022
• Copyright Holders: Copyright © 2022 The Authors.
• First Published: First published in Anaesthesia 77(8): 910-918
• Publisher Policy: Reproduced under a Creative Commons license