International Journal of Research in Medical Sciences | April 2022 | Vol 10 | Issue 4 Page 801 International Journal of Research in Medical Sciences Onah DU et al. Int J Res Med Sci. 2022 Apr;10(4):801-807 www.msjonline.org pISSN 2320-6071 | eISSN 2320-6012 Original Research Article Effect of intrathecal midazolam on single dose morphine-bupivacaine co-mixture for spinal analgesia in labour Damian U. Onah, Alfred T. Aggo, Longinus N. Ebirim* INTRODUCTION Epidural services have become the gold standard for labour analgesia in many parts of the world but spinal analgesia is beginning to gain popularity especially in the developing countries. 1 However, owing to its comparatively short duration of action, a repeat dose or supplemental analgesia may be required. Addition of adjuvants to local anaesthetics administered intrathecally prolongs the duration of analgesia. 2 Such adjuvants include fentanyl, morphine, clonidine, dexmedetomidine and midazolam. Intra-thecal midazolam on its own is not known to provide significant labour analgesia. However, as an adjuvant, it has been shown to be a ‘promising’ option for decreasing labour pain. 2 Its impact on intra-thecal bupivacaine and morphine mixture is yet to be sufficiently evaluated especially in our sub-region. Therefore, the aim of this study was to evaluate the effects of intra-thecal midazolam (2.0 mg) on intra-thecal labour analgesia from a mixture of bupivacaine (2.5 mg) and morphine (150 mcg). Department of Anaesthesiology, University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State, Nigeria Received: 17 February 2022 Revised: 07 March 2022 Accepted: 19 March 2022 *Correspondence: Dr. Longinus N. Ebirim, E-mail: ginebirim@yahoo.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Background: When spinal analgesia is used for relief of labour pain, a major challenge has been how to extend its duration without increasing the associated adverse effects. The aim of this study was to evaluate the effect of intra- thecal midazolam on pain relief by low dose bupivacaine and morphine mixture administered intrathecally to women in labour. Methods: 160 labouring women, aged between 18 and 40 years gave consent and enrolled for this comparative study. The women were randomly allocated into two equal groups, MBM and BM. Group MBM received intrathecal 2.0 mg midazolam, 2.5 mg bupivacaine and 150 mcg morphine. Group BM received intra-thecal 2.5 mg bupivacaine and 150 mcg morphine. An epidural bolus dose of bupivacaine 10 mg plus fentanyl 25 mcg was given whenever rescue analgesia was needed. Foeto-maternal parameters, were assessed and recorded. Results: Duration of effective spinal analgesia was significantly longer in group MBM than in group BM, p=0.0001. More participants in group BM had epidural rescue analgesia compared to group MBM, p=0.001. More participants in group MBM had adequate spinal analgesia till delivery compared to group BM, p=0.001. All the participants in both groups were able to ambulate without support after 30 minutes following the injection of spinal drugs. Nausea and vomiting occurred less commonly in group MBM than in BM, p=0.006. Conclusions: Addition of midazolam to bupivacaine-morphine co-mixture significantly prolonged the duration of spinal analgesia without affecting ambulation or causing any considerable maternal or neonatal adverse effect. Keywords: Labour, Intrathecal analgesia, Bupivacaine, Morphine, Midazolam DOI: https://dx.doi.org/10.18203/2320-6012.ijrms20220968