Evidence map›Paper›PMID 41894130›Full record

ArticleCanadian journal of anaesthesia = Journal canadien d'anesthesie2026

Association of a single low-dose intraoperative magnesium bolus with postoperative opioid requirements: a multicentre retrospective cohort study.

Anastasia P Piersa, Matthew R Smith, Ariel L Mueller, Timothy T Houle, Jamie L Sparling, Lia E Tron, Katarina J Ruscic

Abstract readMulticenter Study
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In one paragraph

Article in Canadian journal of anaesthesia = Journal canadien d'anesthesie, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Anastasia P PiersaDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Matthew R SmithDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Ariel L MuellerDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Timothy T HouleDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Jamie L SparlingDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Lia E TronDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA.
Katarina J RuscicDepartment of Anesthesiology, Massachusetts General Hospital, Mass General Brigham, Boston, MA, USA. kruscic@mgh.harvard.edu.ORCID 0000-0002-5465-3221

Funding

The Impact of Anesthetics on Lymphatic Vessel Contractility and Extracellular Fluid UptakeK08GM155886 · NIGMS · MASSACHUSETTS GENERAL HOSPITAL · PI Katarina J Ruscic · 2024 to 2026
$394k
NIGMS NIH HHS K08 GM155886NIH Extramural Research Support NIGMS K08GM155886NIH Extramural Research Support T32-GM007592Non-US Government Research Support
6 · The paper itself

Abstract

purposeFew studies have investigated the effects of a low-dose, single magnesium bolus on postoperative pain. We sought to evaluate the association between an intraoperative bolus of 2 g magnesium iv and postoperative opioid consumption, with secondary outcomes focused on potential adverse effects.

methodsWe conducted a multicentre retrospective cohort study of adult patients from 14 hospitals in the northeastern USA who had received general anesthesia for elective surgery between 1 January 2018 and 31 December 2022. The primary outcome was total postoperative opioid consumption, defined as intravenous morphine milligram equivalents (IV MME) administered during the postanesthesia care unit (PACU) period. Secondary outcomes included PACU recovery time, levels of consciousness in the PACU, and intraoperative hemodynamics.

resultsAmong 257,206 patient encounters meeting inclusion criteria, 16,233 (6%) received a magnesium bolus. Of those, 95% were given a dose of 2 g iv. In adjusted models, magnesium was associated with increased postoperative opioid consumption (mean difference, 0.9 IV MME; 95% confidence interval [CI], 0.8 to 1.0; P < 0.001). No difference was observed in levels of consciousness in the PACU or in PACU recovery times. After magnesium administration, arterial blood pressure and heart rate decreased, with a gradual return to baseline and with small estimated absolute changes.

conclusionIntraoperative administration of a single bolus of 2 g magnesium iv was associated with a negligible change in postoperative opioid consumption and trivial hemodynamic effects. The results of this study suggest that a single low-dose magnesium bolus may offer no clinical benefit.

Indexed as

Analgesics, OpioidMagnesiumPostoperative PainAgedAnesthesia, GeneralAnesthesia Recovery PeriodCohort StudiesFemaleHumansIntraoperative CareMaleMiddle AgedRetrospective StudiesAnalgesics, OpioidMagnesiumgeneral anesthesiahemodynamicsmagnesiumopioid consumptionpostoperative pain

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.