Intraoperative magnesium administration does not improve neurocognitive function after cardiac surgery.

Published

Journal Article

BACKGROUND AND PURPOSE: Neurocognitive decline occurs frequently after cardiac surgery and persists in a significant number of patients. Magnesium is thought to provide neuroprotection by preservation of cellular energy metabolism, blockade of the N-methyl-D-aspartate receptor, diminution of the inflammatory response, and inhibition of platelet activation. We therefore hypothesized that intraoperative magnesium administration would decrease postoperative cognitive impairment. METHODS: After approval by the Duke University Health System Institutional Review Board, 389 patients undergoing cardiac surgery were enrolled in this prospective, randomized, double-blind, placebo-controlled clinical trial. Subjects were randomized to receive magnesium as a 50 mg/kg bolus followed by another 50 mg/kg infusion for 3 hours or placebo bolus and infusion. Cognitive function was assessed preoperatively and again at 6 weeks postoperatively using a standardized test battery. Mean CD11b fluorescence and percentage of platelets expressing CD62P, which are markers of leukocyte and platelet activation, respectively, were assessed by flow cytometry as a secondary outcome. The effect of magnesium on postoperative cognition was tested using multivariable regression modeling, adjusting for age, years of education, baseline cognition, sex, race, and weight. RESULTS: Among the 389 allocated subjects (magnesium: n=198; placebo: n=191), the incidence of cognitive deficit in the magnesium group was 44.4% compared with 44.9% in the placebo group (P=0.93). The cognitive change score and platelet and leukocyte activation were also not different between the groups. Multivariable analysis revealed a marginal interaction between treatment group and weight such that heavier subjects receiving magnesium were less likely to have cognitive deficit (P=0.06). CONCLUSIONS: Magnesium administered intravenously during cardiac surgery does not reduce postoperative cognitive dysfunction. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00041392.

Full Text

Duke Authors

Cited Authors

  • Mathew, JP; White, WD; Schinderle, DB; Podgoreanu, MV; Berger, M; Milano, CA; Laskowitz, DT; Stafford-Smith, M; Blumenthal, JA; Newman, MF; Neurologic Outcome Research Group (NORG) of The Duke Heart Center,

Published Date

  • December 2013

Published In

Volume / Issue

  • 44 / 12

Start / End Page

  • 3407 - 3413

PubMed ID

  • 24105697

Pubmed Central ID

  • 24105697

Electronic International Standard Serial Number (EISSN)

  • 1524-4628

Digital Object Identifier (DOI)

  • 10.1161/STROKEAHA.113.002703

Language

  • eng

Conference Location

  • United States