Pharmacokinetics of Magnesium Bolus Therapy in Cardiothoracic Surgery

Peter Biesenbach, Johan Mårtensson, Luca Lucchetta, Ravi Bangia, Jessica Fairley, Irmelin Jansen, George Matalanis, Rinaldo Bellomo

Research output: Contribution to journalArticleResearchpeer-review

15 Citations (Scopus)

Abstract

Objective: To investigate the pharmacokinetics of a 20 mmol magnesium bolus in regards to serum and urinary magnesium concentration, volume of distribution, and half-life. Design: Prospective, experimental study. Setting: A university-affiliated teaching hospital. Participants: Twenty consecutive cardiac surgery patients treated with magnesium bolus therapy for prevention of arrhythmia. Interventions: A 20-mmol bolus of magnesium sulfate was administered intravenously. Measurements and Main Results: Median magnesium levels increased from 1.04 (interquartile range 0.94-1.23) mmol/L to 1.72 (1.57-2.14) mmol/L after 60 minutes of magnesium infusion (p < 0.001) but decreased to 1.27 (1.21-1.36) and 1.16 (1.11-1.21) mmol/L after 6 and 12 hours, respectively. Urinary magnesium concentration increased from 6.3 (4.2-14.5) mmol/L to 19.1 (7.4-34.5) mmol/L after 60 minutes (p < 0.001), followed by 22.7 (18.4-36.7) and 15 (8.4-19.7) mmol/L after 6 and 12 hours, respectively. Over the 12-hour observation period, the cumulative urinary magnesium excretion was 19.1 mmol (95.5% of the dose given). The median magnesium clearance was 10 (4.7-15.8) mL/min and increased to 14.9 (3.8-20.7; p = 0.934) mL/min at 60 minutes. The estimated volume of distribution was 0.31 (0.28-0.34) L/kg. Conclusion: Magnesium bolus therapy after cardiac surgery leads to a significant but short-lived increase of magnesium serum concentration due to renal excretion and distribution, and the magnesium balance is neutral after 12 hours.

Original languageEnglish
Pages (from-to)1289-1294
Number of pages6
JournalJournal of Cardiothoracic and Vascular Anesthesia
Volume32
Issue number3
DOIs
Publication statusPublished - Jun 2018

Keywords

  • arrhythmia
  • atrial flutter
  • cardiac surgery
  • intensive care
  • magnesium
  • pharmacokinetics

Cite this