Effect of Magnesium Sulfate Infusion Rate on Magnesium Retention in Critically Ill Patients

Summary

Hypomagnesemia (low magnesium) is an electrolyte imbalance commonly found in up to 65% of critically ill patients. Possible consequences of hypomagnesemia include neuromuscular and neurologic dysfunction, heart arrhythmias, and alterations in other electrolytes. Data has shown that critically ill patients with hypomagnesemia have a significantly higher mortality rate than patients with a normal magnesium level. The most simple and commonly used test to diagnose hypomagnesemia is a serum magnesium level. Based on the magnesium level and symptoms of hypomagnesemia, patients may be replaced with either oral or intravenous (IV) magnesium. When replacing magnesium via the IV route, approximately half of the dose is retained by the body while the remainder is excreted in the urine. The low retention rate is due to the slow uptake of magnesium by cells and decreased magnesium reabsorption by the kidneys in response to the delivery of a large concentration of magnesium. The purpose of this study is to determine whether an eight hour compared to a four hour infusion of IV magnesium sulfate results in a greater retention of the magnesium dose.

Timeline

Start

2011-04

Primary completion

2012-04

Completion

2012-12

Publications

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• Background Broeren MA, Geerdink EA, Vader HL, van den Wall Bake AW. Hypomagnesemia induced by several proton-pump inhibitors. Ann Intern Med. 2009 Nov 17;151(10):755-6. doi: 10.7326/0003-4819-151-10-200911170-00016. No abstract available.
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• Background CHESLEY LC, TEPPER I. Some effects of magnesium loading upon renal excretion of magnesium and certain other electrolytes. J Clin Invest. 1958 Oct;37(10):1362-72. doi: 10.1172/JCI103726. No abstract available.
• Background BARKER ES, ELKINTON JR, CLARK JK. Studies of the renal excretion of magnesium in man. J Clin Invest. 1959 Oct;38(10 Pt 1-2):1733-45. doi: 10.1172/JCI103952. No abstract available.
• Background Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. doi: 10.1159/000180580.
• Background Agus ZS. Hypomagnesemia. J Am Soc Nephrol. 1999 Jul;10(7):1616-22. doi: 10.1681/ASN.V1071616. No abstract available.

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