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

• Status: Terminated
• Trial end date: 2012-12-01
• Target enrollment: 0
• Participant gender: All

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.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: CAMC Health System
• Collaborator: Sarah & Pauline Maier Foundation, Inc.
• Treatments: Magnesium Sulfate

Criteria

Inclusion Criteria:

Medicine ICU service patients

• > 18 years old with

• hypomagnesemia defined by a serum magnesium level < 2 mg/dL and the clinical decision by the rounding team to replace with parenteral magnesium sulfate

• must have an available IV line for magnesium infusion that may be used for up to 8 hours

• must have a Foley catheter

Exclusion Criteria:

• renal dysfunction defined by an estimated creatinine clearance (CrCl) < 30 mL/min or have had an average of < 0.5 mL/kg/hr of urine output over the previous 12 hours before the magnesium infusion is to begin

• Subjects must not have received a loop diuretic within the 12 hours prior to magnesium replacement and will further be excluded if they receive these medications during the magnesium replacement and urine collection time period

• Subjects with ostomies or acute diarrhea will be excluded due to the possibility of high gastrointestinal magnesium loss

• Subjects will be excluded if they have a physician order for magnesium sulfate to be infused over a specified time period

• If subjects are expected to be moved out of the ICU within the next 24 hours, they will not be considered for randomization due to potential lack of appropriate urine magnesium collection and follow up

• Each subject may only be enrolled in the study for one occurrence of hypomagnesemia