Clinical Research Directory

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