A prospective observational study to identify the effectiveness of intravenous magnesium replacement in an intensive care setting

Abstract

Background and Aims: To estimate the incidence of hypomagnesemia and identify the effectiveness of a calculated dose of intravenous magnesium sulfate (MgSO 4) in correction of hypomagnesemia and its relationship with renal function in critically ill patients. Material and Methods: All patients admitted in the adult intensive care unit were enrolled in the study and magnesium levels were monitored. Patients with serum magnesium levels <1.7 mg/dL received calculated doses of Intravenous MgSO 4. The average rise in serum magnesium levels per gram of MgSO 4 administered was calculated and relationship with estimated glomerular filtration rate (eGFR) was identified. Results: In total, 27.27% of patients admitted in our intensive care unit had an incidence of hypomagnesemia. The average rise of serum magnesium levels in patients with hypomagnesemia was 0.13 (±0.05) mg/dl. The average rise of serum magnesium levels was 0.10 (±0.04) mg/dL in patients with eGFR ≥ 90 mL/min/1.73 m 2 and 0.15 (± 0.05) mg/dL in patients with eGFR < 90 mL/min/1.73 m 2. This difference between the two groups (P-value = 0.002) and the trend of increasing average rise in serum magnesium levels with declining eGFR values (P-value = 0.013) were both statistically significant. Conclusion: Incidence of hypomagnesemia in the critically ill population is around 27.27%. Intravenous administration of 1 g of MgSO 4 results in a rise of serum magnesium levels by 0.1 mg/dL in patients with normal eGFR and around 0.15 mg/dL in patients with eGFR values between 30 and 89 mL/min/1.73 m 2.