Prevalence of Hypomagnesemia in ICU Patients at a Tertiary Care Center: A Prospective Observational Study

Abstract

BACKGROUND Magnesium, the fourth most abundant cation in the human body, plays a crucial role in enzymatic activity, neurochemical transmission, and muscular excitability. Hypomagnesemia in critically ill patients has been associated with neuromuscular dysfunction, cardiovascular complications, metabolic disturbances, and increased morbidity. This study aims to determine the prevalence of hypomagnesemia in critically ill patients and evaluate its impact on disease severity, length of ICU stay, ventilator dependency, and mortality. METHODS This prospective observational study was conducted in the ICU of a tertiary care hospital after obtaining institutional ethical clearance. A total of 100 critically ill patients aged ≥45 years were enrolled after providing written informed consent. Serum magnesium levels, along with key biochemical markers including serum calcium, serum potassium, procalcitonin, creatinine, blood urea nitrogen (BUN), serum albumin, and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, were documented at admission. Patients with serum magnesium levels >2.6 mg/dL were excluded. The primary outcome was the prevalence of hypomagnesemia (<1.7 mg/dL). Secondary outcomes included ICU stay duration, ventilator days, and 28-day mortality. Statistical analysis was conducted using paired and unpaired t-tests via GraphPad (Dotmatics, Boston, Massachusetts, United States/Insight Venture Management, LLC, New York, New York, United States). RESULTS Among 100 patients, 24% had hypomagnesemia (Group A), while 72% had normal magnesium levels (Group B). The mean age in Group A was significantly higher (64.8±6.2 years) compared to Group B (59.2±4.9 years) (p<0.001), indicating an increased prevalence in older patients. Group A showed a slightly higher APACHE II score compared to Group B, signifying increased disease severity. A statistically significant association was found between hypomagnesemia and hypocalcemia (66.7% vs. 26.4%; p<0.001), whereas no clear association was observed between hypomagnesemia and hypokalemia or hypoalbuminemia. Chronic obstructive pulmonary disease (COPD) was significantly more prevalent in Group A than in Group B (p=0.049). Patients with hypomagnesemia had a longer duration of mechanical ventilation (6.8±2.1 vs. 5.9±1.9 days; p<0.05) and prolonged ICU stay (8.36±3.62 vs. 6.8±2.43 days; p<0.05). However, no statistically significant difference in 28-day mortality was observed between the groups (p=0.89). CONCLUSION Hypomagnesemia is highly prevalent among critically ill patients, particularly in older individuals, and is associated with increased disease severity, prolonged ventilator dependency, and extended ICU stay. A strong correlation between hypomagnesemia and hypocalcemia was observed, suggesting the need for comprehensive electrolyte monitoring in critically ill patients. Although hypomagnesemia did not directly influence short-term mortality, its impact on disease progression and ICU morbidity necessitates further investigation. Early detection and timely magnesium supplementation may improve patient outcomes. Larger multi-center studies are warranted to explore the therapeutic implications of magnesium correction in ICU settings.