Prevalence of Electrolyte Imbalances in Critically Ill Medical Intensive Care Unit Patients and Their Association With Clinical Outcomes

Background Electrolyte disturbances are frequent in critically ill patients and may contribute to poor outcomes. Despite routine monitoring in intensive care units (ICUs), their prevalence and impact on prognosis among medical ICU populations remain incompletely defined. This study aimed to determine the prevalence of electrolyte imbalances in critically ill medical ICU patients and evaluate their association with clinical outcomes. Methodology This cross-sectional, analytical study was conducted at the General Medicine Department, Farooq Hospital, Lahore/Avicenna Medical College, Lahore, Pakistan, from January 2024 to December 2024. The study included 355 adult patients admitted to the medical ICU. Demographic, clinical, and laboratory data were recorded. Electrolyte abnormalities were defined using standard cutoffs for sodium, potassium, calcium, magnesium, and phosphate. Outcomes included ICU mortality, hospital mortality, length of ICU stay, ventilator days, arrhythmias, and acute kidney injury. Results Electrolyte imbalances were observed in 278 (78.3%) patients. The most common disturbances were hyponatremia in 122 (34.4%), hypokalemia in 103 (29.0%), and hypocalcemia in 95 (26.7%) patients. Hypernatremia was present in 51 (14.4%) and hyperkalemia in 44 (12.4%) patients, both strongly associated with mortality. Among the 157 (44.2%) patients with ≥2 electrolyte abnormalities, 98 (62.2%) had significantly higher ICU mortality compared to 63 (32.1%) in those with fewer abnormalities (p < 0.001). These patients also had longer ICU stays (median = 9 vs. 6 days, p = 0.02) and increased complications. On multivariate analysis, hypernatremia (odds ratio (OR) = 2.4; 95% confidence interval (CI) = 1.3-4.2), hyperkalemia (OR = 2.7; 95% CI = 1.4-5.1), and multiple electrolyte abnormalities (OR = 3.1; 95% CI = 1.8-5.3) independently predicted ICU mortality. Conclusions Electrolyte imbalances are common in critically ill medical ICU patients and are significantly associated with mortality, prolonged ICU stay, and major complications. Routine monitoring and standardized correction protocols are essential to improving outcomes.