A Prospective Observational Study in Adult Medical Intensive Care Unit Patients with Drug-Induced QTc with Correlation of Serum Potassium, Magnesium Level of Clinical Outcome.

Background: Drug-induced QTc prolongation is a significant concern in critically ill patients, increasing the risk of life-threatening arrhythmias. This prospective observational study evaluates the association between QTc prolongation, serum potassium and magnesium levels, and clinical outcomes in adult medical intensive care unit (ICU) patients.

Methodology: The study included 116 adult ICU patients prescribed QTc-prolonging drugs, excluding those with atrial fibrillation, pacemakers, or early transfers. Electrocardiograms (ECG) and serum electrolyte levels were analyzed to assess QTc prolongation and its correlation with arrhythmias, ICU stay, and mortality. The Tisdale risk score categorized patients into low, medium, and high-risk groups.

Results: QTc prolongation occurred in 29 patients, with males showing a higher incidence. Common diagnoses included sepsis, myocardial infarction, and coronary artery disease. Drugs frequently implicated were ondansetron (17.24%), fluconazole (10.34%), and amiodarone (6.89%). Among these, 11 patients were high-risk, 12 moderate-risk, and 6 low-risk. Significant changes were noted in ECG and potassium levels, but not in magnesium, chloride, or creatinine.

Conclusion: This study highlights the importance of monitoring and managing QTc-prolonging medications and associated risk factors, such as serum potassium and magnesium levels, to reduce arrhythmia risk and improve ICU outcomes.