Replacing Potassium in the Emergency Department May Not Decrease the Hospital Mortality in Mild Hypokalemia: A Propensity Score Matching Analysis

Background: Hypokalemia is associated with considerable morbidity and mortality, highlighting the timely correction of potassium levels as a critical medical consideration. However, the management of mild hypokalemia remains a subject of ongoing debate. This study explores the relationship between potassium replacement in the emergency department (ED) and hospital mortality in patients with mild hypokalemia. Methods: This retrospective cohort study was conducted at a tertiary care hospital, including patients who presented to the ED with mild hypokalemia, defined as potassium levels between 3.0 and 3.4 mmol/L, between 2020 and 2021. Patients diagnosed with acute coronary syndrome, diabetic ketoacidosis, hyperglycemic hyperosmolar state, and major cardiac arrhythmias were excluded. The patient cohort was then divided into two groups, based on whether they received potassium replacement in the ED. A propensity score analysis was employed to account for potential pretreatment confounding factors, including age, gender, time on ED arrival, insurance, comorbidities, serum potassium and creatinine levels, and ED length of stay. Subsequently, a multivariable logistic regression analysis, incorporating hospital length of stay and acute comorbidities, was performed post-matching to further adjust for predictive factors. The primary outcome was all-cause hospital mortality. Results: This study included a total of 1931 patients, of which 724 were matched for analysis (362 with potassium replacement and 362 without). The average age was 53.9 years, and most were male (58.5%). After adjusting for confounding factors using propensity score analysis, there was no significant difference in hospital mortality between the potassium replacement and control groups (adjusted odds ratio 0.81, 95% CI 0.36-1.79, p = 0.60). Conclusions: This study's findings indicate that replacing potassium in the ED may not lower the risk of hospital mortality in patients with mild hypokalemia. Consequently, the customary practice of potassium replacement in hospitalized patients may lack justification, and deferring the replacement until after patients leave the ED could be considered.