A retrospective study of emergency department potassium disturbances: severity, treatment, and outcomes

Abstract

Objective Disturbances in potassium (K) levels are relatively common and may be associated with significant morbidity and mortality; however, treatments vary. Our purpose was to determine the incidence, treatments, and outcomes associated with hyperkalemia and hypokalemia in emergency department (ED) patients. Methods We performed a structured, retrospective review of electronic medical records of consecutive adult ED patients with K measured while in the ED. Demographic, clinical, and laboratory data as well as treatments, disposition, and in-hospital complications were collected. Uni-variate and multivariate analyses, presented as adjusted odds ratios, were used to compare outcomes by K levels. Results Of 100,260 visits in 2014, an ED K level was ordered in 48,827 (49%). A total of 1,738 patients (3.6%) were excluded because of sample hemolysis. The K was low (<3.5 mEq/L) in 5.5%, normal (3.5 to 5.0 mEq/L) in 90.9%, and elevated (>5.0 mEq/L) in 3.6% of patients. Patients with hyperkalemia were older (64 vs. 49 years, P<0.001) and more likely male (58% vs. 40%, P<0.001). Treatment for hyperkalemia varied greatly. After adjusting for confounders, both hyperkalemia and hypokalemia were associated with inpatient hospitalization and death. At least one medication was used to manage hyperkalemia in 11.5% of patients with a K of 5.1 to 5.4 mEq/L, 36.4% of those with a K 5.5 to 6 mEq/L and 77.0% of the cohort with K >6 mEq/L. Conclusion Hyperkalemia or hypokalemia occur in 1 of 11 ED patients and are associated with inpatient admission and mortality. Treatment of hyperkalemia varies greatly suggesting the need for evidence-based treatment guidelines.