Rapid correction of hyperkalemia is associated with reduced mortality in ED patients

Abstract

Background: Hyperkalemia (HK) is common and associated with mortality. Our purpose was to determine if the rapid correction of elevated serum potassium level (K⁺) was associated with reduced mortality in emergency department (ED) patients.

Methods: Design: We reviewed the electronic medical records (EMR) of ED patients with HK (K⁺ ≥ 5.5 mEq/L) from 10/2016-10/2017.

Setting: Large, academic ED.

Participants: Adult ED patients presenting with hyperkalemia. Main outcomes and measures: The main outcome was in-hospital mortality. We compared outcomes of patients whose K⁺ normalized (dropped below 5.5 mEq/L) with those whose K⁺ did not normalize using chi-square and multivariate analyses to determine the associations between predictor variables and outcomes.

Results: From 114,977 ED visits, 1033 patients (0.9%, 95%CI 0.85-0.95%) had HK. Their mean (SD) age was 60 (26) years and 58% were male. Of these, 884 had a second K⁺ measured within a median (IQR) of 5 (3-8) hours. Mortality and admission rates were higher in patients with HK vs. those with normal K⁺ (8.5% vs. 0.8%, P < 0.001 and 80% vs. 39%, P < 0.001, respectively). Mortality was lower in patients whose HK normalized compared with those whose K⁺ remained elevated (6.3% vs. 12.7%, P = 0.001). After adjusting for age, creatinine, comorbidities, and initial K⁺, normalization of K⁺ was associated with reduced mortality (OR 0.47, 95%CI 0.28 to 0.80).

Conclusions: Normalization of K⁺ during the ED stay in patients with HK is associated with a 50% mortality reduction. Efforts to rapidly identify and treat HK in the ED are needed.

Keywords: Emergency department; Hyperkalemia; Mortality.