Abstract
IntroductionThe electrocardiogram (ECG) is often used to identify which hyperkalemic patients are at risk for adverse events. However, there is a paucity of evidence to support this practice. This study analyzes the association between specific hyperkalemic ECG abnormalities and the development of short-term adverse events in patients with severe hyperkalemia.MethodsWe collected records of all adult patients with potassium (K+) ≥6.5 mEq/L in the hospital laboratory database from August 15, 2010, through January 30, 2015. A chart review identified patient demographics, concurrent laboratory values, ECG within one hour of K+ measurement, treatments and occurrence of adverse events within six hours of ECG. We defined adverse events as symptomatic bradycardia, ventricular tachycardia, ventricular fibrillation, cardiopulmonary resuscitation (CPR) and/or death. Two emergency physicians blinded to study objective independently examined each ECG for rate, rhythm, peaked T wave, PR interval duration and QRS complex duration. Relative risk was calculated to determine the association between specific hyperkalemic ECG abnormalities and short-term adverse events.ResultsWe included a total of 188 patients with severe hyperkalemia in the final study group. Adverse events occurred within six hours in 28 patients (15%): symptomatic bradycardia (n=22), death (n=4), ventricular tachycardia (n=2) and CPR (n=2). All adverse events occurred prior to treatment with calcium and all but one occurred prior to K+-lowering intervention. All patients who had a short-term adverse event had a preceding ECG that demonstrated at least one hyperkalemic abnormality (100%, 95% confidence interval [CI] [85.7–100%]). An increased likelihood of short-term adverse event was found for hyperkalemic patients whose ECG demonstrated QRS prolongation (relative risk [RR] 4.74, 95% CI [2.01–11.15]), bradycardia (HR<50) (RR 12.29, 95%CI [6.69–22.57]), and/or junctional rhythm (RR 7.46, 95%CI 5.28–11.13). There was no statistically significant correlation between peaked T waves and short-term adverse events (RR 0.77, 95% CI [0.35–1.70]).ConclusionOur findings support the use of the ECG to risk stratify patients with severe hyperkalemia for short-term adverse events.
Highlights
The electrocardiogram (ECG) is often used to identify which hyperkalemic patients are at risk for adverse events
Adverse events occurred within six hours in 28 patients (15%): symptomatic bradycardia (n=22), death (n=4), ventricular tachycardia (n=2) and cardiopulmonary resuscitation (CPR) (n=2)
An increased likelihood of short-term adverse event was found for hyperkalemic patients whose ECG demonstrated QRS prolongation, bradycardia (HR
Summary
The electrocardiogram (ECG) is often used to identify which hyperkalemic patients are at risk for adverse events. Cases of patients with extreme hyperkalemia (10.1-10.3 mEq/L) and normal ECGs have been reported.[9,10] dysrhythmia and cardiac arrest have been reported in hyperkalemic patients without preceding peaked T waves.[11] The role of the ECG in the management of hyperkalemia has been increasingly called into question.[2,7,11,12,13,14] Leading FOAMed (free online open-access medical education) educators have deemphasized the role of ECG in management decisions, warning that patients with relatively normal ECGs may still experience sudden hyperkalemic cardiac arrest.[12,14] A recently published guideline for the management of severe hyperkalemia called for further research to both characterize the actual risk of cardiac instability in hyperkalemic patients without ECG abnormalities and to identify which hyperkalemic ECG changes are the greatest predictors of outcome.[15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
