High, Low Potassium Levels Up In-Hospital Mortality

ORLANDO, Fla.—Serum potassium levels below 4.0 and above 5.0 mEq/L at hospital admission are associated with an increased risk of in-hospital mortality, according to a study presented at the National Kidney Foundation’s 2017 Spring Clinical Meetings.

A serum potassium level of 4.0–4.5 mEq/L at admission is associated with the lowest incidence of in-hospital mortality, researchers at Mayo Clinic in Rochester, Minnesota, reported.

“Hypokalemia and hyperkalemia are common electrolyte disorders in hospitalized patients,” lead investigator Wisit Cheungpasitporn, MD, told Renal & Urology News. “The effect of serum potassium levels at hospital admission on risk of in-hospital mortality has not been examined. The findings from our study may aid risk stratification and decision making in hospitalized patients with various admission potassium levels.”

The single-center retrospective study included 73,983 hospitalized adult patients who had serum potassium values available from 2011 to 2013. After adjusting for potential confounders, including age, sex, race, glomerular filtration rate, and comorbidities, serum potassium levels (mEq/L) below 3.0, 3.0–3.5, 3.5–4.0, 5.0–5.5, and 5.5 or higher were associated with 3.3, 2.4, 1.4, 1.9, and 3.6 times increased odds of in-hospital, respectively, compared with a reference value of 4.0–4.5 mEq/L.

Among hospitalized patients with cardiovascular disease, serum potassium levels below 3.0 were associated with the highest in-hospital mortality. Compared with the reference value, a level below 3.0 had 5.5-fold increased odds of in-hospital mortality. Among patients with chronic kidney disease, those with potassium levels of 5.5 or higher had a nearly 3-fold increased odds of in-hospital mortality.

See more coverage from the National Kidney Foundation Spring Clinical meeting.

Reference

Cheungpasitporn W, Thongprayoon C, Kittanamongkolchai W, et al. Admission serum potassium and mortality in hospital patients. Poster presented at the National Kidney Foundation’s 2017 Spring Clinical Meetings. Poster 258.