Hyperkalemia, Disease Severity, Mortality Risk Among ER Patients

In a study published in BMC Emergency Medicine, Jian Sun and others examined the influence of hyperkalemia on disease severity and mortality risk among patients admitted to the emergency room (ER). Their retrospective, observational study utilized data from the Chinese Emergency Triage Assessment and Treatment database and included 12,799 ER patients.

The researchers categorized patients based on serum potassium levels and used multifactorial logistic regression and receiver operating characteristic analysis to evaluate relationships between serum potassium levels, severity of illness, and risk of mortality. They also assessed the effectiveness of various treatments at lowering potassium levels.

Hyperkalemia among ER patients was not uncommon; 20.10% (n=2577) were hypokalemic and 2.98% (n=381) were hyperkalemic. Hyperkalemic patients most often visited the ER for altered consciousness (23.88%; n=91), cardiovascular symptoms (22.31%; n=85), and gastrointestinal symptoms (20.47%; n=78).

The most prescribed hyperkalemia treatments were diuretics (57.32%; n=188), intravenous sodium bicarbonate (50.91%; n=167), intravenous calcium (37.20%; n=122), insulin in combination with high glucose (27.74%; n=91), and continuous renal replacement therapy (CRRT; 19.82%; n=65). CRRT was the most effective for reducing potassium levels. Diuretics proved largely ineffective, and sodium bicarbonate, calcium, and high-glucose insulin had no significant effect on the rate of potassium decline.

Hyperkalemia was found to be an independent factor associated with mortality among ER patients and was a strong predictor of death (area under the curve, 0.89). Mortality risk seemed to positively correlate with higher potassium levels, peaking when blood potassium levels ranged between 6.5 and 7.0. This finding may be due, in part, to delayed admission to an intensive care unit and a lower rate of CRRT, and socioeconomic factors may be at play.

The study’s limitations include the small sample size of patients with hyperkalemia, the inability to collect extensive data, and the fact that data came from just two regional medical centers of large tertiary hospitals, meaning results may not be representative of other practices.

In sum, the authors noted that hyperkalemia is common among patients in ERs and is associated with higher mortality and intensive care unit admission. CRRT is the most effective treatment, and diuretics should be used cautiously. “Fac­tors [that] influence health-seeking [behaviors] are not well understood in this field, nor are the factors [that] influence clinical judgments in ERs; these are two areas [that] require further investigation to improve outcomes,” they wrote.

Source: BMC Emergency Medicine