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HomeHaematologyElectrolyte disorder a major driver of SA hospital deaths – Stellenbosch study

Electrolyte disorder a major driver of SA hospital deaths – Stellenbosch study

Hyperkalaemia, an electrolyte disorder caused by too much potassium in the blood and which leads to heart attacks, is quite prevalent among those with chronic conditions, and one of the major drivers of South African hospital deaths.

According to a recent Stellenbosch University study, the condition, which can come on suddenly, was responsible for about 30% of deaths among patients with long-term conditions such as high blood pressure, diabetes, HIV and kidney failure, say researchers, who added that people with kidney failure are more likely to die from it than any other high-risk group.

The Sunday Times Daily reports that despite little data on the epidemiology of this condition in Africa, experts hope their comprehensive research at Tygerberg Hospital in the Western Cape, will provide better insight into its treatment and mortality risk factors.

Their research, involving about 2,000 patients between January and December 2019, was the largest that reported the epidemiology of hyperkalaemia in Africa. Researchers said in hospitalised patients it may cause life-threatening cardiac arrhythmias, resulting in cardiac arrest if not optimally treated.

Lead researcher Dr Yazied Chothia, a Stellenbosch University senior lecturer and nephrologist, and colleagues, found the incidence rate of hyperkalaemia to be 3.7 cases per 100 patient years. Nearly a third of patients died and acute kidney injury was a major predictor of hospital deaths.

About 14% of patients with hyperkalaemia were HIV-positive, but there was no difference in hospital death compared with the HIV-negative.

Most patients who died of hyperkalaemia arrived at hospital late and died within a day of diagnosis.

Researchers also found that patients on renin-angiotensin-aldosterone system inhibitors (RAASi) before admission were less likely to die in hospital compared with patients who were not. These prescription drugs are mostly used for hypertensive patients, those with heart disease and chronic kidney diseases. Even though they often slow down the progression of these chronic conditions, drugs in this class are frequently discontinued as a result of hyperkalaemia.

Chothia said the increase in mortality within the first 24 hours of hyperkalaemia diagnosis was similar to existing research. Despite the risk posed by RAASi use in the face of hyperkalaemia, a mortality benefit was observed. “This may highlight the importance of continuing RAASi therapy.”

Study details

How common is hyperkalaemia? A systematic review and meta-analysis of the prevalence and incidence of hyperkalaemia reported in observational studies

Toby Humphrey, Mogamat Razeen Davids, Mogamat-Yazied Chothia, Roberto Pecoits-Filho, Carol Pollock, Glen James

Published in Clinical Kidney Journal in Volume 15 in April 2022.


The prevalence and incidence of hyperkalaemia, a potassium abnormality that can potentially have life-threatening consequences, are unclear.

The objective was to provide the most comprehensive overview of the epidemiology of hyperkalaemia to date within the general population, across different continents, in different healthcare settings and within pre-specified subgroups. Embase and MEDLINE were searched from database inception to 2 February 2021 using the Ovid SP platform. Relevant congress proceedings from 2018 to 2020 were also reviewed for inclusion. There was no language constraint applied. Observational studies from any time period and language reporting prevalence or incidence of hyperkalaemia within both adult and paediatric populations. Four investigators independently screened abstracts and assessed study quality of those meeting the pre-determined inclusion/exclusion criteria. Data extraction was conducted by the lead author with oversight from the senior author and data were pooled using a random-effects model. The measures assessed were the prevalence and incidence of hyperkalaemia. Prevalence was reported as a percentage, whilst incidence was reported as the rate per 100 person years.

In total, 542 articles were included from an initial search of 14 112 articles. Across all adult studies, we report a prevalence of hyperkalaemia (by any definition/threshold) of 6.3% [95% confidence interval (CI): 5.8–6.8%], with an incidence of hyperkalaemia in the adult population of 2.8 (2.3–3.3) cases per 100 person years. Prevalence within the general population was 1.3% (1.0–1.8%), whilst incidence was 0.4 (0.2–0.8) cases per 100 person years. There was a variation by sex with a prevalence of 6.3% (4.9–8.0%) in males and 5.1% (4.0–6.6%) in females. Prevalence also varied according to the definition/threshold of hyperkalaemia used: >5 mmol/L—8.0% (7.2–8.9), ≥5.5 mmol/L—5.9% (3.5–10.0) and ≥6.0 mmol/L—1.0% (0.8–1.4); hyperkalaemia (by any definition/threshold) was highest amongst patients with end-stage kidney disease (21.5%; 18.3–25.3), kidney transplant patients (21.8%; 16.1–29.5) and patients with acute kidney injury (24.3%; 19.3–30.7).

This novel review provides a comprehensive and valuable resource on the prevalence and incidence of hyperkalaemia to better inform clinicians, healthcare providers and health policy makers on the burden of hyperkalaemia across different healthcare settings, patient populations and continents.


Sunday Times Daily article – Lesser-known electrolyte disorder a major driver of hospital deaths in SA (Restricted access)


Clinical Kidney Journal article – How common is hyperkalaemia? A systematic review and meta-analysis of the prevalence and incidence of hyperkalaemia reported in observational studies (Open access)


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