All-cause mortality associated with hyperkalaemia in hospitalised adult patients: a scoping review

Abstract

Introduction: Although the association between hyperkalaemia and all-cause mortality has been described, the evidence for it is fragmented and underrepresents populations from low- and middle-income countries. We conducted a scoping review to map existing research on hyperkalaemia-associated mortality in hospitalised adults and identify key gaps in the literature.
Materials and methods: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis-Scoping Reviews. Studies from January 2001 to January 2025 were eligible for inclusion. The following bibliographic databases were searched: Medline (PubMed), CINHAL (EBSCOhost), and Web of Science (Clarivate). The final protocol was registered with the Open Science Framework.
Results: Twenty-two studies were included, encompassing 777,020 patients, of whom 78,685 (10.1%) developed hyperkalaemia. The overall in-hospital mortality among these hyperkalaemia patients was 22.8% (95% CI 22.5–23.1%). Frequent comorbidities were lung disease (67.2%), liver disease (53.1%), congestive cardiac failure (42.9%) and acute kidney injury (AKI) (30.8%). Acute kidney injury was associated with the highest mortality rate (41%). Serum potassium concentration ([K+]) was a consistent independent predictor of death in 9 of 11 multivariate analyses; however, the correlation between [K+] and mortality was weak (r = 0.248, P = 0.489). Geographic representation was skewed, with only three studies conducted in Africa.
Conclusion: This scoping review mapped current evidence on hyperkalaemia-associated all-cause mortality in hospitalised adults, and was relatively high, especially with concurrent AKI. We found that [K+], acute kidney injury, and age were the most common independent predictors of death. Future research should standardise definitions of hyperkalaemia and expand geographic representation, particularly in Africa.