Emergency department referral and short-term death after outpatient hyperkalemia: a population-based study
In brief
Emergency department visit within 24 hours cuts 1-day death risk by 60% after severe outpatient hyperkalemia
In a province-wide cohort of 57,600 adults with potassium > 6.2 mmol/L, patients who were seen in the emergency department within a day had a one-day mortality of 0.4% versus 1.0% for those managed outpatient, and the benefit persisted to seven days. The greatest survival gain was seen in those with potassium > 6.6 mmol/L or eGFR < 30 mL/min, highlighting the need for rapid referral pathways.
- Journal
- CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne (Q1)
- Published
- 7 September 2026
- Study design
- Retrospective cohort
- Evidence level
- Level 3, Low (CEBM 3b)
- Authors
- Michael Chiu, Danielle M Nash, Graham Smith, Mohamed Abou El Hassan, Louise Moist, Amit X Garg, et al.
- PMID
- 42710931
- DOI
- 10.1503/cmaj.252008
Why clinicians should know about it
- Picked for Emergency Medicine (paper of the day, 9 September 2026): ED referral reduces short-term mortality in severe hyperkalemia
Abstract
BACKGROUND: Hyperkalemia can be deadly, yet clinical decision-making for outpatient management is unclear. We sought to determine whether an emergency department encounter within 24 hours of a severe outpatient hyperkalemia result was associated with lower rates of immediate and short-term all-cause death. METHODS: We conducted a retrospective population-based cohort study in Ontario, Canada, involving adults (age ≥18 yr) with an outpatient potassium result greater than 6.2 mmol/L from Jan. 1, 2007, to Dec. 24, 2021. Patients who presented to the emergency department were propensity matched (1:1) to patients who did not. We estimated risk ratios and risk differences for all-cause death within 1, 3, and 7 days after the encounter. We performed subgroup analyses based on kidney function, sex, diabetes, renin-angiotensin-aldosterone inhibitor use, potassium level, and ordering physician specialty. RESULTS: A total of 57 607 individuals had an outpatient potassium result greater than 6.2 mmol/L. Among these individuals, 7469 emergency department encounters occurred. After matching, 6557 patients had an emergency department encounter and 6557 did not. Within 7 days, a total of 209 deaths (1.6%) occurred. The risk of death was significantly lower among those with an emergency department encounter at 1 day (risk ratio [RR] 0.39, 95% confidence interval [CI] 0.24 to 0.65), 3 days (RR 0.47, 95% CI 0.32 to 0.67), and 7 days (RR 0.69, 95% CI 0.52 to 0.90). Subgroup analysis showed the greatest mortality reduction among patients with higher potassium levels (>6.6 mmol/L) and impaired kidney function (estimated glomerular filtration rate <30 mL/min/1.73 m2). INTERPRETATION: Presentation to the emergency department within 24 hours of a severe outpatient hyperkalemia result is associated with lower rates of immediate and short-term death. These findings support urgent emergency department referrals and underscore the need for standardized reporting and management guidelines.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.