Hyperkalaemia in the emergency department: Epidemiology, management and monitoring of treatment outcomes.

OBJECTIVE: To describe the epidemiology, treatment and monitoring of treatment outcomes of patients presenting to the ED with hyperkalaemia. METHODS: We undertook a retrospective observational study in a mixed adult/paediatric ED over five 3-month periods. Consecutive patients were included if they had an initial serum or blood gas potassium ≥6.0 mmol/L. Patients were excluded if their principal diagnosis was diabetic ketoacidosis, their blood sample was haemolysed or the blood gas result was inconsistent with a subsequent serum potassium. Data were extracted from electronic medical records and two senior emergency registrars independently assessed available ECGs. Moderate and severe hyperkalaemia were potassium 6.0-6.4 and ≥6.5 mmol/L, respectively. RESULTS: Overall, 392 patients were included (mean age 73.7 years, triage category 1 or 2 28.3%, admitted 91.3%). Three hundred and twenty-one (81.9%, 95% confidence interval [CI] 77.6-85.5%) patients took one or more medications that predispose to hyperkalaemia and 335 (85.5%, 95% CI 81.5-88.7%) had one or more predisposing comorbidities. Two hundred and seventy-one (69.1%, 95% CI 64.3-73.6%) patients had moderately severe and 121 (30.9%, 95% CI 26.4-35.7%) had severe hyperkalaemia. Two hundred and fifty-nine (66.1%, 95% CI 61.1-70.7%) patients were administered at least one medication in ED to lower the potassium concentration and 51 (13.0%, 95% CI 9.9-16.8%) were dialysed. One hundred and eighty-seven patients received intravenous insulin: 40 (21.4%) had documented biochemical hypoglycaemia, but 45 (24.1%) had no post-insulin blood glucose level documented. Hyperkalaemia-associated ECG changes were uncommon. CONCLUSION: Most ED patients with hyperkalaemia have identifiable clinical and medication-related risk factors. Variations in care were widespread and monitoring for iatrogenic adverse events was suboptimal.