withdrawn

There are limited data regarding the burden of hyperkalaemia in patients attending emergency departments (ED) or who are hospitalised (excluding those already receiving dialysis). Renin-angiotensin-aldosterone system inhibitors (RAASi) are of prognostic benefit in patients with heart failure with reduced ejection fraction (HFrEF) and post myocardial infarction (MI) left ventricular systolic dysfunction (LVSD) and as such should be continued wherever possible for these indications. These drugs may contribute to elevation in serum potassium and hyperkalaemia may lead to a reduction in dose or complete withdrawal of RAASi. Yet it remains unknown how common this happens in standard clinical practice. Inappropriate discontinuation of RAASi in such patients may lead to adverse clinical outcomes. If patients have hyperkalaemia that limits the use of RAASi, they may be candidates for new potassium binders that could facilitate their continued use.

Research questions:

In an adult population of patients who are hospitalised or attending the emergency department (and not receiving dialysis) with hyperkalaemia:

1. How does hyperkalaemia impact on RAASi therapy and does this vary according to the clinical indication for the drug(s)?
2. What are the demographics, co-morbidities and drug history for patients presenting with hyperkalaemia?
3. What is the frequency of subsequent hospitalisations and mortality rate in a cohort of patients presenting with hyperkalaemia at 12 months?

Inclusion Criteria:

1. Patients in ED or inpatients with at least 1 blood test with a potassium level of ≥5.5 mmol/l
2. Receiving RAASi.
3. Aged 18 and above.
4. Able to provide informed consent or consent provided by consultee in those unable to consent for themselves.

Exclusion Criteria:

1. Patients already receiving dialysis prior to the episode of hyperkalaemia.
2. For patients considered for postal consent: known cognitive impairment, learning difficulties or brain injury or those who had transient cognitive impairment, delirium or required urgent deprivation of liberty form completion during inpatient stay or in the previous 12 months prior to hyperkalaemia episode.

Inpatients or ED attenders receiving RAASi and with an episode of hyperkalaemia (potassium ≥5.5 mmol/l)