Hyperkalaemia is often asymptomatic and is uncovered during routine laboratory testing.
Patients with severe hyperkalaemia may complain of non specific symptoms:
- muscular function
- paresthesiae
- muscle weakness
- fatigue
- cardiac function
- arrhythmias
- chest pain mimicking myocardial infarction, along with sweating, nausea, vomiting, extreme lethargy, weakness and giddiness (1,2)
The following investigations can be used for evaluation of suspected hyperkalaemia:
- repeat serum measurement of potassium to identify pseudohyperkalaemia
- other laboratory studies include:
- blood biochemistry for kidney function - serum creatinine, urea, BUN etc
- urine electrolytes and creatinine
- arterial blood gas analysis
- further investigations may be necessary to examine co-existing illnesses:
- measurement of serum glucose - to evaluate for hyperglycemia
- measurement of serum renin, aldosterone, and cortisol - to further investigate kidney and adrenal function
- consider urgent ECG in patients with
- a serum potassium >6.5 mmol/L (severe hyperkalaemia can still be present in patients without obvious ECG changes)
- symptoms of hyperkalaemia
- suspicion of rapid-onset hyperkalaemia
- underlying kidney disease, heart disease, or cirrhosis who have a new case of hyperkalaemia (1,2)
Note that emergency treatment is necessary if the serum potassium rises ≥6.5 mmol/L or if there are ECG changes associated with hyperkalaemia (3).
Reference:
(1) Kim MJ, Valerio C, Knobloch GK. Potassium Disorders: Hypokalemia and Hyperkalemia. Am Fam Physician. 2023 Jan;107(1):59-70.
(2) UK Kidney Association. Clinical Practice Guidelines - Management of Hyperkalaemia in Adults. October 2023.
(3) Lott C et. al. European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances. Resuscitation. 2021 Apr;161:152-219. doi: 10.1016/j.resuscitation.2021.02.011.