Main aim of treatment is to increase potassium to safe levels in order to prevent life-threatening cardiac conduction disturbances and neuromuscular dysfunctions (1).
- severity of symptoms, rather than the potassium level can be used as a guide to identify the urgency of treatment
- further replenishment and management of the underlying disorder can be undertaken secondarily
- identifying the underlying cause of hypokalaemia is important since the condition is rarely an isolated event (2)
- maintaining a serum potassium level of at least 4mmol/l should be the target in patients with a history of congestive heart failure and myocardial infarction
It is important to identify patients at risk of hypokalaemia or from its effects since any level of hypokalaemia may have serious affects
- risk factors include: elderly patients, arrythmogenic heart disease (3)
Management of mild hypokalaemia (3.1 < serum K < 3.5):
- patients may be asymptomatic
- in otherwise untreated low‐risk individuals, mild hypokalaemia may be of limited clinical significance
- repeat test adding creatinine, sodium and bicarbonate
- treatment of the underlying disorder may alleviate the hypokalaemia
- e.g - if diuretic is the cause, stopping or reducing the dosage may be sufficient
- compare with previous results since the condition may be transient
- if indicated, ambulatory replacement may be carried out
Management of moderate hypokalaemia (serum K > 2.5 < 3.0 mmol/l):
- compare with previous results, if inconsistent, repeat test on same/next day basis
- assess for clinical features and risk factors
- perform an ECG
- if patient is at risk or with symptoms, seek urgent specialist advice
- if ambulatory potassium replacement is considered, weigh risks/benefits on individual case basis
Management of severe hypokalaemia (serum K <2.6 mmol/l)
- compare with previous results, if inconsistent, repeat test urgently
- seek urgent specialist advice
- perform ECG
- in case of critical ECG, consider first aid
Oral ambulatory treatment of hypokalaemia for mild and low risk moderate hypokalaemia:
- treatment of underlying cause
- dietary supplementation
- potassium supplementation (40-120 mmol/day depending on severity and urgency)
- regular monitoring of potassium levels (according to the severity)
- aim to achieve a potassium level of 4.5 mmol/l or more with replacement in higher-risk patients
Intravenous potassium supplementation is normally carried out in hospitals as intravenous treatment is hazardous and impractical in most ambulatory situations.
- due to its complications, IV potassium replacement is usually reserved for patients with severe hypokalaemia, hypokalaemic ECG changes, or physical signs or symptoms of hypokalaemia, or for those unable to tolerate the oral form.
- standard administration is 20 to 40 mmol of potassium in 1 L of normal saline
- replacement should not exceed 20 mmol/h and if the rate exceeds 10 mmol per hour, continuous cardiac monitoring is indicated (1,2)
Treatment of hypokalaemic periodic paralysis is with carbonic anhydrase inhibitor and potassium supplements.
Reference:
- (1) Kim MJ, Valerio C, Knobloch GK. Potassium Disorders: Hypokalemia and Hyperkalemia. Am Fam Physician. 2023 Jan;107(1):59-70.
- (2) Kardalas E, Paschou SA, Anagnostis P, Muscogiuri G, Siasos G, Vryonidou A. Hypokalemia: a clinical update. Endocr Connect. 2018 Apr;7(4):R135-R146. doi: 10.1530/EC-18-0109.
- (3) Smellie WSA, Shaw N, Bowlees R, Taylor A, Howell‐Jones R, McNulty CAM. Best practice in primary care pathology: review 9. Journal of Clinical Pathology. 2007;60(9):966-974.