RESUMEN
Hypokalaemia is a common electrolyte disorder affecting hospitalised patients. It is associated with adverse outcomes including increased mortality. Inpatients with hypokalaemia need a different approach to workup and management as the aetiologies and progression of the hypokalaemia are distinct to outpatients. Potassium homeostasis is predominantly maintained by renal potassium handling. The clinical manifestations of hypokalaemia depend on the severity of hypokalaemia, however, most of the findings are non-specific. The approach to management is guided by the severity of the hypokalaemia and the underlying aetiology. Oral potassium replacement can be used in many cases of mild hypokalaemia. Intravenous replacement of potassium is necessary for many inpatients. Close monitoring is essential to ensure adequacy and to prevent adverse outcomes. An interdisciplinary approach with critical care input is needed in severe cases, and in patients where routine intravenous replacement may not be feasible (e.g., patients with heart failure). In addition to replacement, the cornerstone of management is a comprehensive review of the patient to identify the underlying cause of the hypokalaemia and the factors sustaining it. In patients in whom the cause is not apparent, or the potassium does not improve as anticipated, a referral to nephrology or endocrinology should be considered. This paper reviews the assessment of hypokalaemia in a hospital setting. It is aimed at early career doctors on the wards to help carry out a thorough evaluation. It also provides a useful framework for management.