Electrolyte disorders in the critically ill

Electrolyte disorders are ubiquitous in the critically ill patient. Abnormalities may provide clues to the diagnosis, severity and even prognosis of illnesses. Abnormal serum electrolytes can be a marker of total body electrolyte deficit or excess, or movement between compartments. Despite the morbidity and mortality associated with electrolyte disorders in critically ill patients, the evidence to guide management is limited. This article provides a guide to the aetiology, clinical features and management of major electrolyte disorders in the patients in the intensive care unit.