Record linkage study of hypokalaemia in hospitalized patients.

Retrospective analysis of biochemical data from 58,167 hospital inpatients revealed that 21% developed hypokalaemia during hospitalization-in 5.2% the serum potassium was less than 3.0 mmol/l. Subsequent evaluation showed a positive correlation between hypokalaemia and both female sex and hospital mortality. Patients with leukaemia and lymphoid tumours, especially when receiving antibiotic or cytotoxic therapy, and patients with gastro-intestinal malignancy were amongst those most frequently experiencing hypokalaemia. There was no significant association with cardiovascular disease. Drug and intravenous fluid administration accounted for the hypokalaemia in 56% of patients. While drug-related hypokalaemia was most commonly seen with diuretics, it was also apparent following use of steroids, insulin and haematinics.