BackgroundFew studies have evaluated the prevalence of severe hyperkalaemia in unselected patient populations. We identified all episodes of severe hyperkalaemia occurring in 1 year, and described patient demographics, clinical response and outcome. We also assessed junior doctor knowledge of its causes and significance.Materials and methodsA retrospective interrogation of the database of the regional biochemical laboratory identified all episodes of severe hyperkalaemia (K≥ 6.5 mmol/L) occurring in 2011. The understanding of trainee doctors of the importance, causes and treatment of severe hyperkalaemia was assessed by structured questionnaire.ResultsSevere hyperkalaemia was recorded in 433 samples (365 patients) giving a prevalence of 0.11%. Thirty-six per cent of episodes occurred in patients under the care of a nephrologist, who were significantly younger than those not under the care of a nephrologist. In the nephrology cohort, 86% occurred in patients with chronic kidney disease (CKD), the majority of which had CKD Stage 5. In the non-nephrology cohort, only 65% occurred in the context of CKD, which was equally distributed between Stages 3 and 5 CKD. In both patient groups, roughly 50% of episodes occurred in association with acute kidney injury (AKI). Acute mortality (death within 48 h of documented severe hyperkalaemia) was higher in the non-nephrology compared with the nephrology cohort. Time to repeat serum potassium was influenced by the clinical setting with shorter time to repeat for acute care compared with ward settings. Assessment of trainee doctor's knowledge suggested significant deficiencies in relation to severe hyperkalaemia.ConclusionsThe prevalence of severe hyperkalaemia was low and occurred predominantly in the context of CKD and/or AKI. The majority of episodes occurred in patients not under the care of a nephrologist. Variability in time to repeat serum potassium levels suggested deficiencies in care, and assessment of trainee doctor’s knowledge suggests the need for further educational initiatives to highlight its importance.

Endocardial fibroelastosis developed in the heart of a patient who had chronic lymphocytic leukemia. Leukemic infiltrates were found in the endocardial scar tissue, myocardium, coronary arteries, and other viscera. In view of the absence of any other known cause of endocardial fibroelastosis, it is postulated that endocardial fibroelastosis was caused by myocardial leukemic infiltration. This is the first reported case of endocardial fibroelastosis in a patient with chronic lymphocytic leukemia.

Correspondence 965 2.1 for the respective birthweights. The relative risks for the two outcomes by birthweight are similar. Data for subsequent years will be of better quality than for 1978 as the birthweight is now recorded for a greater number of infant deaths. Such data will serve to confirm or refute the association pointed out here.