Reliability of capillary blood potassium measurements in children with acute gastroenteritis

Potassium concentration in children is commonly assessed via capillary blood. Although the risk of false hyperkalaemia due to cell lysis is widely acknowledged, the quantitative data regarding the accuracy of this measurement are lacking.1–3 The aim of our study was to compare potassium concentration in the capillary blood, taken in the emergency room, with that of the serum potassium once intravenous access was obtained on admission to the ward. Health records (2006–2015) of patients discharged from Poznan University of Medical Sciences children’s hospital with the main diagnosis of acute gastroenteritis (AGE; n=1080; International Classification of Diseases, 10th Revision: A09, A08.0, A08.2) were screened for the following inclusion criteria: potassium and sodium concentrations measured in the capillary blood before admission to the ward,1 in the serum on admission to the ward,2 and a difference in time of less than 4 hours between the results of capillary and venous blood analyses.3 Capillary blood potassium was …