Reliability of capillary blood potassium measurements in children with acute gastroenteritis

• Published in: Archives of disease in childhood Vol. 103; no. 11; pp. 1091 - 1093
• Main Authors: Nowak, Jan Krzysztof, Wielińska, Hanna, Dąbrowski, Michał, Szydłowska, Paula, Szczepanik, Mariusz, Krzyżanowska, Patrycja, Duclaux-Loras, Rémi, Walkowiak, Jarosław
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01-11-2018
• Subjects: Accuracy; Blood; Body Composition; Children; Comorbidity; Correlation; Gastroenteritis; Gastroenterology; Instrumentation; Kopernik, Mikolaj (Nicolaus Copernicus) (1473-1543); Laboratories; Patients; Pediatrics; Potassium; Respiratory tract; Sampling; Poland; measurement; gastroenterology; statistics
• ISSN: 0003-9888; 1468-2044
• DOI: 10.1136/archdischild-2017-314561

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 assessed using Stat Profile (Nova Biomedical; until 2006), IL1304 (Instrumentation Laboratory; until 2009), AVL OMNI 3 (Roche Diagnostics; until May 2010), ABL835 Flex (Radiometer Medical; since January 2008) and RAPIDLab 1265 (Siemens Healthcare; since June 2010). Means±SD are presented Parameter All patients Subgroup Sample size 247 90 Age (years) 2.7±2.6 2.9±2.7 Body mass on admission (kg) 15±8 16±8 Sex 131 (53.0%) male 116 (47.0%) female 52 (57.8%) male 38 (42.2%) female Capillary sampling time, from admission (min) 6±44 13±37 Venous sampling time, from admission (min) 136±58 98±43 Time from capillary to venous results (min) 131±46 85±21 pH 7.38±0.05 7.38±0.04 Capillary K+ (mmol/L) 4.46±0.76 4.34±0.78 Venous K+ (mmol/L) 4.19±0.47 4.18±0.45 Hypokalaemia/hyperkalaemia (venous) 1.2%/2.4% 4.4%/1.1% Comorbidities 33.7% 31.1%  Respiratory tract, % of cases with comorbidities 53 64 Symptom frequency (n=241)  Vomiting 82% 90%  Diarrhoea 68% 64%  Fever 35% 31%  Lethargy 26% 25% Symptom duration before admission, days (n=184/247) 2.0±1.3 1.9±1.5 Rotaviral infection (n=191 tested) 53.4% 53.3% Adenoviral infection (n=191 tested) 0.5% 0.1% This is the first study to document insufficient accuracy of potassium measurement in capillary blood in a large paediatric cohort. [...]measurements of potassium via capillary blood are unreliable in children with AGE.