Clinical investigation of a point-of-care blood ammonia analyzer

Goggs, R A; Serrano, S; Szladovits, B; Keir, I; Ong, R; Hughes, D

Abstract

Background: Hyperammonemia has frequently been implicated in the pathogenesis of hepatic encephalopathy. Blood ammonia determination requires minimal delay between sampling and analysis for accurate results. Objectives: The aim of this study was to investigate the PocketChem BA, a new point-of-care (POC) blood ammonia analyzer for clinical use by determining machine precision, linearity, repeatability, and accuracy. Methods: Coefficients of variation were determined by repeated measurement of 2 control solutions. Linearity was investigated by testing serial dilutions of a stock solution. For accuracy, samples from clinical cases were used to compare the results on the PocketChem BA with those obtained using an enzymatic reference method for canine plasma. Canine and feline patients were consecutively enrolled if blood ammonia was assayed and samples could be analyzed shortly after collection. Classification of results (as normal or high, using 100 mu mol/L as a cutoff value), Bland-Altman and Deming regression plots, and intraclass correlation coefficients were used to compare the methods. Stability of samples and test strips also was assessed over time. Results: Coefficients of variation were 10.6% and 4.8% for low and high controls, respectively. Concentrations of ammonia in diluted stock solutions correlated positively with mean measured concentrations (Pearson coefficient 0.988, P

Citation

Goggs, R. A., Serrano, S., Szladovits, B., Keir, I., Ong, R., & Hughes, D. Clinical investigation of a point-of-care blood ammonia analyzer. Veterinary Clinical Pathology, 37(2), 198-206. https://doi.org/10.1111/j.1939-165X.2008.00024.x

• Journal Article Type: Article
• Deposit Date: Nov 11, 2014
• Journal: Veterinary Clinical Pathology
• Print ISSN: 0275-6382
• Electronic ISSN: 1939-165X
• Publisher: Wiley
• Volume: 37
• Issue: 2
• Pages: 198-206
• DOI: https://doi.org/10.1111/j.1939-165X.2008.00024.x
• Public URL: https://rvc-repository.worktribe.com/output/1429472