Assessment of liver function tests on Piccolo Xpress point of care chemistry analyzer in a pediatric hospital

Objectives: Point of care testing (POCT) contributes to diagnosis and monitoring with fast testing time and easily performed assays. We evaluated the Abaxis Piccolo Xpress point of care chemistry analyzer using the Liver Panel Plus discs for our pediatric patient population at Texas Children's Hospital. Design and methods: Analytical performance was evaluated for precision and linearity using quality control materials and commercially available verification samples. Comparison studies were performed between Piccolo Xpress analyzer and Vitros 5600 analyzer using patient samples. Interference studies were carried out using nine different patient pool sera. Lipemia interference was removed using LipoClear for severely lipemic sample pools. Results: Precision of all tests was excellent (CVs<5% for all measured analytes except TBIL). All assays were linear and accurate within the allowable total error. Comparison studies showed that three analytes (amylase, GGT and TBIL) had statistically significant bias. Interference study results did not exceed the total allowable error for hemoglobin (<150 mg/dL), bilirubin (<15 mg/dL) and lipemia (<400 mg/dL except ALT, GGT and TP). LipoClear treatment removed lipemia interference for all analytes except total protein. Conclusions: The Piccolo Xpress chemistry analyzer showed an acceptable analytical performance for precision, linearity and interference from common substances. Increased bias for three analytes in comparison studies could be due to different methodologies. Keywords: Point of care testing, Analytical performance, Liver function tests, Precision, Method comparison, Interferenc