Performance specifications of common chemistry analytes on the AU series of chemistry analyzers for miscellaneous body fluids

摘要

Background: Body fluids are frequently submitted to the clinical laboratory. Standard chemistry analyzers are generally not FDA approved for body fluid analysis and regulatory authorities require individual laboratories to validate their performance characteristics. Methods: Precision, linearity, accuracy, and sample stability were assessed for 10 different chemistry analytes using ascites, pleural, peritoneal dialysate, and synovial fluids on the Beckman Coulter (BC) AU5431. The effect of altered protein concentration and pH was investigated. Chemistry results from the AU5431 were compared with results from the BC AU5832 and the BC AU680. Additionally, 22 paired serum/pleural fluids were evaluated for their biochemical ability to distinguish a transudate from an exudate. Results: Precision for each assay and body fluid type had a CV < 14.5%. Recovery for the various analytes in all fluid types was 94.9-112%. CAP survey samples were within one SDI of the peer group. Sample pH, but not protein concentration, affected chemistry results. Inter-instrument comparison of results using the AU5431, AU5800, and AU680 was excellent. A combinatorial approach for discriminating between transudates and exudates had a sensitivity and specificity of 94% and 50%, respectively. Conclusions: Body fluid samples with pH values within the acceptable range can be analyzed on the BC AU instruments.