Multilevel qualification of a large set of blood gas analyzers: Which performance goals?

Blood gas analyzers are frequently installed as point of care devices and thus allow rapid decision making. Few data are available regarding analytical performance of large sets of BGA. We aimed at evaluating 22 ABL 90 Flex Plus analyzers intended to be deployed. The evaluation was performed at the device level and at the entire set level to characterize the quality of measurements but also to ensure consistency across the devices deployed in the hospital.

Imprecision and total error were assessed for pH, pCO2, pO2, sodium, potassium, ionized calcium, glucose, lactate and oximetry parameters. Imprecision at the hospital level including between device variability was also evaluated. One of the two analyzers used in the central laboratory was correlated with a GEM Premier 4000 and a Cobas b221 analyzers. Thereafter, we tested sequentially the 20 instruments intended to be deployed in care service in comparison with the reference device.

Heterogeneity of analytical performance across the different analyzers was low, allowing to consider the whole set as a unique analyzer. The total error was in line with performance goals. Analytical performance of the analyzers was found suitable for use in clinical practice.

Our study is an example of the qualification of a set of point and underscores 1)The need for a unified qualification scheme when multiple analyzers are deployed simultaneously 2) analytical performance goals compatible with clinical use and the state of the art for all parameters.