Blood gas/pH analyzers.

Blood gas/pH analyzers (BGAs) measure or calculate several physiologic parameters, typically from an arterial blood sample, to assist clinicians in diagnosing, assessing, and monitoring the patient's condition (e.g., respiratory status) and regulating therapy (e.g., ventilation). In this study, we focused on the use of BGAs in two different settings: (1) centralized testing locations that service several different hospital departments or areas and (2) decentralized, sometimes referred to as "point-of-care," testing areas. (Also refer to the Guidance Article, "Point-of-Care' Laboratory Testing: Is Decentralized Testing the Best Alternative for Your Hospital?" in this issue). In this Evaluation, we evaluated seven GBAs from seven manufacturers, examining the appropriateness of each device for use by the two types of potential users: (1) specialized personnel (e.g., medical technologists) experienced in using and maintaining laboratory equipment and (2) nonspecialized personnel (e.g., nurses) who do not have such experience but may be expected to operate the devices in facilities using a decentralized testing program. We rated each unit separately for these two user types to help facilities choose the unit that best fits their testing program. Note that we did not test all capabilities of these units; for example, we did not test electrolyte or other metabolite determinations or the accuracy of derived (i.e., calculated) parameters. Our ratings were based largely on whether a BGA could report erroneous derived parameters. We also considered the level of operator maintenance required, as well as cost and human factors issues, when ranking the units within their ratings group. Only one unit was rated Acceptable for use by either specialized or nonspecialized personnel. The remaining units were rated Conditionally Acceptable because they could present erroneous values for one or two derived parameters. Our conditions of acceptability include (1) that the parameter(s) in question be determined by using a multiwavelength oximeter or (2) that the BGA not report results for these parameters. (Although we did not evaluate oximeters in this study, we did test the accuracy of one oximeter parameter on the one evaluated BGA that contains an integral oximeter.)