Accuracy and precision of a point-of-care blood gas analyzer incorporating optodes

Background: A new generation of blood gas analyzers has appeared, and these analyzers are said to be easy to use, portable, battery-powered, and potentially less expensive than conventional systems. These systems allow for point-of-care analysis in emergency rooms, intensive care units, outpatient settings, and transport vehicles. However, the accuracy and precision of these analyzers must be established before they can be used interchangeably with standard laboratory analyzers. We, thus, undertook an evaluation of one such system, the OPTI 1 (AVL Scientific Corporation, Roswell GA). Methods: Two types of evaluation were performed. The first was an analysis of paired- sample measurements on 114 randomly selected patient blood samples using the new system and our standard analyzer. The second analysis consisted of using standard reference material to assess reproducibility (precision) of the analyzer over a 20-day period. Results: In the paired-sample analysis, the correlation coefficients for the values determined by the two systems showed a significant relationship (r = 0.962 for pH, r = 0.9955 for P(CO 2), and r = 0.9829 for P(O 2)). Using the means and standard deviations of the observed differences, in conjunction with Clinical Laboratory Improvement Amendment (CLIA) standards and the 1995 College of American Pathology Blood Gas Survey Reporting data, we calculated that the observed range of differences is within 'interchangeability' ranges. Conclusion: We conclude that the OPTI 1 analyzer has adequate accuracy and precision for use in the clinical arena.

Duke Scholars

Author Neil Ross MacIntyre Jr. Medicine, Pulmonary, Allergy, and Critical Care Medicine