Continuous intra-arterial blood-gas monitoring

Abstract

Objective: To review the technology and the role of continuous intra-arterial blood gas monitoring in critical illness. Data sources: Articles and published peer review abstracts on continuous intra- arterial blood gas monitoring. Summary of review: The history of intermittent and continuous blood gas analysis and the development of technology of continuous blood gas monitoring are reviewed. A summary of the various clinical trials on the evaluation of continuous blood gas monitoring systems, and the various factors which might affect the performance characteristics in the clinical setting is also presented. The potential role and future applications of this technology in critical illness are described. Conclusions: Over the last 10 years, a number of continuous intra-arterial blood gas monitoring systems have been developed. Only a few have reached commercial availability. While the performance characteristics of these systems are comparable, the levels of accuracy of these systems obtained in vitro are not consistently obtained in clinical trials. Arterial blood flow, wrist movement, wall effect and variability of blood gas analysers are some of the factors which determine the accuracy and reproducibility of these systems. Evidence to support the clinical usefulness of these monitors exists only in the form of case studies. Controlled studies demonstrating an improvement in outcome with the use of these monitors are lacking. (author abstract)