Noninvasive blood gas monitoring: a review for use in the adult critical care unit. Technology Subcommittee of the Working Group on Critical Care, Ontario Ministry of Health.
OBJECTIVE
To evaluate the accuracy, reliability, clinical effectiveness and economic impact of bedside pulse oximetry and capnometry as used routinely in the adult critical care environment.


METHODS
The key words "oximetry," "carbon dioxide/analysis" and "evaluation studies" were used to search MEDLINE for all relevant articles published from January 1985 to January 1991.


METHODS
Articles were included for review if they were original research studies designed to clinically evaluate pulse oximetry or capnometry, or both, were published in English and described a critically ill adult population. Eleven articles met these criteria; seven evaluated pulse oximetry, three evaluated capnometry and one evaluated both.


METHODS
The data were evaluated by means of five validity criteria: study setting and subjects, diagnostic accuracy, reliability, clinical effectiveness and economic impact.


RESULTS
No study satisfied all our criteria. Most of the studies were designed to evaluate diagnostic accuracy only, and clinically relevant information was lacking. The accuracy of pulse oximetry was clinically acceptable in five of the eight studies. However, in two of them physiologic extremes, skin pigmentation and an arterial saturation of less than 90% resulted in unacceptable error. The diagnostic accuracy of capnometry was unacceptable.


CONCLUSIONS
Pulse oximetry may expedite accurate and continuous monitoring of oxygenation at the bedside of the critically ill adult patients. Nevertheless, there are clinical limitations, and caution is needed before oximeters are accepted for routine use. The routine bedside use of capnometry should be discouraged.
D000328:Adult; D001784:Blood Gas Analysis / Q000379:methods; D002245:Carbon Dioxide / Q000032:analysis* / Q000097:blood; D003422:Critical Care / Q000191:economics / Q000592:standards*; D005069:Evaluation Studies as Topic; D006801:Humans; D007362:Intensive Care Units / Q000191:economics / Q000592:standards*; D010092:Oximetry / Q000592:standards*; D012119:Respiration; D013673:Technology Assessment, Biomedical
D002245:Carbon Dioxide