Blood Gas Monitoring with Optodes

Abstract

Assessment and management of critically ill patients requires frequent arterial blood gas and pH measurement. There are drawbacks associated with this measurement. Since indications for sampling are vague, arterial blood gas analysis provides only an isolated snapshot of a continuous physiological process and moreover is often performed after a deleterious event has occurred. This has led to the argument that clinical decisions should be made on the basis of trends in blood gases. Coupled with the considerable variability in arterial blood gases that occurs even in apparently stable patients [1], this ‘reactive’ or intermittent approach is clearly suboptimal. Recently, for example, it has been reported that conventional arterial blood gas analysis can miss substantial changes in arterial blood gases during thoracoscopic surgery [2]. Intermittent sampling is also associated with an increased therapeutic decision time, increased risk for infection (both to the patient and operator), and increased blood loss for the patient.