The DeltaCrit System (DCS): a computer program for standardized bedside detection of critical oxygen delivery using the Deltatrac II metabolic monitor.

Under resting conditions oxygen consumption (VO2) of the tissues equals their O2 demand. However, when oxygen delivery (DO2) decreases below "a critical" value, the consecutive decline of VO2 reflects a critical restriction of DO2 resulting in the onset of tissue hypoxia. Reliable bedside detection of a significant VO2 decline requires continuous measurement of in- and exspiratory O2 concentrations with a metabolic monitor as well as a standardized online analysis of the data obtained. However, for this purpose no standardized procedure was available yet. Therefore, the DeltaCrit-System (DCS) has been developed enabling online detection of a significant VO2 decline indicating critical restriction of DO2. After a reference period with stable VO2 values the DCS tests whether a subsequently measured VO2 value is significantly lower than the mean baseline VO2. A significant VO2 decrease should indicate the onset of O2 supply dependency of VO2 due to a critical restriction of DO2. The DCS has been validated with nine different, artificially generated data sets and has been tested in one animal experiment. DCS has proven consistency and may therefore be considered a new tool allowing clinicians to recognize restrictions in DO2 at an early time, and to start early therapeutic interventions.