Significance of pathologic oxygen supply dependency in critically ill patients: comparison between measured and calculated methods.

Objective Oxygen supply dependency at normal or high oxygen delivery rate has been increasingly proposed as a hallmark and a risk factor in critical illnesses. We hypothesized that as fas as an adequate oxygen delivery is provided, oxygen consumption, when determined by indirect calorimetry, is not dependent on oxygen delivery in critically ill patients whereas calculated oxygen consumption is associated with artefactual correlation of oxygen consumption and delivery.