Practical application of oxygen transport principles.

Management of shock is generally guided by hemodynamic data, but the true aim of therapy should be optimizing oxygen delivery (DO2) and consumption (VO2). Available data do not support the hypothesis that there is a single critical threshold of DO2 below which tissue hypoxia occurs; thus, DO2 and VO2 should be addressed for each patient. Interventions that raise BP, such as infused catecholamines, may actually decrease DO2, as can mechanical ventilation with PEEP. Therefore, the clinician should avoid responding solely to hemodynamic data and should direct interventions toward delivering the optimum amount of oxygen to the patient's tissues.