Principles of oxygen transport in the critically ill obstetric patient.

Invasive hemodynamic monitoring is commonly used in critically ill patients in whom cardiorespiratory compromise is evident. The information acquired assists the clinician in the assessment of cardiac and intravascular status. However, many patients have complex pathophysiologic conditions that dictate the evaluation of their oxygen transport system. This article provides a discussion of the principles of oxygen transport, including the concepts of oxygen content, oxygen affinity, oxygen delivery, and oxygen consumption. Clinicians providing care for critically ill pregnant women should have a thorough understanding of the physiology of oxygen transport, its alterations in specific disease process, and interventions necessary to improve the individual components of oxygen transport.