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Oxygenation and mechanisms of hypoxemia

Arthur C Theodore, MD
Section Editor
Polly E Parsons, MD
Deputy Editor
Geraldine Finlay, MD


The process of taking oxygen from the inspired air and using it to sustain aerobic cellular metabolism throughout the body can be conceptualized as having three steps:

Oxygenation is the process of oxygen diffusing passively from the alveolus to the pulmonary capillary, where it binds to hemoglobin in red blood cells or dissolves into the plasma. Insufficient oxygenation is termed hypoxemia. This is to be differentiated from hypoxia, which is an abnormally low oxygen content in a tissue or organ.

Oxygen delivery is the rate of oxygen transport from the lungs to the peripheral tissues.

Oxygen consumption is the rate at which oxygen is removed from the blood for use by the tissues.

Hypoxemia is defined as an abnormally low level of oxygen in the blood (ie, low partial oxygen tension).

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Literature review current through: Nov 2017. | This topic last updated: Nov 07, 2017.
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