Recruitment of lung diffusing capacity: update of concept and application.
Lung diffusing capacity (DL) for carbon monoxide (DLCO), nitric oxide (DLNO) or oxygen (DLO2) increases from rest to peak exercise without reaching an upper limit; this recruitment results from interactions among alveolar volume (VA), and cardiac output (q), as well as changing physical properties and spatial distribution of capillary erythrocytes, and is critical for maintaining a normal arterial oxygen saturation. DLCO and DLNO can be used to interpret the effectiveness of diffusive oxygen transport and track structural alterations of the alveolar-capillary barrier, providing sensitive noninvasive indicators of microvascular integrity in health and disease. Clinical interpretation of DL should take into account Q in addition to VA and hemoglobin concentration.
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Connie C W
CC
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas TX 75390-9034, USA.
D004912:Erythrocytes; D015444:Exercise; D006331:Heart Diseases / Q000503:physiopathology; D006400:Hematocrit; D006801:Humans; D008171:Lung Diseases / Q000503:physiopathology; D011650:Pulmonary Alveoli; D011653:Pulmonary Diffusing Capacity / Q000502:physiology