Effect of breath-hold time on DLCO(SB) in patients with airway obstruction

• DOI: 10.1152/jappl.1985.58.4.1319
• Publication Date: 2017-12-21T13:16:32Z
• Authors: B. L. Graham; J. T. Mink; D. J. Cotton
• Keywords: DLCO; Pulmonary Diffusing Capacity

The single-breath diffusing capacity of the lung for CO [DLCO(SB)] is considered a measure conductance across alveolar-capillary membrane and its binding with hemoglobin. Although incomplete mixing inspired gas alveolar could theoretically influence overall diffusion, conventional calculations DLCO(SB) spuriously overestimate during short breath-holding periods when within might have greatest effect. Using three-equation method to calculate which analytically accounts changes in breath-hold time, we found that did not change time control subjects but increased increasing both patients asthma emphysema. increase correlated phase III slope N2 washout curve. We suggest ventilation maldistribution, may be decreased shorter maneuvers because diffusion limited by reduced transport from through prior exchange.