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R Dozor

Publications and source records attributed to R Dozor.

4 recordsLinked to original sources
PubMed1979

Effect of static or slowly flowing blood on carbon monoxide diffusion in dog lungs.

During temporary left pulmonary artery occlusion (TLPAO) in dogs, blood in pulmonary capillaries downstream from the occlusion is static or flowing slowly. In such areas, the uptake of carbon monoxide (CO) and diffusing capacity (DLCO) should decrease with time as carboxyhemoglobin concentration increases. We measured DLCO during exhalation of five sequential breaths in anesthetized dogs using a modification of a technique recently described in our laboratory (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 43: 617--625, 1977). During TLPAO, the decrease in DLCO was greatest at low lung volumes, suggesting that the occluded lung was emptying later in exhalation, a conclusion supported by measurements of DLCO during TLPAO with the right mainstem bronchus occluded. In addition. DLCO decreased with each breath as the backpressure to diffusion increased in static capillary blood. Inhalation of 4% CO accelerated the rate of decrease in DLCO. Measurement of DLCO during exhalation over multiple breaths may help detect pulmonary vascular obstruction.

Animals↗
PubMed1979

The clinical usefulness of a screening test to detect static pulmonary blood using a multiple-breath analysis of diffusing capacity.

We devised a screening test to detect static blood in the lungs (e.g., with pulmonary vascular obstruction or pulmonary hemorrhage). A back pressure to CO will develop in static blood as the concentration of carboxyhemoglobin increases with time, and diffusing capacity (DLCO) will decrease. Instead of obtaining a single value for DLCO, we calculated DLCO over small decrements of the exhaled vital capacity during 4 sequential breaths using a modification of a method developed in our laboratory. In each of 5 healthy subjects there was no difference in DLCO during the 4 sequential breaths in the sitting, supine, or lateral decubitus positions. However, in a patient with a proved pulmonary embolus, DLCO decreased with sequential breaths, expecially at low lung volumes. In a patient with angiographic evidence of kinking of the left pulmonary artery when he assumed the right lateral decubitus position, DLCO showed a sequential decrease in this position only. Three patients with pulmonary hemorrhage also showed decreases in DLCO during sequential breaths during episodes of active bleeding.

Adult↗