Indicator dilution measurements of extravascular water in the lungs

摘要: Multiple indicator dilution studies of the pulmonary circulation were carried out in conscious, resting and exercising, anesthetized dogs under conditions where there was no edema. Labeled red cells, water, albumin injected together into artery, effluent patterns obtained from descending thoracic aorta. The product mean transit time differences between labeled water flow used to estimate extravascular parenchymatous water; this expressed as a proportion content blood-drained lung at postmortem examination. These estimates proportional found increase with flow, approach an asymptotic value. Reconsideration capillaries, however, led postulate that should be calculated, utilizing appropriate vascular reference substance uniformly labels cells plasma, which is confined circulation, rather than tracer only cells. approximated by sum times albumin, each weighted according blood present phase. values for so computed also increased appeared asymptote corresponded approximately two-thirds wet weight. estimated space after pentobarbital anesthesia lower conscious animals. When animals bled, disproportionately large, relation previous values. experimental results support hypothesis dilutional reflect capillary filling; filling increases exercise; relative occurs part response hemorrhage.