Work

Indicator dilution lung water and vascular permeability in humans. Effects of pulmonary vascular pressure.

Year: 1979

Type: article

Abstract: To see whether a multiple-indicator dilution technique would measure lung vascular permeability and extravascular lung water (EVLW) in humans, we did indicator studies during cardiac catheterization in 18 patients with various degrees of stable heart failure.A mixture of "Cr-erythrocytes, '"I-albumin, 'H-water, and u C-urea was injected into the right atrium, and serial blood samples were taken from an arterial catheter.From the time-concentration curves we calculated cardiac output, 14 C-urea permeability-surface area product (PS) (by both integral extraction and a Krogh-convolution model), and EVLW (by both mean transit time and a Krogh-convolution model).We also calculated lung microvascular pressure (Pmv) from pulmonary artery and pulmonary artery wedge or left atrial pressures, and measured hematocrit, plasma protein concentration, lung vital capacity, total lung capacity (TLC), carbon monoxide-diffusing capacity, and alveolar volume (VA).14 C-urea PS correlated well with V A 1/S (r -0.62, P -0.019).Urea PS/V A l/l did not correlate with P mv (r -0.36, P -NS), hematocrit (r --0.07,P = NS), or cardiac output (r -0.36, P -NS).EVLW/TLC correlated with P ra» (r = 0.51, P -0.02) and even better with P mv -plasma oncotic pressure (r -0.63, P -0.007).We therefore conclude that "C-urea PS is a measure of lung vascular permeability in humans, and that, as in animals, permeability is unaffected by P mT .EVLW may be a more useful measure of lung water in humans than previously thought, when interpreted in light of the measurable forces affecting fluid exchange.Circ Res 44: 523-530, 1979SOMETIMES excess fluid accumulates in the lung primarily because of changes in the lung circulation (Brigham et al., 1974).When humans develop pulmonary edema while lung vascular pressures are low, it is inferred that lung exchanging vessels are leaking too much fluid and protein (increased permeability; see Robin et al., 1968Robin et al., , 1973)).

Source: Circulation Research

DOI: 10.1161/01.res.44.4.523