In patients with acute lung injury of diverse etiologies, diffuse alveolar damage leads to pulmonary edema and acute hypoxemic respiratory failure. Because no specific prevention or treatment of the primary lung injury is available, supportive therapy consists of positive pressure ventilation with high levels of end-expiratory pressure (Peep) and inspired oxygen fraction (FI02) while cardiac output (Qt) is maintined with plasma volume expansion. One adverse outcome of the approach is a non-hypoxic patient with bounding circulation confined to a ventilator awaiting spontaneous clearance of the lung edema while complications of critical illness develop. Conceivably, early aggressive cardiovascular management can reduce extravascular lung liquid (EVLL) without reducing Qt, arterial oxygen transport (QO2) and tissue oxygen utilitization (VO2). This application describes four proposals to evaluate aspects of this approach. 1) In canine models of acid aspiration and lung contusion, pulmonary wedge pressure (Ppw) will be reduced from 10 to 5 torr by plasmapheresis to determine the effect on EVLL, and vasoactive drugs (nitroprusside or dopamine) will be infused to determine whether Qt, QO2, and VO2 can be maintained at low Ppw without adverse effects on lung gas exchange. 2) The effect of reducing Qt by plasmapheresis on the critical value of QO2 needed to maintain aerobic metabolism will be studied before and after acute lung injury is induced in dogs by intravenous oleic acid and again during treatment with Peep or vasoactive drugs. 3) The Starling relationship of the left ventricle is depressed in canine oleic acid pulmonary edema, and this dysfunction is corrected by nitroprusside. To determine whether these effects are due to the acute lung injury, to direct effects of oleic acid on the myocardium, or to effects of altered resistive afterload, we will compare them with corresponding effects on Starling relationships and on isovolemic contractility after left atrial injection of oleic acid which does not cause lung damage. These results will demonstrate whether this cardiovascular management effectively reduces EVLL in diverse canine models of acute lung injury, and how the management is affected by potential cardiovascular depression and by potential changes in the limits of aerobic metabolism. 4) Then we will test whether plasmapheresis (to lower Ppw) and dopamine (to maintain cardiac output) reduce EVLL and the duration and complications of intensive care in patients with acute hypoxemic respiratory failure.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL030835-03
Application #
3341845
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1983-07-01
Project End
1986-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
3
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of Chicago
Department
Type
Schools of Medicine
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
Yanos, J; Wood, L D; Davis, K et al. (1993) The effect of respiratory and lactic acidosis on diaphragm function. Am Rev Respir Dis 147:616-9
Walley, K R; Ford, L E; Wood, L D (1991) Effects of hypoxia and hypercapnia on the force-velocity relation of rabbit myocardium. Circ Res 69:1616-25
Nahum, A; Wood, L D; Crawford, G et al. (1990) Pathogenesis of pulmonary edema associated with intracisternal endotoxin in dogs. J Appl Physiol 68:1688-95
Yanos, J; Keamy 3rd, M F; Leisk, L et al. (1990) The mechanism of respiratory arrest in inspiratory loading and hypoxemia. Am Rev Respir Dis 141:933-7
Humphrey, H; Hall, J; Sznajder, I et al. (1990) Improved survival in ARDS patients associated with a reduction in pulmonary capillary wedge pressure. Chest 97:1176-80
Presberg, K W; Sznajder, J I; Melendres, J et al. (1990) Distribution of pulmonary vascular resistance during lactic acid infusion in dogs. J Appl Physiol 68:1328-36
Corbridge, T C; Wood, L D; Crawford, G P et al. (1990) Adverse effects of large tidal volume and low PEEP in canine acid aspiration. Am Rev Respir Dis 142:311-5
Walley, K R; Lewis, T H; Wood, L D (1990) Acute respiratory acidosis decreases left ventricular contractility but increases cardiac output in dogs. Circ Res 67:628-35
Teplinsky, K; O'Toole, M; Olman, M et al. (1990) Effect of lactic acidosis on canine hemodynamics and left ventricular function. Am J Physiol 258:H1193-9
Yanos, J; Presberg, K; Crawford, G et al. (1990) The effect of hypopnea on low-pressure pulmonary edema. Am Rev Respir Dis 142:316-20

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