Distribution of pulmonary blood flow in relation to atelectasis in premature ventilated lambs.

To investigate the ability of the preterm, ventilated lung to redirect blood flow away from atelectatic regions, we studied lambs with respiratory distress syndrome and spontaneous atelectasis or atelectasis caused by bronchial obstruction with a balloon catheter. Pulmonary blood flow distributions were measured by quantifying 15-mu, microsphere-associated radioactivity within multiple pieces of lung. Lambs with well aerated or very atelectatic lungs had relatively uniform blood flow/gram lung in all pieces of lung. Blood flow was much less uniform in lungs with both aerated and atelectatic regions. In 9 lambs with spontaneous atelectasis that included 25 +/- 5% (mean +/- SE) of the lungs by weight, blood flow was 29 +/- 4% less to atelectatic than to aerated lung volumes (p less than 0.01). In 5 lambs with well-aerated lungs, 18 +/- 3% of the lung by weight was made atelectatic by balloon occlusion of a major lower lobe bronchus. There was a 44 +/- 11% decrease in blood flow to the atelectatic lung segments. These studies document the ability of the lung of the premature, ventilated lamb to shunt pulmonary blood flow away from atelectatic lung volumes.

[1]  A. Jobe,et al.  Surfactant and pulmonary blood flow distributions following treatment of premature lambs with natural surfactant. , 1984, The Journal of clinical investigation.

[2]  A. Jobe,et al.  Surfactant pool sizes and severity of respiratory distress syndrome in prematurely delivered lambs. , 2015, The American review of respiratory disease.

[3]  J. Godleski,et al.  Retention of inhaled particles in hamsters with pulmonary fibrosis. , 1983, The American review of respiratory disease.

[4]  A. Jobe,et al.  Cardiovascular Effects of Surfactant Suspensions Given by Tracheal Instillation to Premature Lambs , 1983, Pediatric Research.

[5]  J. Brain,et al.  Anesthesia alters the pattern of aerosol retention in hamsters. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[6]  R. Traystman,et al.  Mechanical factors and the regulation of perfusion through atelectatic lung in pigs. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[7]  B. Marshall,et al.  Hypoxic pulmonary vasoconstriction in dogs: effects of lung segment size and oxygen tension. , 1981, Journal of applied physiology: respiratory, environmental and exercise physiology.

[8]  B. Marshall,et al.  Continuity of response to hypoxic pulmonary vasoconstriction. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[9]  R. Traystman,et al.  Sublobar atelectasis and regional pulmonary blood flow. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[10]  J. Benumof.  Mechanism of decreased blood flow to atelectatic lung. , 1979, Texas reports on biology and medicine.

[11]  J I Hoffman,et al.  Blood flow measurements with radionuclide-labeled particles. , 1977, Progress in cardiovascular diseases.

[12]  M. Heymann,et al.  Morphological Development of the Pulmonary Vascular Bed in Fetal Lambs , 1976, Circulation.

[13]  P. Kadowitz,et al.  Effects of alveolar and perfusion hypoxia and hypercapnia on pulmonary vascular resistance in the lamb. , 1975, The American journal of physiology.

[14]  D. Woodrum,et al.  Gas exchange in the immature lung. I. Anatomical shunt in the premature infant. , 1974, Journal of applied physiology.

[15]  R. Greenspan,et al.  Effects of acute lobar atelectasis on pulmonary hemodynamics. , 1972, Investigative radiology.

[16]  W. Guntheroth,et al.  Pulmonary blood flow and resistance during acute atelectasis in intact dogs. , 1970, Journal of applied physiology.

[17]  J. W. Shaw,et al.  Changes in the Pulmonary Circulation after Bronchial Occlusion in Anesthetized Dogs and Cats , 1969, Circulation research.

[18]  N. M. Nelson,et al.  Uniformity of ventilation in the newborn infant: direct assessment of the arterial-alveolar N2 difference. , 1969, Pediatrics.

[19]  R. Grover,et al.  Comparison of hypoxia, pH, and sympathomimetic drugs on bovine pulmonary vasculature. , 1968, Journal of applied physiology.

[20]  G. Koch.  Alveolar ventilation, diffusing capacity and the A-a PO2 difference in the newborn infant. , 1968, Respiration physiology.

[21]  W. C. Young,et al.  Cardiovascular response of the neonatal lamb to hypoxia and hypercapnia. , 1967, The American journal of physiology.

[22]  W. C. Young,et al.  PATHOPHYSIOLOGY OF RESPIRATORY DISTRESS IN NEWBORN LAMBS. CIRCULATORY, BIOCHEMICAL, AND PATHOLOGICAL CONSIDERATIONS. , 1964, American journal of diseases of children.

[23]  D. Ferguson,et al.  Pulmonary hemodynamics following acute atelectasis. , 1963, The American journal of physiology.

[24]  W. Blakemore,et al.  Effects of atelectasis upon pulmonary blood flow. , 1961, Surgical forum.

[25]  R. M. Peters,et al.  The effects of atelectasis on pulmonary blood flow in the dog. , 1952, The Journal of thoracic surgery.