title: Videodensitometry and chest radiography in the evaluation of pulmonary blood flow and pulmonary oedema in a porcine model of early adult respiratory distress syndrome.
abstract: The adult respiratory distress syndrome was induced in pigs (n = 11) by a continuous infusion of E. coli endotoxin in order to evaluate the use of radiographic videodensitometry and chest radiography for assessment of pulmonary circulation and pulmonary oedema. A further aim was to determine the effect of an ionic contrast medium, Urografin 60%, on extravascular lung water (EVLW). The infusion resulted in a decline in arterial oxygen tension. Mean pulmonary arterial pressure increased, and cardiac output decreased, resulting in a marked rise in pulmonary vascular resistance. EVLW increased moderately. The corresponding variables in control animals (saline infusion; n = 5) changed very little. Good correlations were found (r = 0.87-1.0) between absolute flows as measured by the thermodilution technique and relative flows as determined by videodensitometry in animals with pulmonary damage. In the endotoxin group there was a significant correlation (r = 0.75) between the change in EVLW from baseline to the final measurement (at 6 hours) and the corresponding change in radiographic density. Radiographic signs of pulmonary damage were sparse. Only 3 of 11 animals displayed increased radiographic density of the lung parenchyma indicative of pulmonary oedema. Pleural effusion developed in 4 animals. Injection of Urografin 60%, 1 ml X kg-1, caused a slight but significant decrease in EVLW. We propose that at this concentration and dosage the contrast medium acts mainly as an osmotic diuretic.
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000818:Animals; D001784:Blood Gas Analysis; D001834:Body Water / Q000378:metabolism; D003626:Data Display; D003974:Diatrizoate Meglumine / Q000494:pharmacology; D004195:Disease Models, Animal; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D011652:Pulmonary Circulation; D011654:Pulmonary Edema / Q000000981:diagnostic imaging*; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013552:Swine
chemical_list: D003974:Diatrizoate Meglumine