title: Comparison of lung vascular and epithelial permeability indices in the adult respiratory distress syndrome.
abstract: Measurements of pulmonary clearance of inhaled 99mTc-DTPA and transvascular 113mIntransferrin flux were made in 12 patients with established ARDS and 14 volunteer control subjects (7 smokers and 7 nonsmokers). Smokers had significantly increased 99mTc-DTPA clearance (clearance rate constant, 3.6 +/- 0.8; mean +/- SEM) compared with nonsmokers (1.2 +/- 0.1). All patients with ARDS had increased clearance of 99mTc-DTPA (5.2 +/- 0.9), but the finding was nonspecific in that increased clearance overlapped with the findings in normal smokers. Protein flux in smokers (protein flux units, 0.0 +/- 0.2) was similar to that in nonsmokers (0.3 +/- 0.2). In 9 of the 12 patients with ARDS, protein flux was increased, and as a group (3.2 +/- 1.0) they differed significantly (p less than 0.01) from the combined smoking and nonsmoking control subjects (0.2 +/- 0.1, n = 14). The parameters of DTPA clearance and transvascular protein flux correlated well in the patients with ARDS (Spearman's rank correlation = 0.71, p less than 0.01). Although 99mTc-DTPA clearance is a sensitive technique in ARDS, a single study in this context does not allow a diagnostic conclusion because of its non-specificity. Abnormal protein flux appears to be more specific for ARDS but was not a universal finding in the patients studied.
mesh_terms: D000328:Adult; D000368:Aged; D002199:Capillary Permeability; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D007204:Indium; D007554:Isotopes; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D004369:Pentetic Acid / Q000097:blood / Q000378:metabolism; D010539:Permeability; D011652:Pulmonary Circulation; D012128:Respiratory Distress Syndrome / Q000378:metabolism*; D013667:Technetium; D014168:Transferrin / Q000097:blood / Q000378:metabolism
chemical_list: D007554:Isotopes; D014168:Transferrin; D007204:Indium; D013667:Technetium; D004369:Pentetic Acid