In vivo measurement of lung capillary-alveolar macromolecule permeability by saturation bronchoalveolar lavage.
OBJECTIVE
Measurement of capillary-alveolar permeability to fluorescein isothiocyanate-dextran (FITC-D) (molecular mass, 71,300 daltons) by a sequential bronchoalveolar lavage (BAL) technique.


METHODS
Animal research.


METHODS
The Department of Physiology at a scientific and medical university.


METHODS
Nine anesthetized and mechanically ventilated dogs.


METHODS
Two separate experiments were performed in each subject-an initial control experiment followed by an oleic acid-induced lung injury. The indicator was administered at constant blood concentration before serial BAL including eight fluid instillation-recovery cycles.


METHODS
Plasma to BAL solute clearance at saturation (capillary-alveolar clearance at saturation, mL/min) was calculated and normalized to lavage fluid volume (measured by 1251 serum albumin dilution) to obtain a transport rate (TR) constant.


RESULTS
TR for FITC-D70 was 4.0+/-0.8 and 46.1+/-18.1 x 10(-5) x min(-1) in control and injured lung, respectively (p < .02). Capillary-alveolar clearance of FITC-D70 was not affected by the lavage procedure itself. TR reflected essentially epithelial permeability in normal lung and combined epithelial and endothelial permeability in injured lung. A significant correlation was found between cardiac output and TR in injured lung.


CONCLUSIONS
Saturation BAL allowed us to estimate capillary-alveolar macromolecule permeability in vivo in dogs. Further study may allow bedside evaluation of lung injury by BAL in patients.
Bayat
S
S
Unité Mixte de Recherche 5525, Centre National de Recherche Scientifique, Université Joseph Fourier, Grenoble, France.
Anglade
D
D
Menaouar
A
A
Martiel
J L
JL
Lafond
J L
JL
Benchetrit
G
G
Grimbert
F A
FA
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D002199:Capillary Permeability / Q000502:physiology*; D004285:Dogs; D016650:Fluorescein-5-isothiocyanate / Q000493:pharmacokinetics*; D005456:Fluorescent Dyes / Q000493:pharmacokinetics*; D006439:Hemodynamics; D011650:Pulmonary Alveoli / Q000502:physiology*
D005456:Fluorescent Dyes; D016650:Fluorescein-5-isothiocyanate