Am. J. Respir. Crit. Care Med.,
Volume 158, Number 6, December 1998, 1715-1723
In Vivo Quantitation of Epithelial
Lining Fluid in Dog Lung
SAM
BAYAT,
AHMED
MENAOUAR,
DANIEL
ANGLADE,
HENRY
ETTINGER,
ANNE
FRANÇOIS-JOUBERT,
GILA
BENCHETRIT,
and
FRANCIS A.
GRIMBERT
Unité Mixte de Recherche 5525 du Centre National de Recherche Scientifique, Service de Médecine Nucléaire, Centre Hospitalier
Universitaire de Grenoble, Institut des Sciences et Techniques de Grenoble, Université Joseph Fourier, Grenoble, France
We used an original saturation bronchoalveolar lavage (SBAL) technique (Eur. Respir. J. 1995;8[Suppl.
19]398S) to quantitate lung epithelial lining fluid volume (VELF) in dogs in two separate experiments:
control and after oleic-acid-induced injury. We confirmed the hypothesis that 99mTc-DTPA, infused at
constant plasma activity, reaches equilibrium with epithelial lining fluid after 90 min. We performed
eight sequential lavages 215 min after beginning the infusion of 99mTc-DTPA. 99mTc-DTPA activity
(Qn) in the lavage fluid increased linearly with time, suggesting transport from the plasma into the alveoli during lavage. We extrapolated Qn to time zero (Q0), when 99mTc-DTPA was not affected by lavage. VELF was calculated from: VELF = Q0/Cp, (Cp: 99mTc-DTPA mean plasma activity). 125I-albumin was
used as a nondiffusible alveolar indicator to measure the fluid volume present in the lavaged segment (Vt,n). Vt,n plateaud for n 
4. VELF/
t,n(n = 5,8) was 1.7 ± 0.4 and 25.0 ± 4.4% (p < 0.05) in control and injury experiments, respectively. SBAL allowed reliable measurements of VELF and detection of
alveolar edema fluid in the injured lung.
