HUMAN BRONCHIAL PERFUSION EVALUATED WITH ENDOSCOPIC LASER-DOPPLER FLOWMETRY

Endoscopic laser Doppler flowmetry (LDF) was used to study human bronc hial microvascular perfusion in 25 healthy subjects. In total 617 reco rdings with good signal to noise ratio were obtained and, in the hands of an experienced bronchoscopist, the procedure did not cause major t echnical problems. Curve fluctuations synchronous to heart rate and re spiration were identified. The spatial variation of measurements in on e region was considerable, but when the mean of four measurements was used, acceptable precision levels were obtained. Regional differences were observed between 40.3 arbitrary perfusion units (PU) (34.0-46.6) in the right upper lobe bronchus and 77.3 PU (63.6-91.0) at the main c arina. Measurements were obtained from the main carina, the right uppe r lobe bronchus, the apical segment of the right and left lower lobe b ronchus. Tn all bronchi, recordings were performed at two locations di stal to the bifurcation; 1-5 mm (central) and 6-10 mm (peripheral). Th e peripheral flux revels were significantly higher than the central (p <0.001). Analysis of the short and long term temporal variation showed no significant differences, when the data was analyzed on a group bas is. We conclude that LDF seems to be a promising method for future cli nical investigations.