Heterogeneous ventilation and perfusion: a sensitive indicator of lung impairment in nonsmoking coal miners.
Twenty life-long nonsmoking West Virginia coal-miners participated in a study to amplify the role of focal irregularities on regional ventilation (V) and perfusion (Q) and to develop an improved method for the early detection of coal-workers' pneumoconiosis. Their mean age was 59.3 yr and they averaged 35.2 years' exposure to coal dust. Conventional pulmonary function tests were supplemented by measurement of V, Q and lung volume (V), using radioactive Kr-81m, Tc-99m MAA and Xe-127, respectively, to determine regional abnormalities in lung function. A computer analysis of the regional distributions of V/V, Q/V and V/Q was performed, and their topographical distributions and indices of heterogeneity (HI) computed. V/V and Q/V were significantly reduced in the lower third, and increased in the upper two-thirds of the miners' lungs; V/Q was reduced in the upper half. The miners' V/V and Q/V were more heterogeneous (p less than 0.001) than that of eleven age-matched controls, with mean ventilation HI values of 0.190 +/- 0.027 and 0.133 +/- 0.011, respectively, and mean perfusion HI values of 0.206 +/- 0.022 and 0.164 +/- 0.041, respectively. P(A-a)O2 correlated positively (r = 0.72; p less than 0.001) with ventilation HI. Gas exchange was the most significant functional measurement, being abnormal in 19/20 subjects. In contrast, conventional spirometric measurements were within the predicted normal limits in all but four miners.
Susskind
H
H
Medical Research Center, Brookhaven National Laboratory, Upton, New York 11973.
Acevedo
J C
JC
Iwai
J
J
Rasmussen
D L
DL
Heydinger
D K
DK
Pate
H R
HR
Harold
W H
WH
Brill
A B
AB
D000328:Adult; D000368:Aged; D003032:Coal Mining; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011009:Pneumoconiosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011877:Radionuclide Imaging; D012129:Respiratory Function Tests; D012907:Smoking / Q000503:physiopathology; D013147:Spirometry; D014692:Ventilation-Perfusion Ratio