Journal of Applied Physiology, Vol 39, Issue 5 843-845, Copyright © 1975 by American Physiological Society
Rapid estimation of pulmonary extravascular water with an instream catheter
W. P. Anderson, L. J. Dunegan, D. C. Knight, G. F. Fitzpatrick, N. E. O'Connor and A. P. Morgan
An arterial catheter-bearing external conductivity electrodes and a
thermistor was used for measurement of lung thermal volume (LTV) by the
double-indicator method. Ten milliliters of 3% saline at room temperature
were injected, dilution curves measured, and LTV calculated as mean transit
time difference, less thermistor time constant, times cardiac output (CO).
Comparisons were made, in dogs, between LTV, pulmonary extravascular lung
water with Evans blue and tritiated water (PEVWtho), and weighed lung water
(WLW). Pulmonary edema was induced with dextran and epinephrine. CO was
measured by thermodilution in both the pulmonary artery (PA) and aorta (AO)
and dye dilution in the AO. CO from dye dilution was compared with
thermodilution (aortic detection) to detect irreversible loss of thermal
indicator. Comparisons showed good correspondence of dye and thermal curves
(Y = 0.91X - 0.16 1/min; r = 0.93). LTV is about 120% of WLW in near normal
lungs, 90% of WLW in extreme edema. PEVWtho was 60-70% WLW.
