The physiology of leaky lungs

Abstract

We are now in a position to measure, with a minimally invasive test, an index of pulmonary epithelial permeability which is very sensitive to epithelial damage. It remains to be established how much T( 1/2 LB) must decrease to indicate incipient pulmonary oedema. The lowest value of T( 1/2 LB) that we have seen in symptomless smokers was 6 min and the T( 1/2 LB) in the fast component of patients with shock lung was 2±1 min. To improve the predictive power of the test for pulmonary oedema it is likely that a tracer with a larger molecular weight will be needed. In its present form, however, the test is already a considerable advance on pre-existing techniques.