CLINICAL EVALUATION

A. Diffusion Limitation

1. Direct measurement of D_O2

D_O2 = V'_O2 / ( P_A-O2 - P_{pul cap O2} )

difficult to apply, since P_{pul cap O2} is impossible to measure directly

2. Measure D_CO and use to calculate D_O2

D_CO = V'_CO / ( P_A-CO - P_{pul cap CO} )

but P_{pul cap CO} ≈ 0, since Hb binds CO tightly, so

D_CO = V'_CO / P_A-CO and

D_O2 = 1.23 x D_CO