Неинвазивный метод исследования легочной микроциркуляции

It was found, that at used initial CO concentration in test gas, C0=0.3%, as a result of carboxyheamoglobin (COHb) generation, essential Hb deficiency is created in capillary volume Vc and lung capillary haemodynamics (blood flow Fc ) must be taken into account. Our aim was determination of the relationship between measured values of membrane diffusion capacity, DM , total diffusion lung capacity, DLco , for CO and calculated values of Vc and Fc , taking into account COHb generation. The following equation was derived: C = A/ B x (n1 -n1)/(1 -1/B /(DM /DLco -1)) 1 where n0 and n1are relative (divided on Hb number concentration) initial and final CO number concentrations in alveolar volume VA , at breath holding time t. A, B, c are independent dimensionless parameters: A-θ x VA/DM;B θ xVc/DM;C = Fc x t, and θ is the rate of CO uptake by red cells at known values of Hb and O2 concentrations. Mean relative current COHb concentrations at C0=0.3% are not less then 10% in health and PAH patients, but Vc and Fc values are about 2fold less in PAH patients. We shown, that simultaneous measurement of DM and DLco at two different C0 values allows, except Vc , calculate Fc and may be used for noninvasive investigation of lung haemodynamics.