Читать книгу Respiratory Medicine - Stephen J. Bourke - Страница 88

Clearly, T_LCO can be reduced by a number of disease processes within the lung. It is also reduced if there is simply ‘less lung’ (a reduced lung volume) participating in gas transfer (e.g. respiratory muscle weakness causing restriction or after pneumonectomy). It would be useful to be able to distinguish between these two very different mechanisms.

Transfer coefficient (KCO) is the transfer factor divided by V_A. This tells us the transfer factor ‘per unit lung volume’. Like T_LCO, KCO is reduced when there is intrinsic lung disease, but unlike T_LCO, KCO is not diminished when a healthy lung is reduced in volume by some external factor.