Prefaut C, Ramonatxo M, Chardon G
Pathol Biol (Paris). 1976 Mar;24(3):209-12.
Lacoste has shown the interest of determination of overall ductance of CO and partial expired alveolar ductance and arterio-alveolar partial ductances in the assessment of the efficacy of gaseous exchanges in the lung. DuCO was, by definition, the product : DuACO X DuaCO, the increase in partial ductance may theoretically compensate reduction in the other, the overall ductance then remains normal. This theory was verified studying the effects of low lung volume ventilation. Under these conditions, the dead space series becomes reduced and the DuACO should increase at the same rate, for ventilation occurs at the level of the closing volume. The inspired air is then directed preferentially towards the lung apices. These artificial changes in distribution of ventilation should produce a reduction in DuaCO. The measurements carried out confirmed these theories during low lung volume ventilation ; whereas the differences observed in overall ductance were not significant, those observed on partial ductance were very definitely significant. It appears that isolated measurement of overall ductance is insufficient and may lead to misdiagnosis of a change in the lung exchanges.
拉科斯特已经表明，在评估肺部气体交换效率时，测定一氧化碳的总传导率、部分呼出肺泡传导率以及动脉-肺泡部分传导率具有重要意义。根据定义，一氧化碳总传导率（DuCO）是部分传导率（DuACO）与动脉-肺泡部分传导率（DuaCO）的乘积：DuCO = DuACO × DuaCO。理论上，部分传导率的增加可能会补偿另一部分的降低，从而使总传导率保持正常。通过研究低肺容积通气的影响，这一理论得到了验证。在这些条件下，死腔系列减少，并且由于通气发生在闭合容积水平，DuACO应该以相同的速率增加。此时，吸入的空气优先导向肺尖。这些通气分布的人为改变应该会导致DuaCO降低。所进行的测量在低肺容积通气期间证实了这些理论；虽然观察到的总传导率差异不显著，但在部分传导率上观察到的差异非常显著。看来，单独测量总传导率是不够的，可能会导致对肺部交换变化的误诊。
