Multiple inert gas elimination technique in interstitial lung disease: analysis of ventilation - perfusion relationship

There aerI.' stilI few studies on the mechanisms underlying arterialhypoxemia in interstitial lung disease , From these studies arterialhypoxemia was suggested to be a result of various mechanisms: thethickening of alveolar interstitium which reduces the diffusing capacityfor oxygen (l, 2); the reduction of alvleolar capillary bed(3); thealteration of alveolar capillary membranes in a non uniform manner, thuscausing a ventilation-perfusion mismatching (4); the low mixed venousoxygen tension due to low values of cardiac output and the short,ned timI.'available for diffusion of oxygen across the alveolar-capillary membranedue to pulmonary vascular involvement present in advanced interstitial lungdisease (:5, 6).Our pr.sent study was therefore performed with the aim to analyse theprobable causes of hypoxemia in patient with interstitial lung disease bythe assessment of ventilation-plerfusion relationships from multiple inertgas technique (4). This method is a useful approach for the evaluation ofpulmonary gas exchange and, in particular, for the analysis of therelationships between the distribution of ventilation (V) and perfusion (Q)in respect to their V/Q ratio.In this brief paper the preliminary results on three patients have beenreported.