Regional Ventilation-Perfusion and Hypoxia in Cryptogenic Fibrosing Alveolitis1,2

The relationship of regional ventilation and perfusion and closing volume to hypoxemia has been studied in 10 patients with interstitial lung disease of the fibrosing alveolitis type. the regional distribution of ventilation was only moderately impaired, but there was a marked reversal of the normal pattern of regional lung perfusion. Phase III of the nitrogen washout curve was abnormal in 6 patients and closing volume was reduced in 3 of 4 patients in whom a measurable pattern of nitrogen washout was obtained. the degree of hypoxemia appeared to be related to the severity of disturbance in regional lung perfusion and not to the degree of ventilatory impairment, the pattern of the nitrogen washout, closing volume, or the regional distribution of ventilation. Increase in perfusion to the lung bases after treatment with corticosteroids was accompanied by an improvement in blood gases.