Extrinsic allergic alveolitis caused by pigeon breeding at a high altitude (2,240 meters). Hemodynamic behavior of pulmonary circulation

The hemodynamic characteristics of the pulmonary circulation were examined in 10 patients with proved extrinsic allergic alveolitis caused by pigeons (EAA-P) raised at a high altitude. All patients had lung biopsies that showed an interstitial inflammatory response with vascular lesions. At rest, all patients had mean pulmonary pressures (PAP) greater than 16 mmHg; the average PAP was 22 ± 12 mmHg for the whole group. Pulmonary vascular resistance was high and the mean for the whole group was 225 ± 25 d.s.cm^-5. The pulmonary artery diastolic-pulmonary wedge pressure (PAd-PWP) difference was elevated and averaged 8.5 ± 2 mmHg. All patients were hypoxemic with elevated AaDO₂. With exercise, both PAP and PAd-PWP increased abnormally. While breathing oxygen (FIO₂, 99.6%) PAP decreased an average of 7 mmHg (p<0.05) and PAd-PWP decreased an average of 5 mmHg (p<0.05) without a significant change in PWP. The calculated compliance of the elastic pulmonary arteries in EAA-P was not different from that in normal subjects. Alveolar hypoxia produced mainly by EAA-P and presumably enhanced by living at a high altitude appeared to be the factors in the genesis of pulmonary hypertension, because pulmonary artery diastolic pressure and PAd-PWP difference were correlated with arterial oxygen saturation.