The assessment of respiratory function in a patient with dyspnoea and severe hypoxaemia

In the investigation of dyspnoea and severe hypoxaemia the c1inical relevance of multiple diagnostic techniques was studied. The patient was sequentially studied utilizing several techniques. The degree of lung impairment by spirometry, diffusing capacity for carbon monoxide, haemodynamics, pulmonary gas exchange, ventilation-perfusion relationships assessed by the multiple inert gases elimination techniques, ventilation and perfusion lung scans, gallium 67 scintigraphy, bronchoalveolar lavage and high resolution computerlzed tomography, twice over a perlod or 12 months during recovery under treatment. A marked impainnent of pulmonary gas exchange was first explained by diffusion im- painnent and ventìlatìon-perfusìon mismatch. The multiple inert gas elimination technique alIowed detennination of the cause of hypoxaemia by ventilatìon-perfusion inequality. A pathological correlate or the ventilation-perfusion inequal- ity was the appearance or honeycomb lungs detected by high resolution computed tomograph and active alveolitis by bronchoalveolar lavage. Ali results were consìstent with a diagnosis of fibrosing alveolitis. The patient was evaluated again during treatment. Some functional improvement oc- curred despite persistence or thc same pathological f'mdings. In conclusion, this study demonstrates the value or in- formation derlved from difTerent tests. Physiological correlations complemented by pathological observations expand understanding or the pathogenesis of disease. These procedures contrlbute to understanding mechanisms responsible for functional impairment. Monaldi Arch Chest Dis., 1993; 48: 3, 213-220_