Relationship between clinical conditions, radiographic findings and pulmonary functions in patients with cystic fibrosis.

Clinical and radiological findings, quantified by special scores, in 36 patients with cystic fibrosis are compared with lung function measurements, including the ratio of RV/TLC and FEV/VC and the arterial blood gases at rest and during exercise. Although respiratory function tests were found to correlate well with both the pulmonary finding score and the chest radiographic score, distinction of three severity groups was possible only by a vector calculation of the blood gases in PaO2-PaCO2-diagram, at rest and during exercise. Thus, measurements of pO2 and pCO2 at rest and on exercise appear to be a helpful adjuvant to routine spirometry for the individual appraisal of the degree of lung involvement, performance and care level.