Relationship between functional and X-ray alterations in patients with cystic fibrosis

BACKGROUND: Cystic fibrosis (CF) is a disease marked by airway inflammation and airflow obstruction, resulting in air trapping in the lungs. OBJECTIVE: To assess the associations between airflow limitation, pulmonary volume and X-ray findings in patients with cystic fibrosis. METHOD: A cross-sectional retrospective study. Review of spirometric, plethysmographic, and chest X-ray findings of outpatients (age ³ 16 years). The airflow findings were classified as within normal limits or as airflow obstruction: mild, moderate or severe obstructive alteration. RESULTS: A total of 23 patients (15 male and eight female; mean age, 21 ± 5.9 years) were studied. Six of them were within normal limits, four had a mild, five had a moderate, and eight had a severe obstructive alteration. There was an association between airflow limitation and the increase of residual volume (p = 0.006) and also with the Brasfield score (p = 0.001), but not with the total lung capacity (p = 0.33). There was a correlation between residual volume and Brasfield score (r = 0,73, p = 0,002), but not with the total pulmonary capacity. Moreover, according to X-ray criteria, the air trapping was correlated only with the residual volume (p = 0.006). CONCLUSION: In patients with cystic fibrosis (age ³ 16 years), the progressive airflow limitation is accompanied by an increase in residual volume, while the total pulmonary capacity remains normal or tends to decrease. The X-ray score was associated with airflow limitation and residual volume, but not with total lung capacity.