Pulmonary function and morbidity in 40 adult patients with cystic fibrosis.

Pulmonary function and cardiopulmonary complications were studied in a group of 40 patients with cystic fibrosis who reached the age of 25 years. Mean values for vital capacity (VC), functional residual capacity, residual volume (RV), the ratio of RV over total lung capacity (RV/TLC), conductance, and the ratio of the forced expiratory volume in one second over VC were abnormal. There was a variable pattern of progression from patient to patient. The men differed from the women only in that they had a significantly larger TLC and inspiratory capacity than the women. The resultant preservation of VC may have an advantage for survival in those patients in whom it is observed. Pseudomonas aeruginosa was encountered with increasing frequency with age. Massive hemoptysis did not result in early death. The occurrence of rightsided heart failure secondary to cor pulmonale, with or without respiratory failure, was a poor prognostic sign.