Simple tests of ventilatory capacity in children with cystic fibrosis. I. Clinical and radiological findings in 85 patients. II. Three-year follow-up on 50 patients.

Reports of simple pulmonary function tests in cystic fibrosis first appeared in 1954, when West, Levin, and Di Sant' Agnese showed a characteristic finding in 6 patients, aged 12-16 years, of difficulty in moving air rapidly in or out of the lungs. Cook et al. (1957) studied the lung volume in 53 patients, aged 1-31 years, and found that 810% of those diagnosed as having cystic fibrosis were found to have significant alteration in one or more of the measurements made. A further study (Cook et al., 1959) of 64 patients, aged 6-25 years, over a period of three years related clinical evaluation with results of pulmonary function studies. The vital capacity was found to be below normal in all but 10 patients and the residual volumes increased in 28. Their findings showed no obvious trend, and the authors considered that the duration of the study might have been too short. In 1963, Polgar, Chernick, and Toft reported a longitudinal study over a period of 6 months of pulmonary function in 14 children with cystic fibrosis. They concluded that extreme variability was the limiting factor in evaluating patients with cystic fibrosis by pulmonary function tests. A recent study of 20 children by Beier et al. (1966) showed a pattern of obstructive pulmonary disease, with evidence of increasing airway obstruction paralleling the increase in clinical severity. Correlation between clinical severity and individual pulmonary function tests was also found. The prognosis in cystic fibrosis depends almost entirely on the course of the pulmonary lesion. Clinical and radiological assessment of children with cystic fibrosis attending the Queen Elizabeth Hospital shows that a proportion of those treated intensively for lower respiratory infections from an early age is free or almost free from chronic pulmon-