Forced deflation pulmonary function test: a novel method to evaluate lung function in infants and young children

We describe the safety and feasibility of a forced deflation pulmonary function test (dPFT) in infants and young children. Fifty-two dPFT studies were performed in 26 patients (median age, 1.4 years). Forced vital capacity (FVC) and forced expiratory flow (FEF75) were normal in all except one case, but respiratory system compliance (Crs) was reduced in 24% patients. There were no significant differences in pre-blood and marrow transplantation FVC, FEF75, and Crs between those patients who did and those who did not have posttransplant pulmonary complications. A larger study is needed to determine the prevalence and significance of PFT abnormalities in this age group.