Spirometry in early childhood in cystic fibrosis patients.

BACKGROUND: Spirometry data in cystic fibrosis (CF) patients in early childhood is scarce, and the ability of spirometry to detect airways obstruction is debatable.
OBJECTIVE: To evaluate the ability of spirometry to detect airflow obstruction in CF patients in early childhood.
METHODS: CF children (age range, 2.5 to 6.9 years) in stable clinical condition were recruited from five CF centers. The children performed guided spirometry (SpiroGame; patented by Dr. Vilzone, 2003). Spirometry indices were compared to values of a healthy early childhood population, and were analyzed with relation to age, gender, and clinical parameters (genotype, pancreatic status, and presence of Pseudomonas in sputum or oropharyngeal cultures).
RESULTS: Seventy-six of 93 children tested performed acceptable spirometry. FVC, FEV1, forced expiratory flow in 0.5 s (FEV0.5), and forced expiratory flow at 50% of vital capacity (FEF50) were significantly lower than healthy (z scores, mean +/- SD: - 0.36 +/- 0.58, - 0.36 +/- 0.72, - 1.20 +/- 0.87; and - 1.80 +/- 1.47, respectively; p < 0.01); z scores for FEV1 and FVC were similar over the age ranges studied. However, z scores for FEV0.5 and forced expiratory flow at 25 to 75% of vital capacity were significantly lower in older children compared to younger children (p < 0.001), and a higher proportion of 6-year-old than 3-year-old children had z scores that were > 2 SDs below the mean (65% vs 5%, p < 0.03). Girls demonstrated lower FEF50 than boys (z scores: - 2.42 +/- 1.91 vs - 1.56 +/- 1.23; p < 0.001). Clinical parameters evaluated were not found to influence spirometric indices.
CONCLUSIONS: Spirometry elicited by CF patients in early childhood can serve as an important noninvasive tool for monitoring pulmonary status. FEV0.5 and flow-related volumes might be more sensitive than the traditional FEV1 in detecting and portraying changes in lung function during early childhood.