D1.475 - Significance of air-trapping and pulmonary hyperinflation in the severity of broncho-obstructive manifestations in children with cystic fibrosis

Cystic fibrosis (CF) is a severe autosomal recessive genetic disorder caused by mutations of the CFTR gene, resulting in impaired epithelial ion transport and viscous secretions. Pulmonary involvement represents the main cause of morbidity and mortality in pediatric CF patients. Chronic airway inflammation, mucus retention, and recurrent infections lead to progressive airflow limitation. Broncho-obstructive phenomena, including air trapping and pulmonary hyperinflation, reflect early small airway dysfunction and play a crucial role in disease progression, often preceding significant spirometric decline. Thus, body plethysmography comes in as a more sensitive method for detecting these ventilatory abnormalities, allowing for a more precise assessment of lung volumes and airway resistance.

Aim.To assess broncho-obstructive syndrome in children with cystic fibrosis using body plethysmography.

Body plethysmographic evaluation was performed in 15 children with CF. The diagnosis was confirmed by positive sweat tests and molecular investigations of CFTR mutations. The mean age was 11.26 ± 2.89 years (range: 8–17 years).

Body plethysmography provided a detailed characterization of functional respiratory impairment in CF patients. Reduced total lung capacity (TLC), indicative of restrictive impairment, was identified in 13.3% of patients. Increased residual volume (RV) with normal TLC, consistent with air trapping, was observed in 5 cases (33.3%). The association of increased RV with increased TLC, reflecting pulmonary hyperinflation, was observed in 8 patients (53.3%) evaluated by body plethysmography.

An important parameter of pulmonary functional assessment is the diffusing capacity of the lung for carbon monoxide (DLCO), a sensitive indicator of interstitial lung involvement. Reduced DLCO was identified in 6 patients (54.5%). Among these, mild, moderate, and severe reductions were equally distributed, each observed in 2 patients (18.2%).

Broncho-obstructive phenomena in children with cystic fibrosis are predominantly characterized by pulmonary hyperinflation rather than isolated air-trapping mechanisms. Body plethysmography enables a comprehensive understanding of airway pathophysiology in pediatric patients with cystic fibrosis