Exercise capacity in adolescent and adult patients with post infectious bronchiolitis obliterans

Post-infectious bronchiolitis obliterans (PBO) is a chronic lung disease characterized by the persistence of continuous obstructive respiratory symptoms following an acute and severe respiratory infection in children under 3 years old. The purpose of the present study was to investigate if adolescents and adults with diagnosis of PBO have reduced aerobic capacity and identify factors related with exercise performance.

A convenience sample of 16 patients (10-23 years) that have consulted with established diagnosis of PBO in a tertiary care clinic were studied. Fourteen healthy matched subjects were selected from the community to serve as controls. They performed resting lung function tests and cycle incremental cardiopulmonary exercise tests.

Peak aerobic capacity (peak V˙O(2)) was significantly lower in patients compared to controls (84 ± 15 vs. 101 ± 17% pred; P < 0.01). Peak V˙O(2) was correlated with rest inspiratory capacity (IC) (r = 0.60; P = 0.02) and marginally with forced expiratory volume in the first second (FEV(1)) (r = 0.45; P = 0.09). Additionally, FEV(1) was correlated with IC (r = 0.83; P < 0.01) and residual volume/total lung capacity (r = -0.91, P < 0.01).

Adolescent and adult patients with PBO had reduced peak V˙O(2) compared to healthy controls. Peak V˙O(2) was correlated with parameters of airflow limitation and rest hyperinflation. The greater the air flow limitation (lower FEV(1)) the greater the hyperinflation, air trapping, and aerobic capacity reduction.