Pulmonary function in children and adolescents with postinfectious bronchiolitis obliterans.
OBJECTIVE
To describe the pulmonary function in children and adolescents with postinfectious bronchiolitis obliterans (PIBO), as well as to evaluate potential risk factors for severe impairment of pulmonary function.


METHODS
The pulmonary function of 77 participants, aged 8-18 years, was assessed by spirometry and plethysmography. The following parameters were analyzed: FVC; FEV1; FEF25-75%; FEV1/FVC; RV; TLC; RV/TLC; intrathoracic gas volume; and specific airway resistance (sRaw). We used Poisson regression to investigate the following potential risk factors for severe impairment of pulmonary function: gender; age at first wheeze; age at diagnosis; family history of asthma; tobacco smoke exposure; length of hospital stay; and duration of mechanical ventilation.


RESULTS
The mean age was 13.5 years. There were pronounced decreases in FEV1 and FEF25-75%, as well as increases in RV and sRaw. These alterations are characteristic of obstructive airway disease. For the parameters that were the most affected, the mean values (percentage of predicted) were as follows: FEV1 = 45.9%; FEF25-75% = 21.5%; RV = 281.1%; RV/TLC = 236.2%; and sRaw = 665.3%. None of the potential risk factors studied showed a significant association with severely impaired pulmonary function.


CONCLUSIONS
The patients with PIBO had a common pattern of severe pulmonary function impairment, characterized by marked airway obstruction and pronounced increases in RV and sRaw. The combination of spirometric and plethysmographic measurements can be more useful for assessing functional damage, as well as in the follow-up of these patients, than are either of these techniques used in isolation. Known risk factors for respiratory diseases do not seem to be associated with severely impaired pulmonary function in PIBO.
Mattiello
Rita
R
Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil. rimattiello@hotmail.com
Mallol
Javier
J
Fischer
Gilberto Bueno
GB
Mocelin
Helena Teresinha
HT
Rueda
Belkys
B
Sarria
Edgar Enrique
EE
D000293:Adolescent; D000403:Airway Resistance / Q000502:physiology; D001989:Bronchiolitis Obliterans / Q000150:complications / Q000503:physiopathology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D010991:Plethysmography; D016012:Poisson Distribution; D012307:Risk Factors; D013147:Spirometry