BOS Predispose Factors
Anatomical and physiological factors in young children
:
• the relative narrowness of the respiratory tract
• hyperplasia of glandular tissue
• rich vascularization of the mucous
• predominantly
viscous mucus secretion
• low collateral ventilation
• insufficient local immunity
• relative weakness of the diaphragm
Factors of premorbid background:
• coupled allergic history
• a genetic predisposition to atopy
• perinatal pathology
• bronchial hyperreactivity
• rickets
• malnutrition
• early formula feeding
• respiratory
diseases
Environmental Factors:
• unfavorable environmental conditions
• passive smoking
• smoke inhalation promotes disruption of mucociliary clearance, causes
hypertrophy of bronchial mucous glands, destruction of bronchial
epithelium, reduces phagocytic activity
of macrophages, reduces the
activity of T- lymphocytes, stimulates IgE synthesis, increases the activity
of
the vagus nerve
• in children with alcohol fetopathy atopy develops, mucociliary clearance is
broken, protective immunological reactions are slowed.
Etiology of BOS
• Acute stenosing laryngotracheobronchitis of viral, bacterial
and viral etiology of diphtheria.
• Peritonsillar abscess, retropharyngeal abscess, epiglotit,
congenital stridor, hypertrophy of the tonsils and adenoids,
cysts, hemangioma and papillomatosis of the larynx.
• In infants - aspiration
caused by swallowing disorders,
congenital abnormalities of the nasopharynx, chalasia and
achalasia of the esophagus, tracheobronchial fistulas,
gastroesophageal reflux disease.
• Malformations of trachea, bronchi, RDS, cystic fibrosis,
bronchopulmonary
dysplasia, immunodeficiency, intrauterine
infection.
• At the 2nd and 3rd year of life BOS occurs in children with
asthma, with foreign body aspiration,
during migration of
round helminths, in bronchiolitis obliterans, in patients with
congenital and hereditary diseases of the respiratory system, in
children
with CHD, proceeding with pulmonary hypertension.