Results: 51 patients with severe bronchiolitis include 29 boys, 22 girls, mean age 5, 3 months old, malnutrition 45%. Risk factors are preterm birth 25, 5%, neonatal respiratory failure 13, 7%, congenital heart disease 45%, HIV infections / AIDS 25, 5%, bronchopulmonary dysplasia 5, 9% and myasthenia 3, 9%.