DNase treatment for atelectasis in infants with severe respiratory syncytial virus bronchiolitis

Respiratory insufficiency due to respiratory syncytial virus (RSV) bronchiolitis is partly due to the abundance of thickened mucus and the inability to clear it from the airways. Mucus in RSV bronchiolitis contains necrotic inflammatory and epithelial cells. The viscoelastic properties of purulent airway secretions are largely due to the presence of highly polymerized deoxyribonucleic acid (DNA). Recombinant human deoxyribonuclease (rhDNase) is known to liquefy such mucus in patients with cystic fibrosis, whereas case reports described a beneficial effect in other respiratory disorders. The authors hypothesized that rhDNase would diminish atelectasis and mucus plugging in infants with severe RSV bronchiolitis. Two infants with RSV bronchiolitis with massive unilateral atelectasis in whom mechanical ventilation was imminent due to exhaustion, and three mechanically ventilated infants (two neonates, one with bronchopulmonary dysplasia) with RSV bronchiolitis with pneumonia received treatment with 2.5 mg nebulized rhDNase twice daily. Following administration of nebulized recombinant human deoxyribonuclease, clinical and radiological parameters improved quickly. Mechanical ventilation could be avoided in two infants while in three infants on artificial ventilation, clinical recovery started following the first dose of the drug. A therapeutic trial of recombinant human deoxyribonuclease may be an option in the treatment for atelectasis in severe or complicated respiratory syncytial virus bronchiolitis in infancy.