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

Respiratory insufficiency due to respiratory syncytial virus (RSV) bronchio litis is partly due to the abundance of thickened mucus and the inability t o clear it from the airways. Mucus in RSV bronchiolitis contains necrotic i nflammatory and epithelial cells. The viscoelastic properties of purulent a irway secretions are largely due to the presence of highly polymerized deox yribonucleic acid (DNA). Recombinant human deoxyribonuclease (rhDNase) is k nown to liquefy such mucus in patients with cystic fibrosis, whereas case r eports described a beneficial effect in other respiratory disorders. The au thors hypothesized that rhDNase would diminish atelectasis and mucus pluggi ng in infants with severe RSV bronchiolitis. Two infants with RSV bronchiolitis with massive unilateral atelectasis in w hom mechanical ventilation was imminent due to exhaustion, and three mechan ically ventilated infants (two neonates, one with bronchopulmonary dysplasi a) with RSV bronchiolitis with pneumonia received treatment with 2.5 mg neb ulized rhDNase twice daily. Following administration of nebulized recombinant human deoxyribonuclease, clinical and radiological parameters improved quickly. Mechanical ventilati on could be avoided in two infants while in three infants on artificial ven tilation, 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 syncy tial virus bronchiolitis in infancy.