Nebulized N-Acetyl CysteineNebulized N-Acetyl Cysteine for Bronchiolitis in Inpatient Hospital Use

Bronchiolitis is the major cause of hospital admission in infants < 6 months of age and usually viruses like Respiratory syncytial virus (RSV), human metapneumo virus, Adeno virus, para-influenza virus, Rhino virus and influenza virus are the main culprit. In the US, acute bronchiolitis in infancy is responsible for approximately 150,000 hospitalizations yearly at an estimated cost of $500 million. Globally in 2005 it was estimated that at least 33.8 million were affected with RSV and in the same year, RSV associated severe acute lower respiratory infection (ALRI) were responsible for \~3.4 million hospitalizations and 66,000-199,000 deaths worldwide, with 99% of these deaths in developing countries.

In acute bronchiolitis there is cellular swelling and excessive mucus production. There is also proliferation of goblet cells, which leads to increased mucus production. The excess mucus produced is poorly cleared by non-ciliated (regenerating) epithelial cells leading to areas of narrowing and blocking of the bronchioles, causing the airway obstruction, hyperinflation, increased airway resistance, atelectasis and increased ventilation-perfusion mismatch that characterize acute bronchiolitis.

Currently there is no medicine that has proven effective in treating acute bronchiolitis and per American Academy of Pediatrics guidelines the management of acute bronchiolitis remains supportive care for the acute respiratory failure associated with acute bronchiolitis.

N-Acetyl Cysteine (NAC) is an antioxidant, anti-mucus compound that increases intracellular glutathione at the cellular level. It cleaves disulfide bonds by converting them to two sulfhydryl groups. This action results in the breakup of mucoproteins in lung mucus, reducing their chain lengths and thinning the mucus. Nebulized NAC is not studied well in acute bronchiolitis and is uncommonly used for the same. NAC has been studied in the treatment of various disease states, including those pulmonary in nature such as cystic fibrosis, chronic bronchitis, non-cystic fibrosis bronchiectasis and found to be beneficial.

With this background knowledge, the purpose of this study is to evaluate the effectiveness of nebulized mucolytic therapy in treatment of children with viral bronchiolitis.