Hypertonic Saline as Add on Therapy in Preschool Children With Acute Wheezing Attack.

A randomized double blind, controlled, (DBCR) trial. To investigate the efficacy of adding inhaled Hypertonic Saline (HS) treatment for 1-6 year old children with asthmatic attack presenting to ED

Background:

Children under the age of 5 years have the highest hospitalization rate of asthma. The most common causes of acute exacerbations of asthma requiring urgent medical care are viral respiratory infections. Most of these children < 6 years old are not atopic.

These investigators have previously demonstrated in wheezy infants with acute viral bronchiolitis that nebulized hypertonic saline produces a clinical significant reduction in length of hospital stay and improves the clinical score and is considered an effective and safe treatment for infants with acute viral bronchiolitis (Cochrane 2008).

Hypertonic saline solution acts in the airways in several mechanisms:

It Stimulates ciliar beat via the release of prostaglandin E2 and increases mucociliary clearance.

It Breaks the ionic bonds within the mucus gel, thereby reducing the degree of cross linking and entanglements and lowering the viscosity and elasticity of the mucus secretion.

HS induces an osmotic flow of water into the mucus layer, re-hydrating secretions and improving mucus rheology.

HS reduces edema of the airway wall by absorbing water from the mucosa and submucosa.

HS can cause sputum induction and cough, which can help to clear the sputum outside of the bronchi and thus improve airway obstruction.

It is estimated that many of the above hypertonic saline responding elements may play a role in this viral induce wheezing such as: mucosal and submucosal edema, peribronchial infiltrate of inflammatory cells, necrosis and desquamation of ciliated epithelial cells, and excess mucus secretion. The combination of an airway wall swelling, sloughing of necrotic debris, increased mucus production and impaired secretion clearance, eventually contribute in addition to bronchospasm to airway obstruction, gas trapping, atelectasis and impaired gas exchange. Moreover, as postulated in "status asthmatic", the relative contribution of these "non-spasmodic" pathological and pathophysiological consequences of viral and asthmatic inflammation to airway obstruction, gas trapping, atelectasis and impaired gas exchange become even more important in these children already treated with maximum dilatation dose of bronchodilating drugs in the emergency department.

The above mentioned theoretical benefits provide the rationale for the possible treatment of viral induced acute wheezing ("asthma") attack with nebulized hypertonic saline solution in young pre-school children presenting to the Pediatric Emergency Unit with acute (mostly viral induced) wheezing.

Therefore, the purpose of the present study is to investigate the addition of frequently nebulized 5% HS/albuterol combination to standard therapy of acute asthmatic episodes presenting to the ED in preschool children in a prospective, randomized, double-blind, controlled fashion.