Asthma Nebulisers | Inhalation devices for Acute Asthma

What are Nebulizers

Nebulisers are inhalation devices specially used in individuals with acute asthma. Nebulisers deliver the drug directly to the lungs and cause instant relief and can be used at any age. They should produce a particle size of 2.5 microns or less.
Normally nebuliser is driven by an air compressor (nebulisation machine or automiser) but in acute cases of asthma it can be driven by oxygen so that it provides both beta-2-adrenergics and oxygen.

Their main role is in delivery of beta-2-adrenergics and ipratropium to patients with acute asthma.

Types of Asthma medicines in Nebulisers

Medicines available to be used as nebulisers are salbutamol, ipratropium and budesonide. These medicines are available in the form of respules.

1. Salbutamol

Is a specific beta-2-adrenergic agonist. Its primary action is to stimulate adenlycyclase which catalyses the formation of cyclic AMP.
The cyclic AMP thus formed mediates smooth muscle relaxation and broncho-dilation.
These are generally safe, produce quick result and the relief lasts for 3-8hrs.
In acute asthma, salbutamol is nebulised in dose of 0.002ml/kg/dose in 3ml of saline. It may be given over 10 minutes after every 4 to 6 hours.
It is available in the market as asthalin respirator solution.
Beta-2-adrenergics may show tachyphylaxis i.e. diminished response if the treatment is very prolonged.

2. Ipratropium bromide

Recently use of anti-cholinergic or atropine like compounds such as ipratropium are used successfully in acute asthma.
These are more effective when used in combination with beta-agonists.
Ipratropium is usually not used in long term management of asthma.
When administered by inhalation route, the anti-muscarine action of ipratropium is restricted to the lungs.
Ipratropium can reverse broncho-spasm following histamine and allergens, exercise and cold induced broncho-spasm is also reversed.
It has no effect on the visco-elastic properties of mucous and does not affect muco-ciliary function.
It is available as ipravent respules. In acute asthma ipratropium is added to nebulised beta-agonist in dose of 0.25mg.

3. Budesonide

It is a corticosteroid which is available for use of nebulisation and locally exerts an anti-inflammatory and immuno-suppressive action in bronchial tree.
It inhibits release of mediators such as histamine and cytokines etc.
It reverses the marked increase in eosinophils in mucosa.
Budesonide is usually not used in severe acute asthma.
Available in as budecort respules. 0.25mg/ml to be added to beta-agonists for nebilisation.

July 2, 2009 | Filed Under Respiratory & Lung Diseases

Comments

Leave a Reply