Most respiratory conditions are treated with an inhaled drug. This enables the drug to effectively target the receptors in the lungs.
Although the nebulising unit of air compressor, mask, chanmber and tubing is commonly referred to as the nebuliser, it’s actually the small contraption attached to the mask which contains the fluid which is the nebuliser. It is this that transforms the liquid drug into fine aerosol. In many cases, inhalers employed with spacers and the proper technique are as effective, or more effective as nebulisers. This may be because of the inefficiency of the method with around 12% of the drug actually reaching the target receptors. This depends on the patients’ breathing rate and depth, the health and age of the patients’ lungs, the volume of the drug being administered and the type of nebuliser chamber. The nebuliser chamber, its components, and air flow rate, determine the size of droplets produced. If the droplet size is too small, the drug will end up in the peripheries of the lungs which decreases the efficacy of the drug. Overfilling the chamber will also affect efficacy as well as prolonging the time taken to administer; this should be 5-10 minutes. Once the nebuliser has finished there is likely to be a small residue of the drug in the chamber.
Nebulisers are not generally indicated for mild-moderate asthma because it has been shown that this can often lead to an overuse of bronchodilators rather than preventers.
Nebulisers are used to administer anticholinergics, corticosteroids, bronchodilators, antifungals and antibiotics as well as recombinant human deoxyribonuclease (used to increase expectoration and reduce viscosity in cystic fibrosis patients). If the nebuliser is used with antibiotics or corticosteroids a mouthpiece should be used to avoid contact with the skin and eyes.
Generally nebulisers are no more efficient than inhalers, and in fact some inhaled drugs are not available in nebuliser form, they can promote over-dependence on bronchodilators in asthmatics and also be habit-forming if the patient enjoys the cooling sensation. It is, however, helpful for patients with reduced manual dexterity or patients receiving palliative care.