The history, current state and perspectives of aerosol therapy

Nebulization is a very effective method of drug administration. This technique has been popular since ancient times when inhalation of plants rich in tropane alkaloids with spasmolytic and analgesic effects was widely used. Undoubtedly, the invention of anasthesia in the 19th century had an influence on the development of this technique. It resulted in the search for devices that facilitated anasthesia such as pulveriser or hydronium. From the second half of the 21st century, when the first DPI and MDI inhalers were launched, the constant development of aerosol therapy has been noticed. This is due to the fact that nebulization, compared with other means of medicinal substance application (such as oral and intravenous routes of administration), is safer and it exhibits a positive dose/efficacy ratio connected to the reduction of the dose. It enables drugs administration through the lung and possesses very fast onset action. Therefore, various drugs prescribed in respiratory diseases (such as corticosteroids, β-agonists, anticholinergics) are present on the market in a form of an aerosol.

Aerosol Release, Distribution and Prevention during Aerosol Therapy: A Simulated Model for Infection Control.

Background: Aerosol therapy is used to deliver medical therapeutics directly to the airways to treat respiratory illnesses. A potential side-effect of this form of treatment is the release of fugitive aerosols into the environment and the exposure of caregivers, other patients, and bystanders to potential viral infections. The aim of this work was to use both flow visualisation and aerosol particle characterisation techniques to study the dispersion, concentrations and size distributions of fugitive aerosols emitted during aerosol therapy delivered via a standard mouthpiece.Methods: Aerosol therapy was delivered via a nebuliser, aerosol holding chamber and mouthpiece to a spontaneously breathing adult patient model that could mimic the release of patient-derived bioaerosol. A combination of laser and Schlieren imaging were used to non-invasively visualise the release and dispersion of fugitive aerosol particles. Time varying aerosol particle number concentrations and size distributions were measured with optical particle sizers at clinically relevant positions. Results: The addition of a capture filter to the expiratory port of the mouthpiece significantly reduced the release and spread of fugitive aerosols. Capture filters were effective in curtailing the release of fugitive aerosols of respirable size, ≤ 5 µm in diameter (P ≤ 0.05). Conclusions: The findings suggest that, where possible, capture filters should be added to the expiratory ports of all aerosol therapy devices to prevent airborne transmission of respiratory illnesses and create safer conditions for healthcare workers and patients.

Pros and Cons of Nebulizer Treatment in Asthma Exacerbation During the COVID-19 Pandemic

ABSTRACT Nebulizers generate aerosols and may potentially transmit respiratory viral particles including SARS-CoV-2. There is a great concern about the use of a nebulizer in the treatment of asthma exacerbations in the hospital or home setting during the COVID-19 pandemic and its use is not recommended unless essential. However, aerosol therapy should not be avoided in obligatory indications. Therefore, indications of nebulizer use during the pandemic should be evaluated on an individual basis in case of a severe asthma attack, and infection control recommendations should be followed by clinicians while using nebulizers. In this article, we aimed to assess the safety in addition to the “pro” and “con” sides of nebulizer treatment in asthma exacerbation during the COVID-19 pandemic. Keywords: Asthma, coronavirus disease 2019, COVID-19, SARS-CoV-2, nebulizers