So that the fog lifts

The use of nebulizers is part of the everyday treatment of cystic fibrosis for both mucociliary clearance and chronic infection therapy. With regard to devices, the focus is often on correct application, but a no less important aspect is often neglected: proper hygiene. The instructions are usually limited to following the manufacturer’s instructions. However, these are often vague and easily lead to confusion for the user.

Jane Bell of the Northern Ireland Paediatric Cystic Fibrosis Centre, Dept of Physiotherapy, Royal Belfast Hospital for Sick Children, Belfast, and colleagues therefore point to the need for an evidence-based universal guideline on the care and hygiene of nebulizers for both home and inpatient use [1]. They reviewed the scientific literature to propose an evidence-based approach to nebulizer hygiene that helps ensure optimal drug delivery and infection prevention and control.

Mesh nebulizer in need of special care

Nebulizer maintenance plays an important role in performance, especially for electronic nebulizers with vibrating mesh. Such nebulizers have a sieve with about 4000 identical holes (2-4 μm diameter), where there is a risk of clogging these holes if they are not cleaned regularly. While it is reported that patients are familiar with the importance of nebulizer care, the mesh component is often never cleaned, nor is an appropriate disinfection method chosen, which in turn has deleterious effects on the mesh. This may result in reduced nebulizer output, longer nebulization time, and premature nebulizer shutdown.

Microbial contamination threatens

Studies have shown that respiratory therapy devices can be contaminated by Gram-negative bacteria, and several outbreaks with fatal outcomes have been reported after contamination of disinfected nebulizers with Pseudomonas aeruginosa in patients with COPD. Maintenance, cleaning and disinfection of the nebulizer are therefore of great importance, as parts of the nebulizer, namely the compressor hose, the drug chamber, the T-piece and the mouthpiece, can be contaminated with both bacteria and fungi.

In this context, the diversity of bacteria and fungi found in CF sprays is large. A total of 35 bacterial genera were isolated: 24 genera of Gram-negative bacteria, 10 genera of Gram-positive bacteria, and the Gram-variable Paenibacillus. Of concern, the researchers report that CF patients’ devices were positive for the clinically significant Burkholderia cenocepacia, Stenotrophomonas maltophilia, and P. aeruginosa. Chronic colonization of P. aeruginosa contributes significantly to the deterioration of lung function in CF and is ultimately associated with disease morbidity and mortality. With respect to the diversity of yeasts and filamentous fungi contaminating CF nebulizers, two genera of yeasts and 14 genera of filamentous fungi were reported. Yeasts and molds were also reported in nebulizer parts of CF patients after washing and drying with high prevalence (57.7%). Contaminated nebulizers could potentially lead to the deposition of infectious agents that go beyond the level of ciliated epithelium into regions of the pulmonary airways distal to the terminal bronchioles and, as such, potentially cause pulmonary infection, the authors write.

Hygiene tips

In order to effectively prevent such contamination, the researchers make a series of recommendations to help ensure that nebulizers are cleaned and used hygienically in both home and inpatient settings.

First and foremost, this includes that healthcare professionals, cystic fibrosis patients or caregivers should wash their hands and use hand sanitizer gel before and after cleaning and disinfecting the nebulizer. Medical professionals should wear gloves, with hand hygiene performed after glove removal. New nebulizers and separate associated parts should be washed before first use and equally during inpatient admission and at home after each use. After inactivity of more than 24 hours, nebulizers should be washed and disinfected again immediately before use.

During an inpatient stay, it is not advisable to wash nebulizer parts directly in sinks, especially in bathrooms, according to the author team. This is especially important if nebulizer parts are not disinfected immediately after each use. In addition, nebulizers should not be washed in bathrooms with toilets due to the risk of airborne contamination of the nebulizer from contaminated toilet droplets during flushing. Instead, disposable bowls or basins for washing would be an option, which can be sterilized by the autoclave process (provided the nebulizer manufacturer states that the device can be safely autoclaved). Disinfection of nebulizer parts should be performed immediately after washing, and always in the patient’s room.

The same applies to the home environment: kitchen or wash basins are not recommended for cleaning the nebulizers. Neither does the dishwasher. Nebulizer parts should be cleaned in a special plastic, glass or metal bowl in the patient’s kitchen. Such shells need to wash and dry completely between each use.

Disconnect from the compressor unit before washing

Before washing or disinfecting, Bell et al. recommend separating the nebulizer from its compressor unit and disassembling it into its component parts. Normal tap water can be used, provided that disinfection is subsequently performed. If possible, the water should be warm or hot and comfortable for the user. If immediate disinfection is not possible, sterile water must be used for the final rinse. However, the nebulizer cannot then be considered disinfected in such cases. When cleaning, it is recommended to add some rinsing agent (according to the manufacturer’s instructions) to the warm tap water.

For stationary use, it is not recommended to recycle disposable trays. Nebulizer wastewater should not be disposed of through sinks or toilets to avoid cross-infection between users and subsequent patients. If metal trays are used for cleaning, they and the wastewater should be sent to the station’s airlock to dispose of the wastewater and sterilize the metal tray by autoclaving. For the cleaned nebulizers, the authors’ tip is to disinfect by heat exposure with an electric baby bottle steam disinfector according to the manufacturer’s instructions for both home and stationary use. After disinfection in a baby bottle steam disinfector, the nebulizer parts should remain undisturbed in the disinfector until the next use (within 24 hours). But if for some reason the lid is lifted off, the scientists recommend repeating the disinfection process.

Uniform line urgently needed

Using a nebulizer is only one aspect of the daily treatment burden for people with cystic fibrosis. As a result, nebulizer maintenance and hygiene can be easily overlooked as an essential part of everyday disease management. In addition to the importance of regular use, the importance of nebulizer hygiene should also be emphasized during patient education, as it is critical to preventing re-infection. Varying manufacturer recommendations, lack of guidelines, and conflicting statements and advice from caregivers can negatively impact adherence to nebulizer care. A uniform line would be urgently advised here, the authors write.

Take-Home Messages

Nebulizer hygiene is important to ensure optimal performance of the device and an important to avoid microbial contamination of the components and possible (re)infection for the user.
Current nebulizer hygiene practices are challenging both at home and during inpatient stays.
The location, timing and procedures for cleaning, disinfecting and drying nebulizer components must be considered.
Patient, family and staff education is important to ensure long-term compliance with nebulizer hygiene guidelines.

Literature: