Historically, there has been limited reuse of positive airway pressure (PAP) devices, including both continuous positive airway pressure (CPAP) and non-invasive ventilation (NIV) devices, within NSW health loan pools and equipment allocation programs for home use.
The question of bacterial contamination in these machines has, to date, not been addressed in a scientifically rigorous way. There is no convincing population research to suggest there is an increased risk of harm caused by infections attributed to PAP device use. Concerns over the potential contamination of these PAP devices and a lack of evidence-based cleaning procedures are key barriers to re-allocating returned devices to new patients.
This project investigated the presence of bacteria in air samples taken from PAP devices to develop an evidence base to support the re-purposing of equipment and guideline development.
No bacteria recovered from air samples
This was a benchtop proof of concept study in which the project team deliberately inoculated bacteria into the airflow pathway of PAP devices to develop and validate a collection methodology for pressurised air samples. The team used the intentional contamination of various parts of a PAP device to determine the survivability of bacteria in airflow, when simulated to represent contamination from the environment, water source/humidifier or patient (mask contamination and their exhaled air). The project team recruited a sample of real-world devices to determine if air sample contamination was present before and after cleaning.
The project team recovered no bacteria from experimental air samples from PAP devices, under normal use conditions, even with the gentlest possible flow and highest feasible concentration of experimental bacteria (hundreds of trillions of cells). Ongoing testing of real-world devices is following this pattern of behaviour. This means that the risk of transmission of viable bacteria in air flow is very low. Additionally, surface swabs demonstrated that current cleaning procedures were sufficient for removing any organisms of concern from the external surfaces.
This is an important, world first observation of the non-viability of bacteria from PAP device airflow under contamination conditions. This challenges infection transmission as a valid barrier to equipment re-use and supports the implementation of the Enable NSW Going Circular Project. However, some special populations, such as immunocompromised people, may require further consideration.
