Air sampling from PAP devices: Gone with the wind?
Year: 2024
Type: conference-abstract
Abstract: Introduction: The infection risk posed by airflow from Positive Airway Pressure (PAP) devices is unclear, with rare cases of reported harm. Currently, no validated air sampling methodology for PAP devices exist. Aims: To develop an air sampling methodology for PAP devices to identify a threshold of detection to determine sensitivity of the collection rig and to assess specific inoculation sites representing potential contamination using culture and molecular methods. Methods: Andersen cascade impactor was compared with broth-based collection with consideration of time (1-60min), pressure (4 and 20cmH2O) and tube length (5-200cm) to determine peak collection efficiency. Secondly, a dilution series using nebulised Pseudomonas Aeruginosa (PA) and Escherichia Coli (EC) was used to find the limit of detection. Triplicate samples were collected in broth and grown on agar. PCR analysis was performed in the absence of growth with 16sRNA sequencing. Thirdly, PA inoculation was performed at the PAP air inlet, air outlet, humidifier chamber and tubing. Results: Viable cultures were only obtained when the organism was nebulised into the PAP circuit, above concentrations of 1.5x10^8 CFU/mL for EC and 1.5x10^6 CFU/mL for PA. There were no viable cultures from air sampling of the PAP device inoculated with organisms and used under normal operating conditions. PCR was positive with humidifier and tubing inoculation. Sequencing determined that the target organism was detected. Conclusion: An air sampling methodology for PAP devices was validated using limit of detection. Viable cultures were not obtained under usual PAP operating conditions despite inoculation, however, positive PCR suggests airflow from the PAP device may affect organism viability.
Source: Sleep Science
Authors: Olivia McGuiness, Sebastiaan Van Hal, Collette Menadue, Susy Mathew, Rania Salama, Amanda Piper, Sheila Sivam
Institutions: Royal Prince Alfred Hospital, Macquarie University
Language: English
Topic: Nosocomial Infections in ICU
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4404096822