ABSTRACT
Introduction: Continuous positive airway pressure (CPAP) is an aerosol-generating procedure with increased potential to transmit COVID-19 during use. Our health service was located at the epicentre of the COVID-19 outbreak in Melbourne, Australia, placing our patients and staff at high risk of nosocomial COVID-19 infection. We describe our experience with a modified CPAP circuit utilising non vented masks and high efficiency microbial filters to reduce viral transmission in patients potentially infected with COVID-19. Method(s): Retrospective analysis of medical records and polysomnography (PSG) reports of 82 inpatients who used CPAP during admission, and 72 patients who underwent CPAP in-lab PSG with our modified circuit. This consisted of a non vented mask, 2 high efficiency microbial filters, an oxygen port (placed distal to a filter) for expiration, and ancillary equipment such as disposable tubing. Result(s): The mean age amongst inpatients (45 males/37 females) was 65.9 +/- 11.6 years. Equipment issues occurred in 28/82 patients. 9 patients (10.9%) chose not to use PAP therapy, 10 patients (12.2%) experienced excessive mask leak and 6 patients (7.3%) experienced discomfort. 7 patients (8.5%) were discharged before the circuit could be unmodified. The majority of issues occurred on non-respiratory wards. The mean age of in-lab PSG patients (48 males/24 females) was 51.3 +/- 13.6 years. 24 CPAP implementation, 31 CPAP treatment review and 17 split-night studies were included. Circuit modification did not impact the study conclusion in the majority (97.2%). Mask leak (13.9%) and patient discomfort (8.3%) were common. Conclusion(s): Our modified circuit was safe and well tolerated in the majority and did not significantly affect the outcome of in-lab CPAP studies.