CPAP filters have been proposed by clinicians and patients as an interim fix to resolve some of the dangers associated with the foam at the center of the Philips CPAP/bilevel/ventilator recall. But new supplemental information released by Philips strongly advises against using bacteria filters for this purpose.

Philips states: “Philips does not recommend using bacteria filters outside of their normal intended use. Therefore, these bacteria filters should not be used on CPAP/BiLevel devices as a means of mitigating risk of PE-PUR foam chemical
emission or particulate matter for the following reasons:

  • Bacteria filters do not provide protection from the chemical emissions resulting from manufacturing or continued foam degradation. Furthermore, possible gas emission of the degraded foam has not been fully characterized yet throughout the life of the CPAP/BiLevel device.
  • In-line bacteria filters are not intended to be used under the current affected CPAP/BiLevel devices use cases.
  • Federal law (USA) restricts bacterial filters for sale under the order of a physician.
  • In-line bacteria filters are specified to be used where they can be monitored by a medical professional.
  • Bacteria filters need to be replaced frequently as referenced in the bacteria filter manuals, or as deemed necessary upon inspection by a medical professional.
  • Bacteria filters increase the resistance to airflow and will impact device performance of CPAP/BiLevel devices. Filters alter device performance by negatively impacting the maximum airflow, dynamic pressure and static pressure delivered by the CPAP/BiLevel devices. The extent of performance degradation will vary dependent upon prescribed therapy settings and air leakage which are different for each patient. Because of this, device performance may not meet the approved device’s specifications.
  • When an inline bacteria filter is used with a CPAP/BiLevel device the pressure reported by the device may be different than the prescribed pressure as well as the pressure received by the patient.
  • Certain circuits are unable to be used with bacteria filters due to an increased airway resistance that can affect device performance: 12mm circuit or heated humidifier circuit.
  • Bacteria filters may alter algorithms that govern therapy on many CPAP/BiLevel devices. Different modes (AutoCPAP, ASV, AVAPS, AVAPS-AE, Flex) require airflow sensing and demonstrate varying degrees of performance impact. Individual patients may experience varying degrees of performance impact.
  • Therapy device performance reporting in Care Orchestrator may be impacted. There may be an impact on event detection, and the prescribed pressure may not accurately reflect the pressure received by the patient.
  • Use of humidification, common to CPAP/BiLevel devices, will negatively impact the bacterial filter performance.
  • Fixed mode humidification cannot be used with bacteria filters as the humidification may increase condensation within the filter.
  • In-line bacteria filters specifications vary by manufacturer and the filters should be with accordance with the manufacturer’s labeling.”

Philips does note that bacteria filters are a part of the normal use of its Trilogy ventilators. “As indicated by the intended use of the bacteria filters for affected mechanical ventilator devices, exposure to particulates may be partially mitigated using a bacteria filter. However, please note that the use of the bacteria filter will not mitigate the harm of the chemical emissions.”

Illustration 157731844 © Eugeny Kaminskiy |