More than a year into the repair-and-replace program for the 5.5 million CPAP and BiPAP machines and other ventilators recalled by Philips since June 2021, the Dutch devicemaker has identified a pair of potential issues in some of the refurbished devices.
Philips has paused the repair efforts for affected Trilogy 100 and 200 series ventilators, it announced earlier this month. The company said it has received “a limited number of complaints” related to remediated machines, which are now under investigation.
With the investigation and shipping hold, Philips said it will take several weeks longer than anticipated to return repaired Trilogy ventilators to patients, who were previously given a timeline of four to six weeks. However, Philips asked users to continue sending in their unused Trilogy machines for repairs, so as to avoid further delays in the repair-and-replace program.
According to Reuters, a Philips spokesperson said the Trilogy 100 and 200 series ventilators represent only around 3% of the recall, which comes out to about 165,000 devices. Though the overall repair-and-replace program for Philips’ recall kicked off in September 2021, repairs for the affected Trilogy machines didn’t begin until June of this year, when the company estimated that the full remediation process would take 12 to 14 months to complete.
In an update of its own last week, the FDA provided more details about the new safety issues with the already-replaced devices.
The first of the two identified issues relates to the new silicone-based foam installed in the ventilators to replace the original polyester-based polyurethane (PE-PUR) foam used to muffle sound and vibrations. The entire recall stemmed from the discovery that the PE-PUR foam could break down over time, releasing potentially dangerous particles and chemicals into a user’s airflow.
Though the new foam is meant to avoid that erosion, Philips reported to the FDA that the silicone version may separate from its plastic backing within the machines. If that happens, it could block the inflow of air, causing the inspiratory pressure to drop lower than is required to keep a user breathing normally—and therefore setting off a low pressure alarm.
Other complaints to Philips resulted in the discovery of “trace amounts of particulate matter” in the air pathways of some of the refurbished Trilogy devices. Per the FDA, while some samples were found to include only environmental debris, others showed residual particles from the PE-PUR foam.
The agency said it has requested more information from Philips “to better understand the cause of the issues and to provide informed recommendations to patients, caregivers and healthcare professionals.”
This isn’t the FDA’s first investigation into the replacement materials. Almost exactly a year ago, the regulator issued a statement detailing another potential issue with the new silicone-based foam.
When installed in one of the recalled devices—a respiratory support machine available only outside the U.S.—the foam was found to have failed a safety test related to the release of volatile organic compounds. However, the foam achieved “acceptable” results when tested in devices cleared in the U.S.
The FDA didn’t recommend that patients who had already received the refurbished devices stop using them, but asked Philips to tap an independent laboratory to perform additional safety tests of the new sound abatement foam. Neither Philips nor the FDA has since provided an update about the progress or findings of those tests.