Philips was aware of safety risks with the sound-abatement foam in many of its ventilators and knew that the foam was ill-equipped for that use several years before the company issued a formal safety warning to customers and began replacing the foam, newly unsealed court documents show.
Philips initiated the recall—which has since stretched to include more than 5 million ventilators, CPAP and BiPAP machines and other respiratory devices around the world—in June 2021, and soon after received the FDA’s Class I rating, indicating a high risk of injury or death.
At the core of the recall was the polyester-based, polyurethane foam used to muffle sound and vibrations from the machines. The foam was found in many instances to break down over time, potentially sending dangerous particles, debris and chemicals into the user’s airflow.
In a tally released at the end of last month, the FDA said it had received more than 21,000 medical device reports linked to the issue between April 2021 and April 2022, including 124 patient deaths.
Philips hinted at the oncoming recall several months ahead of time. In an earnings report published in April 2021, the company announced it was taking a provision of 250 million euros after identifying “a quality issue in a component that is used in certain sleep and respiratory care products” and beginning to take precautions against the issue.
But documents attached to an ongoing lawsuit that groups together more than 100 legal actions against Philips show that the company’s knowledge of the safety risks date back at least several years before it began alerting customers.
Among the documents are several email exchanges between Bob Marsh, a technical director at Polymer Technologies—a distributor of Philips’ sound-abatement foam—and Lee Lawler, then the technical director of the polyurethane foam division at William T. Burnett, the maker of the foam. In April 2018, Marsh forwarded to Lawler a message from Vincent Testa, a mechanical engineer at Philips, who was seeking information about what would cause the material to break down.
“Recently we’ve received a few complaints from our customers that the foam is disintegrating,” Testa wrote. “The material sheds and is pulled into the ventilator air path. As you can imagine, this is not a good situation for our users.”
While sending Testa’s note to Lawler, Marsh referenced another message from 2016 in which he hadn’t identified Philips by name but mentioned that one of Polymer’s customers had received reports in the fall of 2015 of the foam breaking down after five years of use.
In an email to Fierce Medtech, Steve Klink, head of Philips’ global press office and industry relations, said the timeline of Philips’ awareness of the issue “is not new news.”
“In prior years, there were limited complaints related to foam degradation, which were evaluated and addressed by Philips Respironics on a case-by-case basis,” Klink said. “When Philips’ executive committee became aware of the issue and its potential significance in early 2021, we took adequate actions leading to the voluntary recall notification in June 2021.”
In 2016 and 2018 emails between Marsh and Lawler, the Burnett rep repeatedly stated that a polyether foam would be more resilient than the polyester option in a warm, high-humidity environment—like the one created by respiratory devices.
“I would not be surprised if ester foam, continuously exposed to 40°C (104°F) at high humidity, would exhibit signs of hydrolysis in as short a time as a year,” Lawler wrote in 2016. Marsh said he would pass on the message to his then-unnamed customer.
In April 2018, while forwarding the message from the Philips engineer, Marsh noted that Philips had tested both polyester and polyether foams in high heat and humidity and confirmed that polyether indeed performed better.
In early May 2018, Marsh passed along another message from Testa asking about the feasibility of continuing to use the polyester foam in the high-heat and -humidity environment, but with a preset replacement schedule in place. Lawler advised against it, saying Burnett “would not recommend use of polyester foam in such an environment,” and noting again that polyether foam would hold up much better.
A few weeks later, while passing on another message from Testa—this one asking for more information about the makeup of the foam—Marsh told Lawler that Philips was “investigating alternatives to polyurethane foam (ester and ether).” Lawler testified in an affidavit this year that he ultimately didn’t reply to the latter request, citing the need to protect Burnett’s proprietary information.
Regardless, and despite Lawler’s recommendations and its own tests of alternative materials to the polyester foam, Philips continued to use the polyester foam. According to the June 2021 recall notice, it was still being used in devices manufactured as recently as April 22 of that year.
Lawler’s affidavit and the attached emails were unsealed as Burnett was dismissed (PDF) from the lawsuits against Philips this month, following Lawler’s claim that the safety issues couldn’t be attributed to faults in the foam—which was merely manufactured in bulk by Burnett and sold to distributors—but rather to improper use of the foam in the products of end users like Philips.
In the year since Philips began the formal recall of the devices, it has expanded to include about 5.2 million machines distributed around the globe that are eligible for repair or replacement. In his email, Philips’ Klink said the company has so far produced 2.5 million replacement devices and repair kits, almost half of which have been shipped to the U.S.
Even though that work is already underway, the FDA remains less than thrilled with the recall’s progress. In March, the agency issued an order forcing Philips to immediately notify all affected users of the issue, citing its “inadequate” efforts to do so until then. Not long after, at the beginning of May, the FDA said it was considering another order that would force Philips to speed up the process of repairing, replacing or refunding all affected machines.
In its proposal (PDF) for that order, the regulator said there was “sufficient evidence” for it to believe that the safety risks were solely caused by Philips’ failure to “exercise due care in the installation, maintenance, repair or use of the devices at issue,” and that “the recalled devices that Philips manufactured after November 2015 were not properly manufactured with reference to the state of the art as it existed at the time of the devices’ manufacture.”
Klink told Fierce Medtech that Philips apologizes for and regrets the “concern and inconvenience” caused by the 2021 recall notice.
“This is one of the largest field actions in the medical technology industry, and we take the remediation very seriously. We have established a dedicated team of 1,000 colleagues working under direct supervision of the executive committee,” Klink said. “We have taken a systematic approach to addressing the unknowns and expanding production capacity. In an average year, we produce and distribute around one million sleep devices. In the meantime, we have scaled up by more than a factor of three, but inevitably it still takes time to remediate over 5 million devices.”
As those efforts continue, Klink reminded users of affected devices to register them with the repair and replacement program on Philips’ recall website.