The woes of Philips’ subsidiary Philips Respironics are not over, it seems, with new issues affecting some of the repaired devices after the company’s replacement programme for 5.5m faulty breathing machines in last year’s recall, mainly due to potential health risks from polyester-based polyurethane (PE-PUR) sound abatement foam.
In mid-November, the FDA issued an update to the recall affecting certain continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) machines and mechanical ventilators, after Philips told the agency that the reworded Trilogy ventilators now have two new potential issues.
First, the silicone sound abatement foam installed in the devices to replace the PE-PUR foam has the potential to separate from plastic backing and could possibly block the air inlet, lowering inspiratory pressure. If the air pressure is significantly impacted, the device could issue a low inspiratory pressure alarm.
Furthermore, trace amounts of particulate matter were found in the air pathway of some of the reworked ventilators. Preliminary lab results identified PE-PUR and environmental debris in some samples, and only environmental debris in others.
For Philips, the new issues mark a setback for its ongoing repair efforts. As Philips Respironics investigates the issues, it has temporarily suspended the repair of Trilogy 100/200 devices.
A Philips spokesperson told MedPage Today: “It is important to note that this only affects Trilogy 100/200 ventilators (approximately 3% of the registered affected devices globally), which have already been repaired. These problems do not affect any of the CPAP or BiPAP sleep apnea devices that have been remediated.”
The company said the repair of Trilogy 100/200 ventilators had begun in recent months, and that the two problems were detected with the corrected ventilators “after a limited number of complaints from the US and Japan”.
On the issue of silicone foam separation, Philips said that, as of 1 November, the observed occurrence rate of reportable events was less than 0.015% of corrected Trilogy 100 devices. The root cause was linked to an assembly step in inserting the silicone foam.
Additionally, pending an investigation into both of the new issues, Philips Respironics plans to take appropriate action if required.
Regarding the CPAP and BiPAP machines included in the June 2021 recall, Philips said they comprise 95% of the affected devices, and the repair and replacement of those devices is “well under way globally”.
The spokesperson told MedPage Today that “more than 4m replacement devices and repair kits have been produced, of which approximately 2m have been shipped to the US”.
Last week, the FDA issued another update that included information on medical device reports (MDRs) received from 1 August to 31 October 31 reportedly associated with the breakdown or suspected breakdown of PE-PUR foam used in the breathing devices included in the recall.
During the most recent period, there were more than 21 000 MDRs received, including 91 reports of deaths.
FDA recall 22 November (Open access)
See more from MedicalBrief archives:
Massive Philips recall highlights flaws in medical device surveillance
Philips recalls 5.5m sleep apnea machines and ventilators in US
Global ventilator safety alert from Philips after one patient dies, four injured