Hamilton Medical said certain lots of coaxial breathing circuit sets used with its Hamilton-C1, Hamilton T-1 and Hamilton-MR-1 ventilators are preassembled with an expiratory valve set that doesn’t perform as intended.
“In some cases, the expiratory valve membrane adhered to the sealing ring on the body of the expiratory valve, impairing valve opening and expiratory gas flow,” the company said in the recall. “The issue is not detected during the pre-operative test of the ventilator unless a test lung is actively ventilated.”
If the expiratory valve is stuck to the sealing ring, the malfunction appears within the patient’s first breaths after ventilation.
When expiratory gas flow is impeded, end-expiratory pressure rises or end-expiratory flow drops, triggering the ventilator’s “Exhalation Obstructed” alarm. The obstruction of expiratory flow causes inadequate ventilation and impaired gas exchange, which may result in poor ventilation and oxygen desaturation (hypoxemia), the recall said.
Related: BD recalls vascular access system needles after 4 patient deaths
A Class I recall is the most serious type of FDA recall, in which use of the device without correction may cause serious injuries or death. As of July 2, 2026, Hamilton Medical has reported four serious injuries and no deaths associated with the issue.
Hamilton Medical sent a letter to customers in May recommending that the breathing circuit sets be removed from where they’re used or sold.
MassDevice reached out to Hamilton Medical for comment and did not receive a response by the time of publication. We will update the story as necessary.
