The FDA is evaluating the risk of Medtronic (NYSE:MDT) silicone-based electromyogram (EMG) endotracheal tubes following reports of deaths and serious adverse events.

The FDA issued the warning last week in a letter to healthcare providers concerning the Medtronic NIM Standard Reinforced EMG Endotracheal Tubes and Medtronic NIM Contact Reinforced EMG Endotracheal Tubes. They are the only silicone-based EMG tubes currently sold in the U.S.

The FDA said there is a risk of airway obstruction, ventilation failure, oxygen deprivation and death from the 510(k)-cleared tubes, which provide an airway during surgery and use electrodes to monitor nerves to the laryngeal musculature when connected to an EMG monitor.

The FDA said the root cause and incidence rate are not known, and that it has not received similar reports for EMG tubes made from polyvinyl chloride (PVC). The agency is working with Fridley, Minnesota-based Medtronic “to further evaluate the issue and identify potential contributing factors and mitigation strategies.”

“Following the instructions provided in the device labeling can reduce the risk of airway obstruction,” the FDA said. “Providers should be prepared to emergently manage airway obstruction and ventilation failure if it occurs during surgery by reestablishing a safe airway, and reintubate if needed with a new tube that is not a silicone-based EMG endotracheal tube. The FDA will continue to work with the manufacturer to ensure that health care providers are aware of the potential risk of airway obstruction and ventilation failure.”