NOxBox, a Linde Company, has issued a letter notifying affected customers that certain nitric oxide delivery systems have updated use instructions, according to an FDA early alert.

The NOxBoxi Nitric Oxide Delivery System is intended for the delivery and monitoring of a constant concentration of nitric oxide and the monitoring of nitrogen dioxide and oxygen in the inspiratory breathing circuit of a patient undergoing inhaled nitric oxide therapy. The NOxMixer module is intended to deliver a continuous flow of nitric oxide, mixed in line with oxygen for emergency applications and when manually ventilating a patient.

NOxBox reported complaints of oxygen leaks due to failure of the oxygen tubing or tubing connection within the NOxMixer module of the NOxBoxi device, according to the FDA.

In some cases, oxygen leaks could result in increased dosage of nitric oxide or interruption in therapy, the FDA reports. Potential health consequences for an interruption during therapy include oxygen desaturation and increased pulmonary artery pressure with the associated complications.

According to the FDA, increased nitric oxide dosages may lead to methemoglobinemia and its associated complications. Neonates with congenital heart disease are at greater risk than other patients for health complications.

As of August 12, NOxBox has not reported any serious injuries or deaths associated with this issue, the FDA reports.

Affected Devices

FDA Recommendations

These devices are used in critical and emergency situations. Users should review and follow the updated instructions for pre-use inspection. Confirm that the NOxBoxi device functions correctly during its pre-use system checks prior to continued use.

On August 19, NOxBox sent all affected customers a letter recommending the following actions:

  • NOxBoxi devices affected by this issue do not need to be removed from service unless the device does not pass the pre-use system checks and setup checks as noted below.
    • To avoid leaks at the oxygen inlet of the NOxMixer, ensure the connection between the oxygen supply tubing and the NOxMixer is secure and tight-fitting.
    • Complete all NOxBoxi pre-use system checks. Ensure the device functions properly in Emergency or Manual Bagging modes, as described in Chapter 8 of the Technical Guide.
    • Check the flowmeter to ensure that the flow indicator ball rises appropriately to an increase in the oxygen flow setting on the NOxMixer control knob.
    • Ensure that at least one back-up device is available to allow for quick transition of devices if an oxygen leak is detected within the NOxMixer module of the NOxBoxi device.
  • Ensure all personnel using the device are provided with a copy of these recommendations and post the firm’s notice near the device.

See full information and updates at the FDA website.