This recall involves correcting devices, and does not involve removing them from where they are used or sold. The FDA has identified this recall as the most serious type. This device may cause serious injury or death if you continue to use it without correction.

Affected Product

  • Product Names: NOxBOXi Nitric Oxide Delivery System
  • Unique Device Identifier (UDI): 05060541640009
  • Model: MOXBOXI (NBL Manufacturer), REQNOXBOXI (Linde)
  • Serial Numbers: All

What to Do  

Make sure all affected personnel are provided with the recommended troubleshooting actions provided by the firm.

On September 8, 2025, NOxBOX Ltd. sent all affected customers an Urgent Medical Device Correction letter recommending the following actions:

For customers

  • Ensure all affected personnel are provided with a copy of the recommendations included in the letter.
  • Customers in the U.S. should complete the form attached to the letter and return it to Linde Gas & Equipment.

For clinicians

  • Be aware of conditions with lower servo pressure that are more likely to lead to dose fluctuations, including when:
    • Total volumetric flow through the NOxFLOW sensor (used by the NOxBOXi device to determine volumetric flow) is less than the minimum device requirement of 0.5 liters per minute.
      • This can occur when Bunnell LifePulse servo pressure is low (as lower servo PSI results in lower gas flow).
    • Conventional ventilators and the Bunnell LifePulse ventilators are set to:
      • Low servo pressures, generally less than 3.0 pounds per square inch
      • A pressure difference (ΔP) greater than 5.0cm H2O
      • Breath per minute rates of 300 bpm.
    • The Bunnell LifePulse HFJV has not stabilized (it may be in the process of stabilizing) and the user initiates nitric oxide delivery to the patient.
  • If nitric oxide dose fluctuations occur, ensure:
    • The NOxBOXi device has been placed into high frequency jet ventilator (HFJV) mode.
    • The NOxBOXi system has been fully calibrated in the last 30 days and system test has passed within the last 7 days prior to use.
    • The Bunnell “Ready” symbol is illuminated on the Bunnell LifePulse HFJV, and Bunnell-monitored values are stable before setting the nitric oxide dose on the NOxBOXi system.
    • The alternative (additional one-way valve) patient kit is being utilized. More information is available in the NOxBOXi Technical Guide.
    • Connections are secure (e.g. water trap barrel), free from damage and in the correct orientation (particularly the NOxFLOW sensor).
    • All components, tubing, filters, and connections are free from excessive moisture, or rainout, and there are no occlusions or blockages.
    • Then: 
      • Disconnect the NOxFLOW sensor line connector completely from the head unit, then reconnect.
      • Seat the the NOxFLOW sensor line (smaller green and clear tubing) connector correctly and make sure it is in the correct orientation with the green line at top.
    • Replace the NOxFLOW sensor.
  • NOxBOX Ltd. is developing a new software version that will include a modification to the software to resolve this issue. Once the software version is released, NOxBOX Ltd. will contact customers to arrange for a software update.

Reason for Correction

NOxBOX Ltd., a subsidiary of Linde Gas & Equipment Inc., is correcting NOxBOXi Nitric Oxide Delivery System due to safety considerations associated with using this nitric oxide delivery system together with the Bunnell LifePulse High Frequency Jet Ventilator and potentially other conventional ventilators. Customers reported fluctuations in the monitored nitric oxide value (greater than ±20% of the set dose) when the NOxBOXi system is used with specific settings on the Bunnel LifePulse. This issue may cause an interruption to therapy, leading to a drop in blood oxygen levels (desaturation) or increased pressure in the artery that carries oxygen from the heart to the lungs (pulmonary artery).

The use of affected product may cause serious adverse health consequences, including a drop in blood oxygen levels (desaturation), increased artery pressure, and death.

As of August 28, 2025, NOxBOX Ltd. has reported three serious injuries and no deaths associated with this issue.

Device Use

The NOxBOXi Nitric Oxide Delivery System is intended for the delivery and monitoring of a constant concentration of nitric oxide as well as monitoring of nitrogen dioxide and oxygen in the inspiratory ventilator lines of a patient undergoing inhaled nitric oxide therapy.

Contact Information

Customers in the U.S. with questions about this recall should contact their local clinical educator or the NOxBOX Customer Excellence Center at 1-833-NOX-VENT (669-8368) or LG.US.NOXIVENT@Linde.com.

Additional FDA Resources

Unique Device Identifier (UDI)

The unique device identifier (UDI) helps identify individual medical devices sold in the United States from manufacturing through distribution to patient use. The UDI allows for more accurate reporting, reviewing, and analyzing of adverse event reports so that devices can be identified, and problems potentially corrected more quickly.

How do I report a problem?

Health care professionals and consumers may report adverse reactions or quality problems they experienced using these devices to MedWatch: The FDA Safety Information and Adverse Event Reporting Program.