FDA Issues Safety Information About Heater-Cooler Devices

Heater-Cooler Devices



The U.S. Food and Drug Administration (FDA) published safety information to heighten awareness about infections associated with heater-cooler devices used during open-chest cardiac surgical procedures that utilize an extracorporeal bypass circuit. There is the potential for nontuberculous mycobacteria (NTM) organisms to grow in the water tanks of the heater-cooler device. While the water in the heater-cooler device is not intended to come into direct contact with the patient, if water within the heater-cooler tanks is contaminated with NTM, there is the potential for it to become aerosolized into the operating room and enter the sterile field (e.g., open-chest cavity and/or a sterile implant). NTM infections may cause serious illness or death. NTM infections are difficult to detect because patients infected may not develop signs and symptoms of infection for months to years after initial exposure. For more information about FDA’s understanding of the issue and recommendations to reduce risk of infection to patients, please visit: The FDA’s Web page on heater-cooler devices.

Heater-Cooler Devices

Heater-cooler devices are often necessary for use during surgeries to warm or cool patients as part of their care. They are especially important tools for surgeries involving the heart, lungs, esophagus, and other chest organs (cardiothoracic surgeries). Heater-cooler devices, as shown below in Figure 11, include tanks that provide temperature-controlled water to external heat exchangers or to warming/cooling blankets through closed water circuits.

Figure 1: Schematic representation of heater–cooler circuits tested for transmission of Mycobacterium chimaeraduring cardiac surgery despite an ultraclean air ventilation system. Blue arrows indicate cold water flow, and red arrows indicate hot water flow and patient blood flow.

As indicated above in Figure 1, the:

• Blue arrows identify the cardioplegia circuit and shows cardioplegia solution entering the “heart lung machine.” Cardioplegia is used to stop the heart during surgery.
• Rectangles with zigzag lines are heat exchange coils. They separate heater-cooler fluid flow from patient fluid or blood flow.
• Red arrows identify the patient blood circuit and shows hot water flow and patient blood flow.

Additionally, the water in the heater-cooler device is isolated from the patient, cardioplegia solution and blood circuits.

Heater-cooler devices are Class II devices that can be cleared under one of the following cardiovascular classification regulations:

• 870.4250 Cardiopulmonary Bypass (CPB) Temperature Controller
• 870.5900 Thermal Regulating System

The CPB Temperature Controller is intended to supply temperature-controlled water to heat exchangers associated with devices (e.g., oxygenator) intended to keep circulating blood and organs at a specific temperature best suited to the type of surgery being performed. Thermal Regulating Systems are generally cleared for use with warming/cooling blankets. Although heater-cooler devices fall under the cardiovascular classification regulations, they may be used during a variety of medical procedures.

This website contains information for patients, the FDA’s recommendations for health care providers and health facilities that use these devices and steps the FDA is taking to help minimize the risk of infections associated with these devices.

1 Sommerstein R, Rüegg C, Kohler P, Bloemberg G, Kuster SP, Sax H. Transmission of Mycobacterium chimaera from heater–cooler units during cardiac surgery despite an ultraclean air ventilation system. Emerg Infect Dis. 2016 Jun http://wwwnc.cdc.gov/eid/article/22/6/16-0045_article