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  5. What is a Heater-Cooler Device?
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  1. What is a Heater-Cooler Device?

Information for Patients

Heater-cooler devices are often necessary for use during surgery because circulating blood and organs must be maintained at specific temperatures.The benefits of temperature control during surgery outweigh the small risk of infection associated with water-based heater-cooler devices.

Frequently Asked Questions

  1. What type of bacteria is involved in infections with water-based heater-coolers?
    There is the potential for Nontuberculous Mycobacteria (NTM) to be present and grow inside the water-based heater-cooler device. NTM are commonly found in the environment, such as in water and soil. They are typically not harmful, but in rare cases may cause infections in some patients.
  2. How are water-based heater-cooler devices associated with infection?
    Heater-cooler devices are used during open-chest surgeries to warm or cool a patient. There is the potential for NTM to grow in a water tank in the heater-cooler units. It is important to note that the water in the heater-cooler unit does not come into contact with the patient’s blood or body fluids. However, we have found that contaminated water droplets from the tank may disperse bacteria into the air (aerosolize) as it escapes from the heater-cooler unit into the operating room environment. The aerosolized NTM may then find its way into the open-chest cavity or onto a sterile device to be implanted.
  3. What should I discuss with my doctor prior to open-chest surgery?
    Discuss the benefits and risks of your surgical procedure with your doctor. For most patients, the benefit of undergoing a surgical procedure recommended by their doctor outweighs the risk of infection. Talk to your doctor about your concerns with infection risks. Life-saving surgical procedures should not be delayed. Ask your doctor what to expect following your procedure and when to seek medical attention. Ask your doctor what measures are being taken to minimize your risk of infection.
  4. Are certain groups of patients at higher risk of NTM infection?
    NTM, including Mycobacterium chimaera (a specific type of NTM), appears to be causing infection more frequently in those patients who are having open-chest surgery and are also receiving an implanted device, such as a heart valve or a vascular graft.
  5. If I’ve been exposed to NTM during surgery, what are the chances that I have or will get infected?
    While rare, NTM infections can and do occur. Most often they appear in patients who have undergone open-chest surgery.
  6. What are the symptoms of NTM infections?
    Some NTM bacteria can grow rapidly, but most NTM species associated with water-based heater-cooler infections are slow-growing. Because these bacteria grow slowly, it can take several months to over a year for an infection to develop.
    Signs of a possible NTM infection may include:
    • fatigue
    • fever
    • pain 
    • redness, heat, or pus at the surgical site
    • muscle pain
    • joint pain
    • night sweats 
    • weight loss
    • abdominal pain
    • nausea 
    • vomiting
  7. What should I do if I am experiencing symptoms?
    Contact your health care provider if you are experiencing symptoms and inform them that you had open-chest surgery.

    Additionally, the Centers for Disease Control and Prevention has provided a sample letter for patients to take with them when they visit their health care provider.

  8. Can NTM infection be treated?
    NTM infections can be treated with combinations of specific antibiotics. Some patients who become infected may need prolonged treatment (from months to years). Additionally, although rare, some heart valve patients who develop NTM infections after having cardiac surgery may require additional surgery. If untreated, NTM infection could be potentially fatal.

  9. Can I become infected through contact with someone who is infected with NTM?
    No, NTM infection is not contagious. It is not spread from person to person.


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