Heater-cooler devices and nontuberculous mycobacterium
November 2016
Saint Luke’s Hospital of Kansas City
Heater-cooler devices and nontuberculous mycobacterium
Heater-cooler devices are used in certain heart, lung, and liver surgeries to help regulate blood temperature. The Stockert 3T heater-cooler, manufactured by LivaNova PLC (formerly Sorin Group Deutschland), is the most commonly used heater-cooler model in hospitals throughout the United States, including Saint Luke’s Hospital of Kansas City.
This model has been linked to a small number of infections caused by nontuberculous mycobacterium (NTM) at other hospitals in the United States and Europe. The U.S. Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) have advised hospitals that used this model between Jan. 1, 2012, and the present to notify patients of potential exposure to NTM.
Saint Luke’s has had no diagnosed cases of infection caused by exposure to NTM. We are confident we effectively reduce this already small risk to the best of our abilities.
What is nontuberculous mycobacterium?
NTM is a common bacterium found in soil and water, including tap water. It is slow-growing and harmless to most people. It can cause a specific infection called Mycobacterium chimaera (M. chimaera). This infection is rare and usually develops only in people with compromised immune systems. Symptoms can take months to years to develop. Most infections develop within four years of exposure.
How is NTM linked to heater-coolers?
A heater-cooler doesn’t come in direct contact with the patient or the patient’s blood. However, a reservoir within the device can collect water that contains NTM. During use, this water can evaporate and enter the operating room via the device’s fan. There is an extremely small risk that bacteria in the evaporated water could enter an open wound.
If there is no problem at Saint Luke’s, why are you sharing this information?
We do so out of an abundance of caution. Patient safety is our highest concern. We want all patients to have the information they need to make good health care decisions.
What are the symptoms of this NTM infection?
M. chimaera can resemble the flu. Other symptoms include a high fever that lasts more than a week, night sweats, or weight loss not attributed to other causes. People with surgical incisions may experience pain, redness, heat, or pus at the incision site. We encourage you to share this information with your primary care provider so you can be properly tested in the unlikely event you develop symptoms.
Is it treatable?
Yes. M. chimaera responds well to antibiotic treatments.
What kinds of surgeries use heater-cooler devices?
Saint Luke’s Hospital uses heater-coolers during liver transplant surgeries and several heart surgeries, including transplant, valve reconstruction, and device implantation. Less-invasive heart procedures—including transcatheter aortic valve replacement (TAVR), stents, pacemakers, or defibrillators—do not use heater-coolers.
What are the chances of being infected?
The CDC estimates the risk of infection at between .1 percent and 1 percent for patients who’ve undergone surgery with this device.
Can I be tested to see if I’ve been exposed?
If you aren’t having symptoms, you don’t need to be tested. There are a handful of laboratories in the United States equipped to handle M. chimaera diagnoses.
Can I take antibiotics to prevent infection?
There is no effective preventative at this time. In fact, the risks of treating an asymptomatic patient with antibiotics are more harmful than the potential benefit. Conventional macrolide antibiotic prophylaxis used in people who are immunosuppressed should be sufficient for any NTM exposure.
Is M. chimaera contagious?
No. You cannot catch it from a family member or friend.
Should I be worried even if I don’t have symptoms?
No. Saint Luke’s Hospital follows the most stringent disinfection and maintenance protocols and immediately implements recommendations as advised by manufacturers, the FDA, and the CDC.
What if my surgery took place before 2012?
Most patients who developed this infection displayed symptoms within four years. The CDC recommends notifying patients who’ve undergone these surgeries only since Jan. 1, 2012.
I’m scheduled for an upcoming procedure. How will you protect me?
We follow the strictest hygiene and disinfection protocols for a sterile environment to minimize exposure to any contaminant. We use filtered water in the heater-cooler, ensure the device is as far away from the patient as possible, and direct the air flow away from the surgical field. We also visually monitor the water circuit and replace tubing regularly.
Why haven’t the heater-cooler devices been recalled?
These devices are critical for life-extending surgeries and patient safety. Recalling them could cause more harm compared to the extremely small risk of exposure. The company recalled its instructions for use in 2015, and Saint Luke’s immediately took steps to ensure all new instructions and recommendations were followed.
If you have questions that were not answered here, please check the CDC’s website.