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This award-winning blog supplements the articles in Hospital Infection Control & Prevention.

Check your Surgical Heater-Cooler Devices due to spike in Post-Op Infections

An increase in Nontuberculous Mycobacteria (NTM) infections in post-surgical patients has been linked to contaminated water emitted from heater-cooler devices used in surgery. Infection preventionists and their clinical colleagues should immediately review cleaning and disinfection procedures for the devices and ensure only sterile water is used in them, public health agencies advise.

“The most important action to protect patients will be to remove contaminated heater-coolers from operating rooms, and ensure that those in service are correctly maintained,” the Centers for Disease Control and Prevention advises.

The Food and Drug Administration warns against using tap water to rinse, fill, refill or top-off the device water tanks since this may introduce NTM organisms. Use only sterile water or water that has been passed through a filter of less than or equal to 0.22 microns, the FDA notes. In addition, clinicians should direct the heater-cooler’s vent exhaust away from the surgical field to reduce the risk of aerosolizing tank water into the sterile field and exposing the patient.

Heater-cooler devices are often used during cardiac surgical procedures to warm and cool a patient’s blood during cardiopulmonary bypass. Commonly found in soil and water, NTM usually only threatens immune-compromised patients and is not transmitted from person to person. Bacterial growth is so slow that the patient may not become symptomatic until months or even years after the procedure. The CDC cited several recent reports of NTM infections1-3 in making the following recommendations:

Patients who have recently had cardiac or thoracic surgery should contact their health care provider if they have questions about possible exposure to a heater-cooler device. They should be aware that symptoms of NTM infection may include a combination of any of the following: fever, pain, redness, heat, pus around a surgical incision, night sweats, joint pain, muscle pain, and fatigue.

Healthcare facilities must ensure they are following the most current manufacturer’s instructions and FDA recommendations for maintenance, cleaning, disinfection and monitoring of heater-cooler devices. If a heater-cooler device tests positive for NTM or if there is concern for patient infections related to the heater-cooler device, review microbiological database and records of surgical procedures to identify any patients that have had NTM-positive cultures within four years following a cardiac surgery procedure. If a heater-cooler device is suspected to have led to patient infections or cultures positive for NTM, promptly notify your local health department, submit a report to FDA via MedWatch, and assess the need for notifying exposed patients in coordination with public health authorities.

Healthcare providers should have increased suspicion for NTM infections among patients who have signs of infection and a history of cardiac surgery. When seeing patients, actions that providers should consider include:

• Assessment for NTM infection for patients who report signs or symptoms of infection and who have had undergone cardiac surgery within the previous four years.

•Patients suspected to have an NTM infection should also be assessed for a history of cardiac surgery or exposure to a heater-cooler device. Note that other healthcare exposures such as injections, plastic surgery, and dialysis may also be associated with NTM infections and warrant consultation with public health authorities or reporting to FDA.


1. Kohler P, Kuster SP, Bloemberg G, et al. Healthcare-associated prosthetic heart valve, aortic vascular graft, and disseminated Mycobacterium chimaera infections subsequent to open heart surgery. Eur Heart Jrl 2015;Jul 17:pii: ehv342. [Epub ahead of print] Abstract

2.Sax H, Bloemberg G, Hasse B, et al. Prolonged Outbreak of Mycobacterium chimaera infection after open-chest heart surgery. CID 2015;61(1):67-75.

3.Mycobacterial infections associated with heater cooler units used in cardiac surgery: advice for providers of cardiac surgery. London: Public Health England; 2015.