The Food and Drug Administration (FDA) issued a safety announcement about infections associated with heater-cooler devices used during medical and surgical procedures and steps health care providers and health facilities can take to mitigate risks to patients.
Heater-cooler devices have been associated with nontuberculous mycobacteria (NTM) infections, primarily in patients undergoing cardiothoracic surgical procedures. Nontuberculous mycobacteria can cause pulmonary disease resembling tuberculosis.
Heater-cooler devices are used during cardiothoracic surgeries and other medical and surgical procedures to warm or cool a patient to optimize medical care and improve patient outcomes. The devices have water tanks that provide temperature-controlled water to external heat exchangers or warming/cooling blankets through closed circuits. Although the water in the circuits does not come into direct contact with the patient, there is the potential for contaminated water to enter other parts of the device or transmit bacteria through the air (aerosolize) through the device’s exhaust vent into the environment and to the patient, the FDA explains.
NTM organisms can be found in soil and water, including tap water sources. They are typically not harmful, but in rare cases may cause infections in very ill patients or in individuals with compromised immune systems.
From January 2010 to August 2015, the FDA received 32 medical device reports (MDRs) of patient infections associated with heater-cooler devices or bacterial heater-cooler device contamination. Twenty-five of these reports came in 2015. Some reports describe NTM infections related to cardiothoracic surgeries, but other reports do not specify the procedure the patient was undergoing. Eight reports were related to three events describing patient infections occurring in health care facilities in the U.S. The remaining 24 reports involved facilities outside the United States, most of these in Western Europe. The FDA said some patients presented with infections several months to years after their surgical procedures. Half of the 32 reports describe bacterial contamination of the heater-cooler device without known patient infection. The FDA is not aware of NTM infections acquired by hospital staff.
The FDA said it is challenging for a health care facility, health care provider, manufacturer, or patient to recognize NTM infections that may be associated with the use of or exposure to a particular medical device. The FDA continues to follow up with health care facilities and manufacturers to determine the factors that may have contributed to the events.
The FDA recommends that facilities and staff strictly adhere to cleaning and disinfection instructions provided by the manufacturer. Facilities should not use tap water to rinse, fill, refill or top off water tanks since this may introduce NTM organisms. Only sterile water or water that has been passed through a filter of less than or equal to 0.22 microns should be used. Ice needed for patient cooling during surgical procedures should be made from sterile water or water that has been passed through a filter of less than or equal to 0.22 microns. The heater-cooler’s vent exhaust should be directed away from the surgical field to mitigate the risk of aerosolizing heater-cooler tank water into the sterile field and exposing the patient.
The FDA said it is actively working with stakeholder groups to better understand the causes and risk factors for transmission of microbial agents associated with these devices and to develop strategies to minimize patient exposure.