The US FDA has issued an alert to healthcare facilities about the risk of nontuberculous mycobacteria (NTM) infections associated with the use of heater-cooler devices during cardiothoracic surgeries.
Heater-cooler devices, which are used during medical and surgical procedures to warm or cool a patient, include 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 warning stated.
Through the FDA’s analysis of adverse event reports, the medical literature, and information from national and international public health agencies, we are aware that the use of heater-cooler devices has been associated with Nontuberculous Mycobacteria (NTM) infections, primarily in patients undergoing cardiothoracic surgical procedures.
NTM organisms are widespread in nature and 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 and/or in individuals with compromised immune systems.
Between January 2010 and 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 MDRs were reported to the FDA in 2015. Some reports describe NTM infections related to cardiothoracic surgeries, but other reports do not specify the procedure the patient was undergoing.
In addition to standard precautions, the FDA recommends that facilities and staff using heater-cooler devices consider implementing the following measures to reduce risk to patients:
- Strictly adhere to the cleaning and disinfection instructions provided in the manufacturer’s device labeling. Ensure you have the most current version of the manufacturers’ instructions for use readily available to promote adherence.
- Do not use tap water to rinse, fill, refill or top-off 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.
- Direct the heater-cooler’s vent exhaust away from the surgical field to mitigate the risk of aerosolizing heater-cooler tank water into the sterile field and exposing the patient.
- Establish regular cleaning, disinfection and maintenance schedules for heater-cooler devices according to the manufacturers’ instructions to minimize the risk of bacterial growth and subsequent patient infection.
- Immediately remove from service heater-cooler devices that show discoloration or cloudiness in the fluid lines/circuits, which may indicate bacterial growth. Consult your hospital infection control officials to perform the appropriate follow up measures and report events of device contamination to the manufacturer.
- Submit a report to the manufacturer and to the FDA via MedWatch, as described below, if you suspect heater-cooler devices have led to patient infections.
- Read the FDA’s full recommendations here.
The FDA continues to evaluate reports through follow up with health care facilities and manufacturers to determine which factors may have contributed to the reported events.