Heaters and chillers are often used in the hospital setting to cool patients down or to keep them warm during or after surgery. “Heater-cooler devices” are water tanks that provide temperature-controlled water to external heat exchangers or warming/cooling blankets through closed circuits.
A risk has arisen in use of such devices during cardiothoracic surgeries, where patients are either warmed or cooled to optimize medical care and improve patient outcomes. This risk centers on the water used to heat-up or cool-down the device, for the water can harbor microbial pathogens.
While the water 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. The generation of airborne contamination is known as aerosolization. Here contamination can enter the air in the form of water droplets, escaping through circuits via a device’s exhaust vent.
FDA notes the warning may well be applicable to other medical and surgical procedures.
The main pathogen risk is said to be Mycobacteria. Mycobacteria are widespread organisms, typically living in water (including tap water treated with chlorine) and food sources. Infections caused by these types of bacteria are difficult to treat. The group includes Mycobacterium tuberculosis, responsible, as the name suggests, for tuberculosis. The FDA warning concerns non-tuberculosis pathogens and these organisms of concern are associated with catheter infections, skin and soft tissue (especially post-cosmetic surgery) and pulmonary infections.
With the heater-cooler devices, FDA recommend that devices are examined regularly to see if they are at risk and are then properly maintained. Maintenance should include regular cleaning and disinfection. As a further protection sterile water, rather than tap water, should be used to fill the devices.
