Three patients who underwent heart surgery at Penn Presbyterian Medical Center contracted unusual infections linked to a heater-cooler, according to an article on the Philadelphia Enquirer website.
Heater-coolers heat or cool the blood of patients on a heart-lung bypass machine. The temperature is modulated by means of circulating water that does not come into contact with the patient's blood, so the device was not thought to pose a risk of infection.
Infectious-disease experts now say otherwise, because small amounts of water can become aerosolized and escape through a vent in the device.
At the same time, a University of Washington Medical Center investigation found that heater-coolers were contaminated with bacteria that cause Legionnaires' disease.