Surgical operating theatres are supposed to be some of the most hygienic and sterile places in the world, and that goes double for those used for open-heart surgery. However, a recent study has found that many heater-cooler units used to maintain the temperature of a patient’s blood and organs during heart bypass provide a home for potentially lethal bacteria.
The research, presented to the 2017 APIC conference by John Rihs of Special Pathogens Laboratory, examined 653 water samples from 89 heater-cooler units located in hospitals around the US and Canada.
Of these, 33 units tested positive for the bacterium Mycobacterium chimaera, 4 were colonised with Legionella and 97 cultures were deemed uninterpretable due to extremely high levels of bacterial and fungal contamination.
Even though heater-cooler units use water tanks that provide temperature-controlled water through closed circuits, contamination presents an issue, as the water in them can still aerosolise and has the potential to transmit bacteria through the air to patients.
This transmission of bacteria can cause infections with non-specific symptoms that are slow to develop and difficult to diagnose. Such infections can go untreated for years, which makes them even more difficult to treat.
Rihs’ research highlights the need for hospitals to remain vigilant in monitoring the decontamination and maintenance schedules of heater-cooler units.
