Recommendation Table 6.

Recommendations for a heater-cooler unit

Recommendations	Class a	Level b	Ref c
It is recommended that protocols for the detection of Mycobacterium chimaera infections, potentially associated with HCU, be adopted per institutional policies that follow ECDC standards.	I	B	81,87,91,98
Polymerase chain reaction methods, together with standard cultures, may be considered to increase accuracy thresholds to diagnose HCU contamination by NTM.	IIb	C	84
Sampling, cleaning and disinfecting procedures, according to the manufacturer or another validated protocol, must be implemented periodically, at a minimum yearly.	I	C	–
It is recommended that HCUs be placed outside operating rooms whenever possible to prevent the contaminated air from entering the operative field.	I	C	83,98
To reduce contamination of the operative field, the use of enclosures designed to direct HCU exhaust air directly out of the operating room and as far away from the patient as possible, maintaining a minimum distance of 2 metres, or the use of a vacuum for clearance of the exhaust, may be considered.	IIb	C	92,93

ECDC: European Centre for Disease Prevention and Control; HCU: heater-cooler units; NTM: non-tuberculous mycobacterium.

^aClass of recommendation.

^bLevel of evidence.

^cReferences.