Persistent contamination of heater–cooler units for extracorporeal circulation cured by chlorhexidine–alcohol in water tanks

Summary Recently, surgical site infections due to non-tuberculous mycobacteria (NTM) have been linked to heater–cooler unit contamination. The European Centre for Disease Prevention and Control and manufacturers now recommend the use of hydrogen peroxide in filtered water to fill heater–cooler unit tanks. After implementation of these measures in our hospital, heater–cooler units became heavily contaminated by opportunistic waterborne pathogens such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia . No NTM were detected but fast-growing resistant bacteria could impair their detection. The efficiency of hydrogen peroxide and chlorhexidine–alcohol was compared in situ . Chlorhexidine–alcohol treatment stopped waterborne pathogen contamination and NTM were not cultured whereas their detection efficiency was probably improved.