PREVENTION OF PATIENT BACTERIAL-CONTAMINATION OF ANESTHESIA-CIRCLE-SYSTEMS - A CLINICAL-STUDY OF THE CONTAMINATION RISK AND PERFORMANCE OF DIFFERENT HEAT AND MOISTURE EXCHANGERS WITH ELECTRET FILTER (HMEF)

The microbiological contamination of 250 breathing system tubes after use in anaesthesia circle systems with reduced fresh gas flow was inve stigated. The lungs of 50 patients were ventilated without any filteri ng device between the endotracheal tube and the Y-piece. A total of 51 , 49 and 100 patients, respectively, were given different types of hea r and moisture exchanger with electret fitters (HMEF). With no filteri ng device the tubing system was contaminated by microorganisms origina ting from the patient's tracheal secretion in 13% of the patients. In contrast, no bacterial migration into the tubing system was detected w hen any of the investigated HMEF-devices were used. We therefore concl ude that heal and moisture exchangers with electret filters prevent co ntamination of the anaesthesia breathing system with microorganisms fr om the patients airways.