An alternative strategy for infection control of anesthesia breathing circuits: a laboratory assessment of the Pall HME Filter.

Contaminated breathing systems have been responsible for nosocomial upper respiratory tract and pulmonary infections in patients undergoing general anesthesia. The current infection control guidelines for anesthesia breathing circuits require single-patient use or high-level disinfection of breathing tubes, y-connector, and reservoir bag. An alternative infection control strategy has been suggested that incorporates placement of a microbial filter downstream from the y-connector between the circuit and the patient. This laboratory study assessed the capacity of the Pall HME Filter as a bidirectional barrier to transmission of bacteria between the y-connector of an anesthesia circle breathing system and a test lung. The investigators modified a sterile circle system to allow aerosolization of a suspension of 10(9) Micrococcus luteus over 5 h into the inspiratory limb proximal to the y-connector or downstream from the filter into the test lung. Cultures indicated that the Pall HME Filter placed between the y-connector and the test lung completely prevented transmission of bacteria in both directions. The results of this study suggest that the Pall HME Filter could be used as an effective microbial barrier between the anesthesia circle breathing system and the patient as part of an alternative strategy for infection control.