Microbiological safety and cost-effectiveness of weekly breathing circuit changes in combination with heat moisture exchange filters: a prospective longitudinal clinical survey

AIM To assess the safety and cost effectiveness of a usage for seven days of breathing circuit systems (BCSs) in combination with heat moisture exchanger filters (HMEF) in operation room anesthesia. METHOD In a prospective longitudinal clinical study, the contamination on high-risk surfaces (HMEF together with inner and outer surface of BCS) was monitored over 1, 2, 5, and 7 days. RESULTS of endogenous respiratory patient flora and contamination flora of BCS, HMEF and bag were compared. Costs of prolonged use of BCS together with HMEF up to 7 days were calculated. RESULTS Neither physiological respiratory flora nor colonizing pathogens of the oropharynx of the ventilated patients were transmitted through the filters at any time. None of the included patients developed a postoperative pneumonia. Using the BCS for 24 hours provides a cost savings of up to 40% versus single use. Extending the change interval from 24 hours to 48 hours saved over 50% compared to change after each patient, and an additional 19% compared to change after 24 hours. In combination with a HMEF BCS can be used up to 7 days without clinical risk on multiple patients in operation room settings. CONCLUSION Expanding the usage of berating in combination with usage of moist exchange filters is feasible, microbiologically safe and cost effective, as 41% of material costs per ventilation may be saved. Further research is needed to confirm these results.