Contamination of anesthesia circuits by pathogens

Rev Bras Anestesiol. 2011 Jan-Feb;61(1):50-9. doi: 10.1016/S0034-7094(11)70006-X.

Abstract

Background and objectives: Evaluation of contamination of anesthesia circuits by collecting 56 culture samples from the circular system; previously reprocessed tracheas by disinfection with 1% hypochlorite or 2% glutaraldehyde after being washed in non-sterile water and soap and dried by using compressed air and stored in surgical grade paper; and from other places of the non-reprocessed respiratory circuit, before anesthetic procedures.

Methods: Samples from the inspiratory and expiratory branches of the tracheas, canister, soda-lime, and collector jar (drain) through swab in Stuart medium and streaked in Agar blood, Mac Conkey, and Sabouraud growth media.

Results: The level of contamination with fungus and bacteria in the inspiratory and expiratory branches of tracheas reached up to 39.3% in some sites; in some cases, more than one microorganism was present, 75% fungal and 25% bacterial contamination. Cultures were positive for Candida sp., Dermatophytus sp., Penicillium sp., Aspergillus sp., Staphylococcus aureus, Staphylococcus saprophyticus, and Staphylococcus epidermidis. Contamination was observed in 25% of the canisters with growth of Candida sp., Penicillium sp., Dermatophytus sp., Aspergillus sp., and Fusarium sp. In the collector jar, a contamination rate of 36% was observed with growth of Candida sp., Dermatophytus sp., S. saprophyticus and Acinetobacter baumannii. Microorganisms did not grow in soda-lime cultures.

Conclusions: In all sites investigated except for soda-lime growth of microorganisms was observed with the possibility of cross infection.

MeSH terms

  • Anesthesiology / instrumentation*
  • Bacteria / isolation & purification
  • Candida / isolation & purification
  • Equipment Contamination*