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Bacterial contamination of anesthesia machines' internal breathing-circuit-systems

Verena Spertini1, Livia Borsoi, Jutta Berger

  • 1Clinical Institute for Hospital Hygiene, Medical University of Vienna, Vienna, Austria.

GMS Krankenhaushygiene Interdisziplinar
|January 14, 2012
PubMed
Abstract

Insights

Bacterial contamination is common in anesthesia breathing circuits, with 43% of machines showing growth. Proper reprocessing and hygiene are crucial to prevent infections and may allow for longer intervals between cleaning anesthesia equipment.

Area of Science:

  • Anesthesiology
  • Infection Control
  • Microbiology

Background:

  • Bacterial contamination of anesthesia breathing machines poses a risk for pulmonary and cross-infections.
  • While disposable equipment and filters exist, the internal breathing circuits are often assumed to be sterile.
  • Data supporting the sterility of internal breathing circuits is lacking.

Purpose of the Study:

  • To investigate microbial contamination within used anesthesia machine breathing-circuit systems.
  • To gather data for defining objective reprocessing intervals for anesthesia equipment.

Main Methods:

  • Investigated internal parts of 40 anesthesia machines' breathing-circuit systems.
  • Utilized Chi-square test and logistic regression analysis.
  • Conducted on-site observation of reprocessing procedures.

Main Results:

  • Bacterial growth detected in 17 out of 40 (43%) investigated machines.
  • No significant correlation found between contamination levels and reprocessing intervals.
  • Common contaminants included coagulase-negative Staphylococci, spore-forming bacteria, and Micrococcus species; E. coli and S. aureus were found in isolated cases.

Conclusions:

  • Contamination is primarily attributed to inadequate adherence to hygienic measures during reprocessing.
  • Findings suggest that current manufacturer recommendations for weekly reprocessing may be extended.
  • Emphasizes the critical importance of maintaining standard hygienic practices during the reprocessing of anesthesia apparatus.
Keywords:
anesthesia machinebreathing circuit systemcontaminationinfection control

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