Contamination of anaesthetic machines with pathogenic organisms*

Abstract

SummaryHospital-acquired infections are commonly resistant to antibiotics and cause substantial morbidity and mortality in susceptible populations. Although there is no direct contact between the anaesthetic machine's controls and the patient, there is considerable potential for colonising organisms to be carried between the anaesthetic machine and the patient on the anaesthetist's hands. We performed two cross-sectional studies of bacterial contamination on anaesthetic machines before and after a simple intervention. Without warning, during theatre sessions, bacterial cultures were obtained from anaesthetic equipment. A new departmental policy of cleaning anaesthetic equipment with detergent wipes between cases was then introduced. Six weeks later, again without warning, a further set of cultures was taken. There was significant reduction in the proportion of cultures containing pathogenic bacteria (from 14 ⁄ 78 cultures (18%; 95% CI 9.4-26.5%) before the intervention to 5 ⁄ 77 cultures (6%; 95% CI 1.0-12%) after the intervention (p = 0.03)). The intervention was quick, easy and enthusiastically taken up by the majority of staff. We conclude that cleaning of anaesthetic equipment between cases should become routine practice.

The microbiological and sustainability effects of washing anaesthesia breathing circuits less frequently

“…Randomising individual circuits, which would have eliminated selection bias, would have been desirable, but was considered impractical. We did not examine the circuit exterior which, in our hospital, is routinely cleaned between uses with chlorhexidine . Our microbial testing was limited to bacterial contamination count with no speciation.…”

Passage of pathogenic microorganisms through breathing system filters used in anaesthesia and intensive care

“…We can find no evidence in the literature of cross‐contamination between patients when filters were in use. However, many patients throughout the world have been infected with tuberculosis from early ventilators that could not be sterilised [24], and our previous work has demonstrated a possible route for cross‐infection through contaminated external surfaces of anaesthetic equipment [25].…”

Lack of Correlation between Age and/or Gender with the Force Utilized in Cleaning an Anesthesia Machine

“…[2][3][4]9 One study described improved cleaning and disinfection procedures for anesthesia machines following reports of contamination on the machine's surface. 10 Others have reported the need to consider human factors when developing cleaning protocols. 11 However, none have specifically analyzed a crucial human factor involved in the cleaning process: the force used by the individual to clean the surface.…”