Equipment-related infection risks

Abstract

The increasing use of complex medical equipment for treatment and diagnosis, and the increasing number of immunosuppressed or highly-susceptible patients have increased infection risks in recent years. These risks to patients and staff have been accentuated by equipment which is difficult to clean and is often heat-labile. Equipment may be classified as high or intermediate infection risk (Lowbury et al., 1981). High-risk items are associated with a break in the skin or mucous membrane or with insertion of an instrument into a sterile cavity. Most of these items can be autoclaved, e.g., surgical instruments and, in practice, the risk of transmission of infection is small. Instruments such as laparoscopes or arthroscopes are often required for several patients during a single operating session and are usually unable to withstand autoclaving. These endoscopes are commonly decontaminated by immersion in 2% glutaraldehyde for l&30 min which is not a sterilization procedure. Nevertheless, infection due to inadequate sterilization has not been reported. Cardiac catheters are difficult to clean and continued reprocessing may cause structural damage. These are usually sterilized with ethylene oxide but, again, there is little evidence of infection due to inadequate processing. Intermediate risk items are those in direct or indirect contact with mucous membranes or skin. Instruments in direct contact with the mucous membranes, e.g., gastrointestinal endoscopes and bronchoscopes, are potentially more hazardous than those with indirect contact, e.g., mechanical respiratory ventilators and associated circuits. Direct or indirect contact with skin is usually a lesser hazard, apart from the hands of staff, which are the most important vehicles of transmission of infection.