Cleaning and disinfection of patient care equipment as an infection prevention strategy

Spaulding Classification Scheme

More than 30 years ago, Earle H. Spaulding devised a classification scheme for the disinfection and sterilization of patient care items and equipment. This scheme is based on classifying patient care equipment into the following categories: critical, semi-critical, or non-critical. The system also establishes three levels of germicidal activity (i.e., sterilization, high-level disinfection, and low-level disinfection) for strategies within the three classes of medical devices (critical, semi-critical, and non-critical).

Critical Medical Devices

Critical items enter sterile tissue or the vascular system (e.g., needles, indwelling urethral catheters) and pose a high risk of infection if they are contaminated with any microorganism. Therefore, critical items must be sterile, as any microbial contamination could transmit disease.

Semi-critical Medical Devices

Semi-critical items come into contact with mucous membranes or skin. These items include oral thermometers and respiratory therapy equipment. Semi-critical devices must be handled in the same way, regardless of whether the patient is known to be infected with HBV, HCV, HIV, or others. Some semi-critical items that may come into contact with the skin for a short period of time (e.g., bed rails) are usually considered non-critical surfaces and are disinfected with professional disinfectants. When an oral thermometer is used, it is recommended to use a probe cover to reduce the level of microbial contamination, but also to disinfect the thermometer after use using a product specially designed for medical instrumentation. Concentrated enzymatic disinfectant detergent for instrumentation.

Non-critical Medical Devices

Non-critical items are those that come into contact with the skin, but not with mucous membranes. The intact skin of a patient receiving care acts as a barrier to most microorganisms; therefore, the sterility of these items is “non-critical.” Non-critical items can be divided into two categories:

• Non-critical patient care items may include a blood pressure cuff, a stethoscope, a pulse oximeter, etc. There has been no documented risk of transmission of infectious agents to patients via non-critical items when they are used as non-critical items and do not come into contact with skin and/or mucous membranes.

• Non-critical environmental surfaces include floors, bedside tables, side rails of the bed, light switches, and patient bedding. However, many of these non-critical environmental surfaces are touched frequently and could contribute to secondary transmission through hand contamination, which is why periodic disinfection is necessary. In addition, proper hand hygiene is required for both medical staff and patients. Hand disinfectant gel

Cleaning Patient Care Equipment

Cleaning is the action of removing visible organic residues (e.g., blood and tissues) and inorganic salts from patient care equipment and preparing them for safe handling and/or subsequent decontamination. Cleaning should be performed using water with detergents or enzymatic products that are capable of removing visible organic and inorganic residues. Concentrated disinfectant detergent

Cleaning is done manually, through friction (i.e., manually scrubbing the soiled object with a cloth to remove dirt) and through fluidization (i.e., washing with a detergent or an enzymatic product with water), a “technical” way to describe the cleaning process using the “good old soap and water method.” Another method of cleaning is mechanical cleaning, which can be accomplished via a washer-disinfector (e.g., a dishwasher).

Equipment must be thoroughly cleaned before it can be disinfected. The physical action of scrubbing with a detergent or cleaning agent and rinsing with water (i.e., cleaning) removes a large number of microorganisms from soiled or contaminated surfaces. Thus, cleaning is a form of decontamination.

Disinfecting Patient Care Equipment

Disinfection is a process that eliminates most pathogenic microorganisms, with the exception of bacterial spores, from inanimate objects. Disinfection is not the same as sterilization, because the disinfection process does not kill bacterial spores. Only sterilization can eliminate all forms of microbial life, including spores. Other factors that influence the efficacy of disinfection are: the amount of dirt; the type and level of microbial contamination; the concentration and exposure time to the germicide; the physical nature of the object (e.g., cracks, hinges, and lumens); the presence of biofilms; the temperature and pH of the disinfection process. If patient care equipment is not cleaned properly, the object cannot be disinfected properly.

Critical medical devices and instruments that penetrate tissues or the vascular system or through which a sterile body fluid (e.g., blood) flows must be sterile.

The attending physician's recommendations, age, and health status of the patient determine whether items such as respiratory catheters or urethral catheters will be disinfected between uses or whether sterile products will be purchased and used only once.

Patient care equipment (e.g., blood pressure cuffs, stethoscopes) can be contaminated with infectious agents (e.g., MRSA) and can contribute to the transmission of infections. Therefore, non-critical surfaces should be disinfected at least when visibly soiled and on a regular basis. The term “on a regular basis” must be defined by a protocol established by each healthcare unit. However, it is suggested that vital signs equipment and supplies be cleaned and disinfected with a disinfectant after use and before being used on another patient.

Products used for disinfecting equipment in clinics and hospitals

Disinfectants are antimicrobial substances applied to objects and are generally not used on the skin, as they can cause tissue damage. Chemical disinfectants used in hospitals may contain alcohol, chlorine compounds, hydrogen peroxide, quaternary ammonium compounds, and iodophors.

Disinfection most frequently occurs by wiping a piece of medical equipment with a disposable cloth or a swab impregnated with a disinfectant. This is effective for small surfaces to achieve low-level disinfection. Supplies and other non-electronic products can also be submerged or soaked in a liquid disinfectant or disinfected via wet pasteurization (i.e., by boiling).

Another effective method is the use of disinfectant wipes and ready-to-use products. Sometimes, disinfectant wipes are not enough and the equipment must be sprayed with a disinfectant. Be careful, however; spraying electronic medical equipment, such as ventilators or infusion pumps, may present risks of corrosion of electronic circuits due to the penetration of disinfectant or cleaning solutions into the equipment housing. Typically, manufacturers recommend wiping the housing with a soft cloth dampened with a mild detergent and water.