Understanding Cleaning, Disinfection & Sterilization

Understanding the difference between cleaning, disinfection, and sterilization is crucial for ensuring patient safety and compliance with infection control standards. Each step in reprocessing medical devices plays a key role in reducing the risk of infection. This blog will break down these processes, highlight the devices used at each stage, and explain how Spaulding's Classification System determines the appropriate level of decontamination for different types of medical devices.

 

Cleaning

Cleaning is the first step in reprocessing reusable medical devices. It involves removing visible soil, blood, and other debris from instruments. Without proper cleaning, remaining contaminants can reduce the effectiveness of disinfection and sterilization.

• Devices used: Automated washers, ultrasonic cleaners, sinks and manual cleaning techniques.
• Process: Automated washers and ultrasonic cleaners effectively remove contaminants using mechanical action and cleaning agents. Ultrasonic cleaners are particularly useful for processing delicate or complex instruments with hard-to-reach areas.

 

Disinfection

Disinfection reduces the number of microorganisms to safe levels but does not necessarily eliminate all types, especially bacterial spores. This step is used for devices that don’t need to be fully sterile but must be safe for patient use.

• Devices used: Washer-disinfectors, endoscope washers, thermal disinfectors, and chemical disinfectant baths
• Process: Washer-disinfectors combine cleaning and disinfection, typically using heat or chemicals. In thermal disinfection, the A₀ 3000 standards used by Belimed devices ensures that the device has been exposed to sufficient heat and time to reduce microbes to a safe level for handling. This method is particularly important for semi-critical devices such as endoscopes.

 

Sterilization

Sterilization destroys all microorganisms, including bacteria, viruses, fungi, and spores. This is required for instruments that encounter sterile tissue or the bloodstream.

• Devices used: Steam sterilizers (autoclaves), chemical (low temp) sterilizers.
• Process: Steam sterilization is the most common method, using steam to kill all forms of microorganisms. Ethylene oxide and hydrogen peroxide sterilizers are sometimes used for heat-sensitive instruments. Sterilization must achieve a Sterility Assurance Level (SAL) of 10⁻⁶, meaning the chance of a surviving microorganism is less than one in a million. This guarantees that critical instruments, like surgical tools, are completely sterile before use.

 

Spaulding's Classification System

Spaulding's Classification System helps determine the level of reprocessing required for medical devices based on how they are used. It divides devices into three categories: critical, semi-critical, and non-critical, with each category requiring a different level of decontamination.

 

• Critical Items: These are devices that enter sterile areas of the body, such as surgical instruments or implants, which must be sterilized. 
  o    Devices used: Steam sterilizers or ethylene oxide sterilizers are commonly used for critical items to meet the SAL of 10⁻⁶, ensuring these instruments are fully sterile.
• Semi-critical Items: These devices contact mucous membranes or non-intact skin, such as endoscopes or dental tools, and require high-level disinfection. 
  o    Devices used: Washer-disinfectors or chemical disinfection are used for semi-critical devices, ensuring the microbial load is reduced to a safe level.
• Non-critical Items: These items, like stethoscopes and blood pressure cuffs, only encounter intact skin and require cleaning or low-level disinfection. 
  o    Devices used: Automated washers or ultrasonic cleaners can be used to safely clean non-critical items, removing visible debris before reuse.