High-Level Disinfection

Objectives KEY CONCEPTS you will learn: What are the common methods of high-level disinfection How to perform each method

Instrument Processing Decontaminate Clean Sterilize Chemical High-pressure steam Dry heat High-Level Disinfect Boil Steam Chemical After use, instruments and other items should be decontaminated by soaking in a 0.5% bleach solution for 10 minutes. (Decontamination will help protect the person who is cleaning the instruments.) Then, physically wash the items until they are visibly clean. Finally, either sterilize or high-level disinfect the instruments. For a step-by-step description of this process, see the document “Instrument Processing” on the Resources page. Dry/Cool and Store

Exercise: Which Process to Choose, Chapter 9-174

High-Level Disinfection Principles: Destroys all microorganisms including HBV, HCV, and HIV; does not reliably kill all bacterial endospores Only acceptable alternative when sterilization equipment is not available HLD Principles Destroys all microorganisms, including HBV and HIV. Does not reliably kill all bacterial endospores. Only acceptable alternative when sterilization equipment is not available Source: Favero 1985; McIntosh et al 1994.

Common Methods of HLD Boiling Steaming Chemical

High-Level Disinfection Boiling Practices Boil instruments for 20 minutes. Always boil instruments in a pot with a lid. Start timing when the water begins to boil. Do not add anything to the pot after timing begins. Air-dry before use or storage. HLD Practices (boiling) Boil instruments and other items for 20 minutes (sufficient up to 5,500 meters/18,000 feet). Always boil for 20 minutes in a pot with a lid. Start timing when the water begins to boil. Do not add anything to the pot after timing begins. Air-dry before use or storage. Boiling instruments for 20 minutes will kill all microorganisms except bacterial endospores. In fact, most microorganisms will be inactivated if heated to 80 degrees C for 10 minutes. The boiling point of water is 1.1 degree C lower for each 1,000 feet of altitude; even at altitudes up to 5,500 meters (18,000 ft), the temperature will be adequate for HLD. Note: The highest temperature that boiling water will reach is 100 degrees C (212 degrees F) at sea level. Source: Favero 1985; McIntosh et al 1994.

High-Level Disinfection Steaming Practices Steam for 20 minutes. Be sure there is enough water in the bottom pan for the entire steam cycle. Bring water to a rolling boil. Start timing when the steam begins to come out from under the lid, Do not add anything to the pan after timing starts. Air-dry and store instruments in covered steamer pans.

Steamer Used for High-Level Disinfection

High-Level Disinfection by Steaming All vegetative bacteria, fungi ,and viruses killed by moist heat (80oC [176oF] for 10 minutes) A simpler, less expensive, and gentler process than boiling for plastic (e.g., syringes and MVA canulae) or rubber items Distillate is pure steam, unlike boiling water that contains calcium and other elements. Steamer Used for HLD

Chemical High-Level Disinfection Practices For HLD, a 0.1% chlorine solution shall be prepared from boiled water Decontaminate, clean, rinse and dry instruments, Cover all items completely with disinfectant, Soak for 20 minutes, Rinse thoroughly with boiled water three times, Air-dry before use and storage, Remove items using HLD or sterile forceps/gloves

Chemicals for HLD Chlorine solution 0.1% Formaldehyde 8% Vapors are irritating (staff should wear appropriate PPE) A potential carcinogen Do not mix with chlorine (can produce dangerous gas) Hydrogen peroxide 6% Highly corrosive and should not be used to disinfect copper, aluminum and zinc Loses potency rapidly when exposed to heat and light, N.B. - Chemical disinfectants should be stored in a cool, dark area, - Never store chemicals in direct sunlight or in excessive heat

Let’s analyze this picture: Which HLD method is it? Is the correct PPE used?