1. High-Level Disinfection

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

3. 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

4. Exercise: Which Process to Choose, Chapter 9-174

5. 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.

6. Common Methods of HLD
Boiling
Steaming
Chemical

7. 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.

8. 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.

9. Steamer Used for High-Level Disinfection

10. 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

11. 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

12. 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

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