Processing of Instruments for Disinfection

Processing of Instruments for Disinfection

Certain procedures in processing equipment are advised by the infection prevention practice to stop the spread of illness. It comprises high level disinfection, cleansing, and decontamination. After surgery, rinse surgical equipment under warm (not hot) running water to eliminate organic debris. Most blood tissues and fluids should be removed by rinsing. Never keep instruments in a dry container since this promotes the drying of blood and debris onto instrument surfaces and makes cleaning more challenging. When performing pre-cleaning, always use safety protective equipment. Pre-cleaning as soon as possible after use stops the growth of biofilm, safeguards instruments, and makes cleaning and decontamination easier.

Decontamination

Decontamination is a method of infection control that eliminates microorganisms from previously used tools. It is the procedure that makes objects safer for staff members to handle, particularly cleaning employees, prior to cleaning. Larger surfaces like an operating table, surgical tools, and gloves that have been contaminated with blood or bodily fluids during or after surgery are examples of such things. It renders some micronism inactive, such as HBV, HBC, and HIV, but not all of it. The WHO suggested using a 0.5% chlorine solution to clean equipment. 100g of chlorine solution (1 packet) is diluted with 1 water, then 91 water is added, and the solution is used for 24 hours.

Environmental Controls for Decontamination:

• Room should be negative pressure.
• Temperature: 60-65 F.
• Humidity: 30-60%.
• No fans or portable air conditioners.
• Correct personal protective equipment (PPE) must be used.

Steps of Decontamination

• Leave on surgical or examination gloves post-procedure or put on utility gloves,
• Place all instruments in freshly prepared 0.5% chlorine solution for 10 minutes for decontamination immediately after completing the procedure.
• Dispose of waste material in leak proof container or plastic bag
• Decontaminate examination or table or table or other surfaces contaminated during the procedure by wiping them with 0.5% chlorine.
• Remove instruments from 0.5% chlorine solution after 10 minutes and place them in water with shop or detergent.
• Clean instruments immediately (go to cleaning) or continue to soak in water until cleaning can be done.
• If wearing surgical or examination gloves, immerse both gloved hands in 0.5% chlorine solution. Remove the gloves by turning inside out.
• If disposing of gloves, place in a leak proof container or a plastic bag.
• If reusing the gloves, submerge in 0.5% chlorine solution for 10 minutes for decontamination. If wearing utility gloves, do not remove until instrument cleaning is finished.

Cleaning

Cleaning is the process that physically removes all visible blood, body fluids or any other foreign materials such as dust, dirt from the skin or inanimate objects. All blood, dried body fluids and tissue should be completely removed from the instruments prior to sterilization. It is the step of infection prevention. It prevents the growth of micro-organisms with detergent and water and physically removes organic materials such as blood and secretions. Use of a detergent is important for effective cleaning since water alone will not remove protein oils and grease. (Don't use abrasive vim, steel wool and hand soap.)

Steps of Cleaning

• Cover both hands with work gloves. Put the tool in a sink with some fresh, mild, non-abrasive detergent.
• Open the jaws of linked pieces and completely dismantle the instruments.
• Use a brush or cloth to thoroughly clean all instrument surfaces.
• Use a tiny brush to completely clean instruments' serrated edges.
• Wash surgical gloves inside and out with soapy water.
• Rinse every surface well in clean water to remove any soap or detergent residue.
• Air dry or use a clean, dry cloth to dry the instruments.
• Hang medical gloves up and let them air dry. Once they are entirely dry, store and rehang them to finish drying.
• Quickly dry all things after cleaning them.
  •  Do not leave items to dry in ambient air.
  •  Use a mechanical drying cabinet where ever possible.
  • Tubing and anaesthetic equipment must be dried using a drying cabinet.
  • Do not leave tubing hanging around to dry.
  • Use clean, lint-free cloths for all manual drying.
• The brush, gloves and washbasin which are used for cleansing the above equipment should be considered contaminated and must be cleaned thoroughly.

Packaging and Wrapping

• Act as a strong barrier against pollution.
• Keep sterility intact while in storage.
• Allow for the aseptic removal of the contents.
• Pack items such that steam can get inside.
• Pack items in a way that they can be opened and delivered quickly to a sterile field.
• Make use of the proper chemical monitor.
• Use a waterproof marker or label maker. Include the month, day, and year of the procedure.
• The hollowware
  • All openings to face the same direction.
  • Should not be able to move in pack.
  • Ensure items separated when nested.
  • Steripeel-place opening against the paper and not the plastic.

Sterilization

Sterilization is a process by which the pathogens as well as spores and viruses are destroyed. It is a process by which an article or material is rendered aseptic e.g. free from micro-organisms.

Purposes of Sterilization

• To destroy all pathogenic microorganisms including HIV viruses.
• To sterilize instruments and equipment used in the surgical practice.
• To keep the articles in such a condition that they are ready for use at any time.
• For the safety of the patient.

Method of Sterilization

• High pressure steam: Autoclave,
•  Dry Heat,
• Chemical,
• Low temperature and low moisture: Ethylene oxide sterilizers (EtO), Hydrogen peroxide plasma sterilizers and Peracetic acid sterilizing equipment.

Autoclave

Super saturated steam under pressure is known as autoclaving. It is the most widely used method of sterilization. It is non-toxic, inexpensive and sporicidal method. It should be used in surgical and medical instruments generally used with a 15lbs pressure for Unwrapped 20 min/wrapped 30 min, at a temperature of 1210c/2500f. This destroys spore forming bacteria as well as other bacteria and viruses. In autoclaving, the sterilization is done by steam under pressure. In an autoclave, water boils and its vapour pressure equals that of the surrounding atmosphere. When pressure increases inside a closed vessel, the temperature at which it boils also increases. Saturated steam has better penetrating power. When steam comes into contact with a cooler surface, it condenses into water and gives up its latent heat to that surface. This method of sterilization is suitable for medical instruments like forceps, scalpel, scissors, needles, syringes, linen, gauze, etc. These articles must be loosely packed in the wrappers for sterilization.

Precaution

• Never open the autoclave's exit valve or drainage tap while it is under pressure heating.
• Once the outlet valve is closed, never heat the autoclave too rapidly to increase pressure.
• When the pressure inside the autoclave is building, never leave it unattended.
• You risk getting scalded by steam if you open the lid before the pressure has returned to normal.
• Make sure the lid is on tightly during sterilization to prevent steam leaks. If so, neither the temperature nor the pressure will be adjusted.

Guidelines

• Prior to sterilization, all items must be cleaned, dried, and decontaminated.
• The item should be able to absorb steam via the wrapper and container.
• The instruments should be double wrapped in recently washed clothing or paper using an envelope or square wrap approach.
• Neither the contents nor the drum should be packed too tightly.
• Opened containers must be turned on their sides to allow the stem to reach the contents.
• All of the air in the chamber must be expelled before starting the autoclave, and it must be replaced with steam.
• Place the equipment packs on an autoclave shelf or cart, then place them inside the autoclave chamber to allow steam to freely circulate and reach all surfaces.
• Check water level before starting, steam should be escaping from pressure valve.
• When the autoclave is over, wait for half an hour to dry the materials.
• Sterilize the wrapped items for 30 minutes and unwrapped items for 20 mins, time with clock at 121 degree centigrade (250f) and 106 kpa (15 Ibs/in²)
• Place the sterilized packs on a surface padded with paper or fabric to prevent condensation.
• Allow the pack to reach the room temperature before storing and record sterilization condition (time, temperature and pressure) in a log book.

Flash Sterilizing (Flash Autoclaving)

Flash sterilization is considered acceptable for processing cleaned patient-care items that cannot be packaged, sterilized, and stored before use. It also is used when there is insufficient time to sterilize an item by the preferred package method. Flash sterilization should not be used for reasons of convenience, as an alternative to purchasing additional instrument sets, or to save time.

• This is only to be used for unsterile equipment that is needed unexpectedly.
• Porcelain in soapy water if necessary.
• Place in steam sterilizer for 15 mins at 132°C.
• Remove with sterile forceps or using sterile gloves

Dry Heat

For a hot air oven, a high temperature and relatively extended exposure durations are necessary. The process is carried out through heat conduction. It takes place for 60 minutes at a temperature of 170 °C (340 °F). This procedure is used to sterilize delicate goods such as blades, knives, scissors, and eye tools as well as items that might be harmed by wet heat or those are impervious to moist heat such as powders and petroleum compounds. Plastic wires, syringes, catheters, and tubes are examples of items that should not be sterilized using this method because they melt at high temperatures.

Advantages:

• All types of micro-organisms including spores are killed by this method.
• It is the safest method of sterilization.

Disadvantages

• It is a costly method of sterilization.

Guidelines

• Before putting glass in the oven, it must be completely dry.
• Place the metal container with the instruments in the oven and heat to the required temperature.
• After sterilization, the oven must cool for two hours before the door may be opened.
• It shouldn't be packed too full.
• It is important to arrange the items so that air can circulate freely.
• Once the desired temperature is attained, start the timer and hold the temperature there for the advised amount of time.
• Remove the containers after cooling, then store.

Chemicals

Pathogenic organisms are eliminated by the application of disinfection chemicals. The length of time needed to disinfect is inversely correlated with chemical strength. Formaldehydes and glutaraldehydes are often used disinfectants. By soaking for 10 hours in 2% gluteraldehyde and 24 hours in 8% formaldehyde, objects are sterilized. Another name for it is cold sterilization. The majority of bacteriostatic and bactericidal substances work against every type of microorganism, including HIV. All used tools or equipment must be thoroughly cleaned with clean water before using this procedure. Keep in mind that bacteria that form spores and those that react quickly to acids are more resistant to disinfectants.

Advantages

• This method is used to sterilize instruments which are damaged by heat and metallic objects prone to corrosion.
• It is an easy method.

Disadvantages

• A disinfectant cannot destroy the spores.
• Disinfectants are injurious to skin and the articles.

Guidelines

• A chemical disinfectant works by coagulating or altering the protein's makeup, preventing it from existing in the same form.
• Prepare a brand-new chemical sterilant solution or make sure the solution is not expired.
• Put the cleaned and dried goods in a solution of 2% glutaraldehyde or 8% formaldehyde. Cover everything in full.
• For formaldehyde, soak for at least 24 hours, or for gluteraldehyde, soak for the necessary amount of time (8–10 hours).
• To prevent skin contact, utilize gloves and eye protection.
• Use only in locations with good ventilation.
• Use sterile forceps to remove the apparatus from the solution.
• To get rid of any remaining chemical sterilant, thoroughly rinse the items in sterile water.
• Use the items immediately or place it in a sterile covered container.

High Level Disinfection

High level disinfection is the process that eliminates all microorganisms except bacterial endospores from inanimate objects by boiling, steaming and using chemical. HLD is only acceptable alternative when sterilization of equipment is either not available or not suitable.

Method Used in HLD

• Boiling
• Steaming
• Chemical

Boiling

Boiling in water is an effective way of disinfecting instruments. Boiling for 20 minutes will kill all vegetative forms of bacteria, viruses, yeast and fungi but will not kill all endospores.

Advantages

• It is a simple method.
• It is economical.

Disadvantages

• Certain bacteria, viruses and spores are resistant to boiling.
• This method cannot be used for sharp instruments.

Guidelines

• The equipment has to be spotless and devoid of organic matter.
• Submerge objects entirely in water.
• Only when the water has reached the boiling point is the article added.
• The glass objects are placed in cold water, covered in linen, and then heated to a boil.
• At high altitudes when the boiling point is less than 100°c, the boiling time is prolonged.
• Never submerge an instrument in water that is currently boiling.
• Keep the container's lid shut.
• Continually boil for 20 minutes.
• With highly sterile forceps or pickups, remove the items.
• Place in a container that is air dried, covered, and highly disinfected.

Steaming

All vegetative forms of bacteria are killed by moist heat at temperature of 60 to 75°c within 10 minutes.

Guidelines

• Place water in the bottom tray of the steamer which has no holes.
• Stack the steamer (pans maximum 3 pans) on the top of the pan containing water for boiling.
• Place cleaned instruments, gloves or other items into a steamer pans with holes.
• Cover the top steamer pan with a lid.
• Bring water to a rolling boil and wait for the steam to escape from between the top pan and the lid.
• Start timing and boil for 20 minutes.
• Remove the steamer pan from heat, gently shake excess water from items and place on an extra empty bottom pans.
• Allow to air dry and cool. (items can then be stored in the covered steamer pan)
• To use immediately, remove the items with HLD forceps and place in a high level disinfected covered container.

Chemical

The chemical substances known as disinfectants are used to kill pathogenic organisms. The stronger the chemical the lesser the time required for disinfection.

Advantages

• This method is used to sterilize instruments which are damaged by heat and metallic objects prone to corrosion.
• It is an easy method.

Disadvantages

• A disinfectant cannot destroy the spores.
• Disinfectants are injurious to skin and the articles.

Equipment can be disinfected by varieties of chemical solutions. The following chemicals are major types of chemicals for HLD.

• Formaldehyde 8% : for 20 mins
• Glutaraldehyde: for 20 mins
• 0.1% chlorine solution for 20 mins
• Hydrogen peroxide: 6%

Guidelines

• Prepare fresh solution of chemical sterilant or check to be sure solution is not out of date.
• Submerge the cleaned and dried items in 2% gluteraldehyde or 8% formaldehyde solution. Completely covering all items.
• Cover the container and soak for 20 minutes.
• Remove the items from the chemical solution using sterile gloves or sterile forceps.
• Rinse the items thoroughly with sterile water to remove all the traces of chemical sterilant.
• Use the items immediately or place it in a sterile covered container.

Commonly Used Disinfectants

Cidex

Composition: Gluteraldehyde, 2% acidic solution. It kills all pathogens. It is bactericidal, tuberculocidal, preudomonacidal, viricidal and fungicidal.

Time: Complete disinfection is 10 minutes, sporicidal within 7 to 8 hours.

Uses:

• Tray system of sterilization with cidex for large instruments, fiber-optic scopes and endoscopes with lenses.
• Sterilization of small and sharp instruments, catheters and thermometers.
• Sterilization of equipment of anaesthesia and of inhalation therapy.

Special Remarks:

• Best disinfectant with rapid action.
• Cidex is effective even in the presence of protein material.
• Recommended time is 10-hours to take care of the deep crevices in the instruments.

Hydrogen Peroxide

Hydrogen peroxide is highly disinfectant. It is not an antiseptic but a cleansing agent. It has oxidizing ability. 6% solution is required for the equipment to get disinfected in less than 30 minutes. After immersion the instruments must be rinsed with sterile water and wiped with a sterile towel.

Preparation

Six percent solution is prepared by mixing one part of hydrogen peroxide solution full strength (30%) of 4 parts of water. It must be handled with care, because it is corrosive. It should not be used with zinc, brass, copper and aluminium instruments.

• Mechanisms and uses
• It destroys anaerobic organisms and, therefore, used for cleaning the wounds infected or contaminated with anaerobes.
• It produces frothing and brings out debris from the depth of the wound.
• It produces heat when it comes in contact with the tissues. So it prevents capillary oozing and hence it is used as haemostatic solution whenever there is capillary oozing e.g. after incision and drainage.
• Used in cleaning wounds, bleaching, boils and as a throat spray and mouth wash. Very diluted form is used in ear-syringing to remove wax and foreign body.
• Used to remove blood stains from clothes.

Phenolic Compounds

It is very stable, effective even in presence of organic matter and widely used.

Phenol: It is dark in colour and a strong irritant. Pure form may cause skin burns. It has the smell of "life boy soap".

Composition: 0.51% Carbolic acid.

Uses

• Disinfection of sharp instruments in 100% solution, the instruments should be immersed for 2-3 hours and in 20% solution for 24 hours.
• Disinfection during cholera epidemic for disposal of excreta.
• Diluted solution is used for disinfection of dog bite wounds.
• Carbolization of appendicular stump.
• Phenol in almond oil is used as an injection treatment for the first degree of internal piles.

Lysol

It has dark brown Lysol. It is an irritant chemical and causes burns when it comes in contact with the skin. Instruments should be cleansed with sterile water before used.

Dilution and use: 1:100 in water. It is used for sterilization of sharp instruments e.g. needles, knives, scissors, etc.

Time: 30 minutes for 100% solution and 1-2 hours for 1:1000 solutions.

Chloroxylenol (Dettol)

• 2.5% for thermometers (disinfects in five minutes).
• 5% for instruments and plastic equipment. (disinfects 5 in 15 minutes).
• 5% for wounds it is more easily inactivated organic matter than other compounds.

Spirit Composition: Alcohol (optimum concentration of 70% alcohol is highly effective)

Uses:

• Disinfection of skin before intramuscular and intravenous injections.
• Removal of iodine in preparation of skin for operation.
• Cleaning the stitched wound.
• Cleaning the skin of the surrounding ulcer or open wounds.
• As it dissolves the greasy material, 50% spirit in water (gutta spirit) is used as ear drops.
• Used along with other disinfectants, such as iodine spirit and cetavlon spirit, for painting the parts before operation.

Savlon (Hospital Concentrate)

It is a cleansing agent having disinfectant properties as well. This is widely used in 1% solution for cleaning the skin before cleansing of wound.

Colour: Tartrazine (Yellow)

Properties and effects: Germicide and detergent

Fumigation: Fumigation is disinfection by exposure to the fumes of vaporized disinfectant or use of fumes or gases to destroy organisms. Saquil en boa ei o

Fumigation with sulphur: The room should be filled with steam form a kettle. Place sulphur in an earthen ware which is kept in a large container with water. Pour methylated spirit over the sulphur. Put the sulphur a far and close the room.

Fumigation with formalin: It is done with potassium permanganate crystals and formalin are used for this purpose. Mix and place them in a metal bowl. For 100 cu feet 140 gm of KM,0, and 250 ml at formalin are to be used, then the room should be closed completely and seated for 24 hrs for effective disinfection.

Types of Sterilization Monitors (Validation of Autoclave)

Mechanical Indicator: Temperature, Pressure

Chemical Indicator: Used to detect potential sterilization failures that could result from incorrect packaging or loading of sterilizer, or malfunctions of sterilizer. It should be on outside of each package to show it has gone through sterilization process.

Bowie-dick test: Used to assess the sterilizer's ability to remove air.

Indicator tape: Used to differentiate items that were exposed from those that were not.

Biological Indicator (Spore strip test): Biological indicators (BI) are the only monitor that directly measures cycle lethality.

Guidelines

• Place directly over drain, on lowest shelf of sterilization cart/rack.
• Run sterilizer per manufacturer's directions.
• Ensure processed indicator and control are from same lot.
• Incubate for specified time. Incubation time varies with product.
• Read and record results.
• Processed biological should be negative (purple).
• If positive (yellow): Sterilization process has failed due to improperly processed load, failure to meet temperature or exposure parameters, mechanical problems, etc.

Date Expiry of Equipment

• Steam under pressure: Linen pack: 1 week
• Pouch Pack: 1 month

Storage and Handling

• Should be Dust, Moisture, Insect and vermin free area.
• Not in strong sunlight
• Store items at least
  • 8" from floor
  • 18-20"mm from ceiling
  • 8" from exterior wall
• Room Temperature range is 18°C 22°C
• Relative humidity range is 35% - 68%
• Surfaces should be Non-porous, Smooth, Capable of being easily cleaned, and no wood, concrete or chipboard used.
• Storage containers should comply with the same requirements.