ASEPTIC TECHNIQUE GUIDE
Terminology: -
Sepsis: Presence of living pathogenic microorganism within the tissue
Sterile: Presence of no microorganism
Sanitize: Reduction of the number of microorganisms to a safe level
Antiseptics:
They are drugs, substances, or chemicals that applied topically to the living tissue to kill microorganisms
Disinfectants:
They are drugs, substances, or chemicals that applied to inamonate objects or non-living surfaces to kill microorganisms
Characters of ideal antiseptic or disinfectant: -
1-It is safe, not absorbed by the skin of the animal, and neither harmful (has adverse effect) to living tissue nor corrosive for non living surfaces
2-Highly effective against all microorganism at low concentration
3-Effective in presence of organic matter 5-Incompatable with other drugs
4-Soluble in water, stable, penetrate tissue surface 6-Fast acting with long duration
7-Non staining and odorless
Mechanism of action of antiseptics and disinfectants: -
1-Coagulation of bacterial cell protein
2-Ulteration of cell wall permeability leading to loss of essential substances or entry of unneeded substances
3-Interference with enzymatic system
Classification of disinfections: -
I-PHYSICAL: -
Physical sterilization by dry or moist heat is the most commonly used method of sterilization. 1-Dry heat (baking, flaming): -
A-Direct flaming: -
Advantages:
Simple and cheap method
Disadvantages:
Dullness of sharp instruments
B-Hot air (Oven): -
It is an effective method of sterilizing metal instruments and glassware (1-2 hours at a temperature over 200°C)
Advantages:
Excellent method of sterilization
Disadvantages:
1-High cost
2-It is not suitable method of sterilization of plastic or rubbery materials
2-Moist heat: -
It is commonly used method of sterilizing instruments, clothes, suture materials, and any other utensils
A-Boiling: -
Boiling by using distilled water in which has been added sodium carbonate 2 % at 100°C for at least 20 minutes can be used for sterilization of suture material, syringes and needles
Advantages:
Simple and cheap method
Disadvantages:
It is not recommended for aseptic surgery since;
1-It is not effective in killing bacterial spores
2-It tends to dull sharp instruments
B-Steam under pressure sterilization (autoclaving): -
It can be done at 120°C and 1.5 lb/ square inch atmosphere pressure for 1 to 2 hours. Advantages:
1-It is a good penetrating, bacteriocidal and economical method
Disadvantages:
1-It dulls sharp instruments 2-It scorchs fabrics
3-It may leave packs wet 4-It will not sterilize grease or oil materials
II-CHEMICAL: -
1-Oxidizing agents: -
These substances liberate nascent oxygen and so it is affected by the presence of organic matters
A-Halogens (Chlorine)
B-Peroxides (H2O2)
C-Potassium permanganate
2-Reducing agents: -
-An example of reducing agent is formaline, which is formaldehyde 40% in water.
-It is not affected by organic matter and has the ability to form toxoid with bacterial toxins
-It can be used as urinary antiseptic in acidic urine, as it is released from hexamine
-It can be used in the form of gas when mixed with Potassium permanganates.
3-Heavy metal: -
A-Mercury salts
i-Mercuric chloride used as skin antiseptic
ii-Mercuric nitrate and oxide used as eye ointment
iii-Bin iodide of mercury % in lanoline used as blister or counter irritant
iv-Organic mercury compounds act as disinfectants by liberating mercury ions as thiomersolates for wounds, skin, and instruments
B-Silver salts
Silver nitrate is an astringent that can be used for corneal ulcers
C-Copper salts
Copper sulfate % can be used as astringent fungicidal and germicidal
D-Zinc salts
Like zinc sulfate, zinc oxide, and zinc chloride
E-Arsenical salts
Arsanilic acid can be used orally as intestinal antiseptic
4-Acid and alkalis: -
Caustic soda and quick lime can be used for disinfection of buildings but they are corrosive
5-Alcohols: -
Ethyl alcohol 70% can be used for skin disinfection
6-Phenol and its derivatives
A-Phenol
It can be used as 2% solution for disinfection, or it can be used as it is for corneal ulcers
B-Crysol
Used as 0.5- % as intestinal antiseptic
C-Lysol
It can be used for disinfection of non-living objects
D-Chloroxylenol (Dittol®)
It is none irritant antiseptic for intact skin in concentration of 2%
E-Picric acid
It is used as antiseptic for burns
7-Alcohol formaline mixture at equal volumes or organic dyes such as acriflavin: -
They are used for sterilization of optical instruments and catheters
8-Gas sterilization with Ethylene Oxide gas (EO): -
Advantages:
1-It is both bactericidal and sporicidal
2-Their penetration and effectiveness at relatively low temperatures make them useful for sterilizing surgical supplies made of leather, wool, paper, plastics and other materials that would be damaged by the heat
3-It sterilizes electrical and optical equipment effectively and do not dull instruments
Disadvantages:
Materials that have been sterilized with Ethylene Oxide must be aerated for 1 to 7 days, depending on the material, otherwise residual gas may diffuse from the goods and irritates living tissues.
To perform aseptic surgery technique, strict measures should be taken to prevent contamination of the surgical wound, and to achieve this, the operating room, the surgery packs, the patient, and the surgeon must follow rigid routine procedures to insure such aseptic surgery technique
1-Operating or surgery room: -
Construction of operating room:
1-It is preferred to be isolated 2-It must be subjected to rigid policies
3-It should be with one exit in order to restrict unnecessary movement of personnel as well as to minimize the opening and closing of doors during surgery
4-The operating room should be in direct connection with the surgery preparation room and the surgical scrub area (used for preparation of surgical patients and as a post surgical recovery room)
5-The operating room should be supplied with good lighting facilities, casting beds and cushions operating tables and instrument carts and trolleys. Permanently installed hydraulic operating table is likely to be encountered in large animal surgery room. When circumstances entail that surgery must be carried out in an open yard, the clinician must select the site most suitable for the procedure.
6-If a minor surgical procedure is to be carried out on the standing position, measures should be taken, to secure the animal either in stanchion or in a box stall. When recumbency is mandatory, consideration must be given to the area or location in which the surgery will be performed preferably in a grass field or paddock in which a casting bed is required. The major drawbacks to this are the saturation of air with dust as well as the insect problems.
Surgery room cleanliness:
1-Cleaning of the surgery room should be done by well-trained housekeeping personnel
2-Daily cleaning consists of damp dusting of all flat surfaces, lights and furniture approximately one hour before surgery
3-Weekly cleansing routines must be established and it consists of whipping down of walls and ceilings with a germicidal cleaning solution. Cabinets and other operating room equipment should be cleansed. Operating tables should be cleansed after each operation with germicidal solution.
4-Buckets should be carefully cleansed and disinfected.
5-After surgery, areas contaminated by organic debris like blood should be cleaned with detergent and disinfectant
2-Surgery Packs: -
All materials and equipment used in a surgical procedure or entering the operative field must be sterilized.
1-Instruments and materials must be clean prior to sterilization
2-Post-operative cleaning to remove blood can be facilitated by soaking all materials and instruments in cold water and detergent
3-Gowns, drapes and other fabrics must be laundered
4-After drying the equipment and supplies they are arranged for pack preparation
5-The instruments and materials included in a pack vary with the surgical procedure or with the surgeon preference. All materials are packed either in sterilizing drums or wrapped with clean towel and double thick paper without contamination. Autoclaving is the most widely used method of surgical pack sterilization. Properly wrapped sterilized packs will remain sterile for up to 6 months if properly stored. Packs stored in sealed plastic bags remain sterile for up to one year.
3-Preparation of the operative site: -
Preparation of the operative site includes the following;
1-Clipping of hair which is best achieved by the use of an electric clipper. Shaving the hair coat is not always preferable since it takes long time for shaving an area and it produces erythema of the shaved skin.
2-Cleansing with a surgical scrub agents such as povidon iodine (Betadine®) or hexachlorophene and warm water to remove dirt and water insoluble materials. Scrubbing with a sponge should be in a circular manner starting at the incision site and moving outwards to the periphery then the sponge is discarded. Scrubbing of the operated area should be twice.
3-A germicidal solution such as alcohol 70 % is applied.
4-A skin antiseptic solution, preferably 2.5 % tincture iodine is applied.
Draping the patient:
The basic set of drapes pack consists of 4 pieces each approximately 120x90 cm and one main drape 200x205 cm with a rectangular window. The caudal drape is applied first, leaving a double thickness adjacent to the prepared area. The cranial drape is applied in a similar manner. The side drapes are then placed, leaving a suitable area exposed for the incision. The drapes are held in position with towel forceps. The patient and the entire operating table are then covered with the main drape that has a window. The window should enclose the area of the incision. The head of the patient is left uncovered for purposes of observation during surgery.
4-Preparation of the surgeon and assistants: -
1-Members of the surgical team and operating room personnel should be appropriately clothed.
2-Observation gowns and disposable shoe covers can be worn over the usual clothes of operating room personnel and others entering the operating room.
3-Caps and masks are also necessary.
4-Cloth flaps, masks and gowns must be laundered after each use
Preparation of the hands:
1-Before preparation of the hands for sterile surgery, the fingernails are cut short.
2-The cap and mask should be worn before scrubbing commences.
3-A deep sink with facilities that permit the adjustment of water flow without touching the faucet is very useful (a knee or foot control is preferred). Warm water should be used for scrubbing. The surgical scrubbing agents of preference are povidone-iodine and hexachlorophene. The hands and forearms are washed for 30 to 60 seconds with the surgical scrub. The hands are then scrubbed with a sterile brush with stiff bristles, scrubbing agent and water. Each surface of each finger should be scrubbed as well as the surface of the hands and arms with special attention to the nails and between the fingers. The process is repeated on the opposite arm. Scrubbing should be not less than 5 minutes. Both arms are then rinsed with the hands still held above the elbows. The application of alcohol 70 % to the hands and forearms following scrubbing is preferred, then drying of the hands and arms by means of sterile towel.
Gowning and Gloving:
The sterile gown and towel wrap or drums are opened by an assistant. The gown is lifted from the sterile wrap and held away from the table. The surgeon unfolds the gown by placing his hands in the appropriate armholes. The arms are pushed in the sleeves to the cuff. An assistant closes the neck and ties the inside waist tie. The gloves are worn and folded over the cuffs of the sleeves. Some operations need rigid aseptic precautions so that two pairs of gloves should be worn.
The instruments:
Instrument trays are presented, with the assistant carefully removing the paper wrap or cover. The surgeon places the instruments on the sterile wrapped instrument stand.
Terminology: -
Sepsis: Presence of living pathogenic microorganism within the tissue
Sterile: Presence of no microorganism
Sanitize: Reduction of the number of microorganisms to a safe level
Antiseptics:
They are drugs, substances, or chemicals that applied topically to the living tissue to kill microorganisms
Disinfectants:
They are drugs, substances, or chemicals that applied to inamonate objects or non-living surfaces to kill microorganisms
Characters of ideal antiseptic or disinfectant: -
1-It is safe, not absorbed by the skin of the animal, and neither harmful (has adverse effect) to living tissue nor corrosive for non living surfaces
2-Highly effective against all microorganism at low concentration
3-Effective in presence of organic matter 5-Incompatable with other drugs
4-Soluble in water, stable, penetrate tissue surface 6-Fast acting with long duration
7-Non staining and odorless
Mechanism of action of antiseptics and disinfectants: -
1-Coagulation of bacterial cell protein
2-Ulteration of cell wall permeability leading to loss of essential substances or entry of unneeded substances
3-Interference with enzymatic system
Classification of disinfections: -
I-PHYSICAL: -
Physical sterilization by dry or moist heat is the most commonly used method of sterilization. 1-Dry heat (baking, flaming): -
A-Direct flaming: -
Advantages:
Simple and cheap method
Disadvantages:
Dullness of sharp instruments
B-Hot air (Oven): -
It is an effective method of sterilizing metal instruments and glassware (1-2 hours at a temperature over 200°C)
Advantages:
Excellent method of sterilization
Disadvantages:
1-High cost
2-It is not suitable method of sterilization of plastic or rubbery materials
2-Moist heat: -
It is commonly used method of sterilizing instruments, clothes, suture materials, and any other utensils
A-Boiling: -
Boiling by using distilled water in which has been added sodium carbonate 2 % at 100°C for at least 20 minutes can be used for sterilization of suture material, syringes and needles
Advantages:
Simple and cheap method
Disadvantages:
It is not recommended for aseptic surgery since;
1-It is not effective in killing bacterial spores
2-It tends to dull sharp instruments
B-Steam under pressure sterilization (autoclaving): -
It can be done at 120°C and 1.5 lb/ square inch atmosphere pressure for 1 to 2 hours. Advantages:
1-It is a good penetrating, bacteriocidal and economical method
Disadvantages:
1-It dulls sharp instruments 2-It scorchs fabrics
3-It may leave packs wet 4-It will not sterilize grease or oil materials
II-CHEMICAL: -
1-Oxidizing agents: -
These substances liberate nascent oxygen and so it is affected by the presence of organic matters
A-Halogens (Chlorine)
B-Peroxides (H2O2)
C-Potassium permanganate
2-Reducing agents: -
-An example of reducing agent is formaline, which is formaldehyde 40% in water.
-It is not affected by organic matter and has the ability to form toxoid with bacterial toxins
-It can be used as urinary antiseptic in acidic urine, as it is released from hexamine
-It can be used in the form of gas when mixed with Potassium permanganates.
3-Heavy metal: -
A-Mercury salts
i-Mercuric chloride used as skin antiseptic
ii-Mercuric nitrate and oxide used as eye ointment
iii-Bin iodide of mercury % in lanoline used as blister or counter irritant
iv-Organic mercury compounds act as disinfectants by liberating mercury ions as thiomersolates for wounds, skin, and instruments
B-Silver salts
Silver nitrate is an astringent that can be used for corneal ulcers
C-Copper salts
Copper sulfate % can be used as astringent fungicidal and germicidal
D-Zinc salts
Like zinc sulfate, zinc oxide, and zinc chloride
E-Arsenical salts
Arsanilic acid can be used orally as intestinal antiseptic
4-Acid and alkalis: -
Caustic soda and quick lime can be used for disinfection of buildings but they are corrosive
5-Alcohols: -
Ethyl alcohol 70% can be used for skin disinfection
6-Phenol and its derivatives
A-Phenol
It can be used as 2% solution for disinfection, or it can be used as it is for corneal ulcers
B-Crysol
Used as 0.5- % as intestinal antiseptic
C-Lysol
It can be used for disinfection of non-living objects
D-Chloroxylenol (Dittol®)
It is none irritant antiseptic for intact skin in concentration of 2%
E-Picric acid
It is used as antiseptic for burns
7-Alcohol formaline mixture at equal volumes or organic dyes such as acriflavin: -
They are used for sterilization of optical instruments and catheters
8-Gas sterilization with Ethylene Oxide gas (EO): -
Advantages:
1-It is both bactericidal and sporicidal
2-Their penetration and effectiveness at relatively low temperatures make them useful for sterilizing surgical supplies made of leather, wool, paper, plastics and other materials that would be damaged by the heat
3-It sterilizes electrical and optical equipment effectively and do not dull instruments
Disadvantages:
Materials that have been sterilized with Ethylene Oxide must be aerated for 1 to 7 days, depending on the material, otherwise residual gas may diffuse from the goods and irritates living tissues.
To perform aseptic surgery technique, strict measures should be taken to prevent contamination of the surgical wound, and to achieve this, the operating room, the surgery packs, the patient, and the surgeon must follow rigid routine procedures to insure such aseptic surgery technique
1-Operating or surgery room: -
Construction of operating room:
1-It is preferred to be isolated 2-It must be subjected to rigid policies
3-It should be with one exit in order to restrict unnecessary movement of personnel as well as to minimize the opening and closing of doors during surgery
4-The operating room should be in direct connection with the surgery preparation room and the surgical scrub area (used for preparation of surgical patients and as a post surgical recovery room)
5-The operating room should be supplied with good lighting facilities, casting beds and cushions operating tables and instrument carts and trolleys. Permanently installed hydraulic operating table is likely to be encountered in large animal surgery room. When circumstances entail that surgery must be carried out in an open yard, the clinician must select the site most suitable for the procedure.
6-If a minor surgical procedure is to be carried out on the standing position, measures should be taken, to secure the animal either in stanchion or in a box stall. When recumbency is mandatory, consideration must be given to the area or location in which the surgery will be performed preferably in a grass field or paddock in which a casting bed is required. The major drawbacks to this are the saturation of air with dust as well as the insect problems.
Surgery room cleanliness:
1-Cleaning of the surgery room should be done by well-trained housekeeping personnel
2-Daily cleaning consists of damp dusting of all flat surfaces, lights and furniture approximately one hour before surgery
3-Weekly cleansing routines must be established and it consists of whipping down of walls and ceilings with a germicidal cleaning solution. Cabinets and other operating room equipment should be cleansed. Operating tables should be cleansed after each operation with germicidal solution.
4-Buckets should be carefully cleansed and disinfected.
5-After surgery, areas contaminated by organic debris like blood should be cleaned with detergent and disinfectant
2-Surgery Packs: -
All materials and equipment used in a surgical procedure or entering the operative field must be sterilized.
1-Instruments and materials must be clean prior to sterilization
2-Post-operative cleaning to remove blood can be facilitated by soaking all materials and instruments in cold water and detergent
3-Gowns, drapes and other fabrics must be laundered
4-After drying the equipment and supplies they are arranged for pack preparation
5-The instruments and materials included in a pack vary with the surgical procedure or with the surgeon preference. All materials are packed either in sterilizing drums or wrapped with clean towel and double thick paper without contamination. Autoclaving is the most widely used method of surgical pack sterilization. Properly wrapped sterilized packs will remain sterile for up to 6 months if properly stored. Packs stored in sealed plastic bags remain sterile for up to one year.
3-Preparation of the operative site: -
Preparation of the operative site includes the following;
1-Clipping of hair which is best achieved by the use of an electric clipper. Shaving the hair coat is not always preferable since it takes long time for shaving an area and it produces erythema of the shaved skin.
2-Cleansing with a surgical scrub agents such as povidon iodine (Betadine®) or hexachlorophene and warm water to remove dirt and water insoluble materials. Scrubbing with a sponge should be in a circular manner starting at the incision site and moving outwards to the periphery then the sponge is discarded. Scrubbing of the operated area should be twice.
3-A germicidal solution such as alcohol 70 % is applied.
4-A skin antiseptic solution, preferably 2.5 % tincture iodine is applied.
Draping the patient:
The basic set of drapes pack consists of 4 pieces each approximately 120x90 cm and one main drape 200x205 cm with a rectangular window. The caudal drape is applied first, leaving a double thickness adjacent to the prepared area. The cranial drape is applied in a similar manner. The side drapes are then placed, leaving a suitable area exposed for the incision. The drapes are held in position with towel forceps. The patient and the entire operating table are then covered with the main drape that has a window. The window should enclose the area of the incision. The head of the patient is left uncovered for purposes of observation during surgery.
4-Preparation of the surgeon and assistants: -
1-Members of the surgical team and operating room personnel should be appropriately clothed.
2-Observation gowns and disposable shoe covers can be worn over the usual clothes of operating room personnel and others entering the operating room.
3-Caps and masks are also necessary.
4-Cloth flaps, masks and gowns must be laundered after each use
Preparation of the hands:
1-Before preparation of the hands for sterile surgery, the fingernails are cut short.
2-The cap and mask should be worn before scrubbing commences.
3-A deep sink with facilities that permit the adjustment of water flow without touching the faucet is very useful (a knee or foot control is preferred). Warm water should be used for scrubbing. The surgical scrubbing agents of preference are povidone-iodine and hexachlorophene. The hands and forearms are washed for 30 to 60 seconds with the surgical scrub. The hands are then scrubbed with a sterile brush with stiff bristles, scrubbing agent and water. Each surface of each finger should be scrubbed as well as the surface of the hands and arms with special attention to the nails and between the fingers. The process is repeated on the opposite arm. Scrubbing should be not less than 5 minutes. Both arms are then rinsed with the hands still held above the elbows. The application of alcohol 70 % to the hands and forearms following scrubbing is preferred, then drying of the hands and arms by means of sterile towel.
Gowning and Gloving:
The sterile gown and towel wrap or drums are opened by an assistant. The gown is lifted from the sterile wrap and held away from the table. The surgeon unfolds the gown by placing his hands in the appropriate armholes. The arms are pushed in the sleeves to the cuff. An assistant closes the neck and ties the inside waist tie. The gloves are worn and folded over the cuffs of the sleeves. Some operations need rigid aseptic precautions so that two pairs of gloves should be worn.
The instruments:
Instrument trays are presented, with the assistant carefully removing the paper wrap or cover. The surgeon places the instruments on the sterile wrapped instrument stand.
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