1
Third stage
Surgery
Lec-4
.د
زياد
1/1/2016
Sterilizations and Disinfection
Disinfection
Disinfection: is a process that kills or remove pathogenic microorganisms except spores.
Disinfectant: A chemical agent used to achieve disinfection.
The efficiency of disinfection depends on:
1- Nature and load of microorganisms.
2- Duration of exposure to the chemical material.
3- Temperature of the environment.
Methods of disinfection
1- Low temperature steam: dry steam at 73C° for 20 minutes at sub atmospheric pressure.
2- Boiling water exposure to 100C° for 5 minutes at normal pressure.
3-Formaldehyde gas exposure in specialized cabinet at 50C°.
4-Glutaraldehyde 2% effective for heat sensitive material like flexible endoscopes, but its
toxic and cause allergic reaction.
Sterilization
Sterilization: A process that destroy all form of microbial life including bacteria, virus,
fungus and spores.
Methods of sterilization:
1- autoclave: specialized container supply moist steam under pressure with high
temperature. Used for metal ware, glassware, rubber and dry goods. The temp and time
needed are: 3 minutes at (132°C), 8 minutes at (125°C), 15 minutes at (118°C).
2- Ethylene oxide: A penetrative non corrosive gas used to sterilizes heat and moist
sensitive substance.
3- Irradiation:Using gamma ray to sterilize syringes, catheters, canulas and other plastic
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tubes and heat sensitive objects.
4- Peracitec acid: chemical agent cause protein denaturation suitable for endoscopes.
Some chemicals used in skin preparation and wound cleaning:
1- Povidone iodine: Can be used to disinfect skin before operation and to clean infected
wounds and ulcers. Side effects: allergy, metabolic acidosis, interfere with thyroid function
test, not recommended in pregnancy, not used inside abdominal cavities.
2- Chlorhixidine: Effective against gram positive microorganisms. Can be used to disinfect
skin before operation and to clean infected wounds and ulcers.
3- Alcohol: 70% used as disinfectant to prepare skin for operation, not used for wound or
ulcer.
4- Hydrogen peroxide: Week disinfectant help to flush out depress from cavities by
mechanical action.
Prevention of Wound Infection
1) At patient level
1- Avoid prolonged preoperative hospital stay.
2- Control any source of infection if possible.
3- Control DM, uremia, anemia, malnutrition, electrolyte disturbance.
4-Preoperative bathing.
5-Stop smoking.
5- Avoid shaving the area of operation, if this is mandatory it should be on the table.
6- Prophylactic antibiotic.
7-Early post operative mobilization and exercise.
2) At staff level
1-Staff with focus of infection should not deal with patients.
2-Decrease number of staff in the operative theatre with less movement as possible.
3-Warring of special clothes and gowns.
4- Using the head caps, face mask and boots.
5- Hand washing.
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6- Warring sterile gloves during surgical procedure and usual gloves when dealing with
infective focus.
3) At operative theatre level
1- The operative theatre design and building.
2- The ventilation system.
3- The table and light source.
4-Anesthetic machines and equipments.
5-Suckers and electro-cauterization devices.
6- Surgical instruments.
4) At surgical word and medical devices level
1- Surgical word devices including: beds, mattresses, pillows, urinals and surgical truly.
2-Reception and examination rooms.
3- Cannula, IV set line, drains, tubes and blood transfusion sets.
4- The visitors.