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ASEPTIC & ANTISEPIC TECHNIQUES. Begashaw M (MD). DEFINITIONS. Aseptic technique : prevention of microbial contamination of tissues & sterile materials by excluding, removing or killing microorganisms
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ASEPTIC & ANTISEPIC TECHNIQUES Begashaw M (MD)
DEFINITIONS • Aseptic technique: prevention of microbial contamination of tissues & sterilematerials by excluding, removing or killing microorganisms • Disinfection: killing or removal of sufficient microbes to render an inanimateobject safe for its intended purpose • Antiseptics: Chemicals which can be applied to living tissues to kill or inhibit the growth ofmicrobes
CHOICE OF ANTISEPTIC • Ideal antiseptic: a. spectrum of activity broad b. resistant to inactivation by organic materialsblood& feces c. no toxicity or allergic reaction, non –staining d. inexpensive
Source of infection • patient • Staff • operation room • instruments
Route of infection Personal contact Airborne
Preventative Measures-patient • Short hospital stay preoperatively • Shower a day before surgery • Treatment of any infectious site before surgery • Aseptic methods • Special preparations - bowelpreparation for colonic surgery • use of antiseptic solution • Prophylactic antibiotics
Operating Theater • Staff • Wear clean clothes, shoes or covers, mask & cap • Scrubbing for at least 5 min • dry with sterile towel & apply 70% alcohol • Put on sterile gloves & gowns
Patient • Clean the operation field with antiseptic - Chlorohexidine&2.5% Iodine for adults - 70% alcohol for children • Povidone Iodine for all ages if available • cover with sterile drapes
Operating Room number of personnel reduced adequate ventilation windows should be open to allow ingress of fresh outside air &escape of anestheticgases Keep all doors closed except as needed for passage of equipment &personnel Clean operating rooms between operations
Instruments • Sterilization: - is a process by which inanimate objects are made free of all microorganisms
Decontaminate Clean High-Level Disinfect: Boil Steam Chemical Aseptic Instrument Processing Instrument Processing Dry/Cool and Store Sterilize: Chemical High-pressure steam Dry heat
Autoclaving • preferred method • uses steam at a pressure of 750mmHg above atmospheric pressure &temperature of 120 degree Celcius for 15-30mins • steam is helpful for penetration even into spores • Appropriateindicators needed
Dry heat poor alternative suitable for metal instruments uses a temperature of 170 degree celciusfor 2 hrs
Alcohols ethyl, isopropyl Acts by denaturing proteins Broad spectrum-gram-positive & gram-negative rapid action short acting moderately expensive most active against bacteria at 70% concentration Is bactericidal Also fungicidal & virucidal
Chlorhexidine Good activity against staphylococci &streptococci moderate activity against gram negative bacteria persistent action-up to 6 hrs moderately expensive non-toxic unpleasant taste
Iodine Lugol’ssolution Broad spectrum Cheap Stains Hypersensitive
Povidone iodine Broad spectrum -spore forming organisms -both gram-positive &gram-negative moderately expensive some hypersensitivity skin rapid inactivation byblood