Aseptic Technique

Aseptic Technique

1. Asepsis

   • Removal of pathogenic micro-organisms
     • e.g. bacteria, viruses, fungi, parasites
   • Protecting against infection from pathogens
   • Systematic removal of sources of contamination
     • Not aiming for complete sterility
       • Just causes of disease

2. 1. Operating Theatre

   • Minimal traffic through theatre
     • One way flow
     • Limit no. of doors
   • Surgical attire for all who enter
     • Scrubs
     • Designated boots
     • Head cover
     • Mask
   • Clean and disinfect regularly
     • Suitable drainage
     • Only essential and easily movable furniture present
   • Air under mild pressure
     • Air flows out not in
   • Ideally 2 separate theatres
     • Otherwise, clean before contaminated surgeries

3. 2. Patient Preparation

   • Skin preparation
     • Hair removal
       • Clipping, not saving
       • Preferably outside theatre
       • Pre-induction
       • 10-15cm away from intended site
         • Can incise further if the need arises mid surgery
     • Cover feet (+ tails)
     • Clean skin
       • Scrub solution
         • Gross prep
         • Until clean
         • Rinse in between
         • Rub white swab over at end
           • No traces of dirt
         • Plenty of water
       • Gloved hands
     • Disinfect skin
       • Gloved hands
       • Scrub solution + water
       • Start at site
         • Work outwards
         • 5 mins
     • Final disinfectant
       • Left in place
   • Antiseptics
     • Clorhexidine
       • Low residual activity
         • Binds to protein in skin
         • Lasts longer (~3 hrs)
       • Low toxicity
         • Can be toxic to fibroblasts
         • Remember in older wounds
     • Iodine compounds
       • Stains, radioopaque, smells
       • Only free iodine is bactericidal
       • Providone iodine
         • Releases free iodine when diluted with detergent
           • Sets a cascade which releases iodine
       • Low toxicity
       • Inactivated in presence of organic debris
         • Patient must be completely clean before use
       • Synergistic effect with alcohol
     • Alcohol
       • Only effective against bacteria
       • Inactivated in presence of organic debris
       • No residual activity
         • Evaporates
       • Commonly used as a rinse after surgical scrub
         • Gets rid of soap scum
   • Draping
     • Aim to prevent movement of debris and bacteria from non-sterile areas to surgical site
     • Impermeable, disposable drapes are best
     • Drape from clean to dirty
       • Keep hands on sterile part of drape
     • Double gloves
       • Reduce contamination
       • Remove one pair pre-incision
     • Use additional drapes if concerned about contamination mid surgery
     • Towel clamps to fix in place
       • If removed - tips are not sterile

4. 3. Surgeon's Preparation

   • Clothing
     • Scrubs
     • Cap
     • Designated footwear
     • Applies to all theatre personnel
   • Hand disinfection
     • Scrubbing
     • Remove gross contamination and reduce bacterial count on skin
       • Ideally a prolonged effect
     • Follow protocol
       • 1. Wash hands and forearms with water and soap Clean finger nails
       • 2. Use surgical scrub brush to wash with antiseptic soap (povidone iodine or chlorhexidine gluconate). Chlorhexidine is superior because of it’s prolonged residual activity. Contact time is important, so soap should be applied on hands and forearms before continuation with through scrub.
       • 3. Make sure to include front and back of hands, four sides of each finger and thumb, fingertips, finger nails, between each finger, wrists and forearms. Repeat twice with rinsing after each time.
       • 4. Keep hands above elbows at all times to avoid contaminated water from elbow running back down on forearms and hands.
       • 5. Total scrub time 3-5 mins
       • 6. Dry with sterile towels. Dry hands first, then dry forearms from wrist to elbow (not back up) and then discard towel. Use second towel for other hand and forearm.
   • Alcohol based hand rubs
     • Just as/even more effective
     • Long duration of action
     • Thorough pre washing required
       • Removal of gross contamination
   • Gloving and gowning
     • Never touch outside surface
     • Gowns
       • Folded inside out in sterile packing. Find and hold the neck of the gown with one hand, place both hands in arm holes and shake out gown. An assistant will tie up gown behind you. Pull card of short tie and give to assistant, turn around, grap tie from assistant (do NOT touch the card) and tie knot. Gowns should be water resistant, comfortable and breathable
     • Gloves
       • Closed gloving preferable
         • Fingers do not leave gown until covered with glove
           • Decrease contamination

5. 5. Surgical Instruments

   • Cleaning
     • Rinse immediately after use
     • Disassemble complex instruments
     • Manual cleaning
       • Warm soapy water
     • Ezymatic detergent
     • Ultrasonic cleaner
       • High frequency vibratory waves
       • Clean through cavitation
     • Post cleaning place in instrument milk (oil)
       • Lubricates
       • Protects surface
   • Packing
     • Markings
       • Date
       • Content
       • Person responsible
     • Store for appropriate time
       • Material and packing method dependent
     • Crepe preferable to cotton or muslin
       • More durable
     • Aluminium composite containers
       • Dent resistant
       • Easy to store
     • Single instruments
       • Paper on one side
       • Cellophane on the other
       • Ends are heat sealed
       • Double wrapping recommended
   • Sterilisation
     • Heat
     • Chemical

6. 5. Prophylactic antimicrobials

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