Surgery: Preparation and Protocols Flashcards
Define Asepsis
• Asepsis = absence of pathogenic microbes or infection in living tissue
Define Antisepsis
• Antisepsis = use of antimicrobial chemicals on living tissue
Define Disinfection
• Disinfection = destruction of pathogenic microbes, e.g.use of germicidal substances on inanimate objects
Define Sterilization
• Sterilization = destruction of all microorganisms (only possible in inanimate objects)
Describe 2 methods of hair removal
Depilatories - hair removal cream (can be expensive, messy and irritant)
Clipping - Best method, clip 10 -15 cm around proposed wound site and vaccum patient and table
Describe the surgical preparation for legs and paws
- Often clip entire limb for orthopaedic procedures - hanging limb prep
- Consider which limb is used for intravenous cannulation!
- Paws – lot of bacteria, and difficult to deal with nail beds and pads
- Ideally cover paw – impermeable material (e.g. surgical glove or vetwrap)
Give the three aims of skin prep
Remove gross dirt and transient microbes
2. Rapidly reduce resident microbial count to sub-pathogenic levels, with minimal tissue irritation
3. Inhibit rapid rebound growth of microbes
Skin is not made sterile – antiseptic doesn’t reach deeper layers of skin (20% bacteria there)
Describe clean prep using non sterile supplies
• Clean prep’ using non-sterile supplies
o wear gloves
o good quality swabs
o avoid cotton wool (leaves fluff)
o don’t use scrub brushes
• Use warm water, and avoid wetting the patient excessively hypothermia
• Don’t be rough trauma and increased bacterial release from hair follicles
• Gentle pressure, circular motion, from centre outwards, discard until swab clean, contact time v important
Describe the surgical site preparation that occurs in theatre
- Patient positioned on operating table
- Final stage of prep should always be ‘no-touch’ technique with alcoholic tincture
- Allow alcohol solutions to dry completely
Describe the action of Povidone Iodine (including what it acts on etc)
- Damages the cell wall, and inhibits protein synthesis
- Iodophor = iodine complexed with high mw carrier to reduce staining and local tissue toxicity
- Greater dilution paradoxical increase in bactericidal activity (10% povidone-iodine diluted to 0.1% solution has most free iodine) less concentrated = more effective
- Rapid action
- Bactericidal, broad spectrum
- Fungi, most viruses, protozoa, yeasts and mycobacteria
Describe the disadvantages of povidone iodine
- Activity decreased in presence of organic material
- Relatively high incidence of skin reactions (up to 50% animals)
- Acute contact dermatitis
- Sensitivity in people
- Systemic toxicity if used on open wounds, mm’s and peritoneal surfaces
Describe the disinfectant that could be used on the eyes
Povidone Iodine
EYES: gently flush
• 1:10 dilution around eyelids
• 1:50 dilution on ocular surfaces and conjunctival sac
Remove residual solution with sterile saline or Hartmann’s
Never use products containing detergents or soaps
Describe the disinfectant that could be used around ears
Povidone Iodine
Pinna and surrounding skin can be prepared routinely (PI + alcoholic tincture)
Ear canal: use 1:10 dilution PI to flush, no alcohol
Don’t use chlorhexidine gluconate - causes neurosensory deafness
What is contraindicated for use in cleaning the ear canal and why?
Don’t use chlorhexidine gluconate - causes neurosensory deafness
Describe the action of Chlorhexidine Gluconate
Bisbiguanide compounds: alter cell wall permeability and cause protein precipitation
• Rapid action
• Bactericidal, broad-spectrum (better against +ve’s than -ve’s)
• Effective against some resistant bacteria incl. MRSA
• Good against most yeasts
• Variable against fungi and some viruses
• Minimal effect against spores
• No effect against mycobacteria
Where can chlorohexidine glutonate be useful?
- Active in presence of organic matter
- Excellent persistent and residual activity as binds to stratum corneum – repeated applications have cumulative effect
- Skin reactions uncommon, sporadic with prolonged use (photosensitivity, contact dermatitis and hypersensitivity)
- Minimal skin absorption so OK for neonates
Where is chlorohexidine gluconate contraindicated?
- ototoxic: middle or inner ear deafness
- neurotoxic: avoid brain and meninges
- concs ≥0.05% toxic to cornea and conjunctiva
Describe the action of alcohol
Part of 2 step procedure: increases effectiveness of chlorhexidine and iodophors
Bactericidal, broad-spectrum
Good activity against bacteria and fungi, variable for viruses, poor against spores
Rapid kill, but max bactericidal activity requires 2 mins contact, best if 60-70% concentration Efficacy decreased in presence of organic matter
What are the disadvantages of alcohol
Efficacy decreased in presence of organic matter
• relatively non-toxic, except in newborns
• avoid open wounds
• skin drying, and degree of hypothermia via evaporation
• explosions and fire hazard!
Describe how you can reduce the infection rates in open wounds
• All antiseptics cause tissue damage in an open wound
• Can use chlorhexidine – at 0.05% (cf 2-4% for scrub)
• Pack wound with sterile KY jelly or intrasite
• Clip routinely
• Lavage copiously with (several litres) sterile warm Hartmann’s or saline:
dilution = solution to pollution
Describe the benefit of scrubbing
• Kills transient bacteria and produces prolonged depressant effect on resident bacteria
Describe the scrubbing process
- Prewash hands to remove gross debris
- Rinse with scrub solution (commonly chlorhexidine or povidone iodine)
- Pay particular attention to the nails, and don’t forget the thumb and ulnar surfaces
- All surfaces of hands and forearms are exposed to scrub for at least 2 min
- Often timed, with common technique being described as a 5 min scrub
- Always keep the hands above the elbows
Describe the compositiion and action of sterilium
Propan-2-ol, propan-1-ol with glycerol
• kills ≥ 99.9% of pathogens within 15 seconds
• bactericidal, yeasticidal, tuberculocidal, mycobactericidal and virucidal
Describe the towel protocol and common mistakes that are made with it.
Towel Protocol • Open towel, and keep at arms length • Consider towel in quarters • Dry hands on top quadrants • Dry arms on lower quadrants Common mistakes resulting in contamination: • Going back to hands • Towel touches front of scrubs
Describing draping protocol
- Quarter draping – standard
- Edge of drape folded and gloves kept within the corners of the folded edge
- Do not move drape once positioned
- Towel clamps break sterile barrier of drape – so used towel clamps are contaminated
- NEVER use tissue forceps to attach drapes
Describe the benefits of double gloving
Double Gloving
• May see in referral for orthopaedic surgery
• Dark coloured glove underneath, if a nick is put in upper glove fluid will enter and colour will be more visible
Describe the types of drapes available
- Cotton muslin +/- skin towels
- Disposable
- Adhesive incise drapes: clear, waterproof, but expensive, don’t stick well, and no strong evidence that they reduce infection rates
- Some come impregnated with iodine
Describe the sterile field
• Surgical site + Instrument trolley + Surgeon
o chest to level of sterile field
o sleeves from cuff to 5cm above elbow
