Surgery: Preparation and Protocols

Question 1

Define Asepsis

Answer 1

• Asepsis = absence of pathogenic microbes or infection in living tissue

Question 2

Define Antisepsis

Answer 2

• Antisepsis = use of antimicrobial chemicals on living tissue

Question 3

Define Disinfection

Answer 3

• Disinfection = destruction of pathogenic microbes, e.g.use of germicidal substances on inanimate objects

Question 4

Define Sterilization

Answer 4

• Sterilization = destruction of all microorganisms (only possible in inanimate objects)

Question 5

Describe 2 methods of hair removal

Answer 5

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

Question 6

Describe the surgical preparation for legs and paws

Answer 6

• 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)

Question 7

Give the three aims of skin prep

Answer 7

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)

Question 8

Describe clean prep using non sterile supplies

Answer 8

• 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

Question 9

Describe the surgical site preparation that occurs in theatre

Answer 9

• Patient positioned on operating table
• Final stage of prep should always be ‘no-touch’ technique with alcoholic tincture
• Allow alcohol solutions to dry completely

Question 10

Describe the action of Povidone Iodine (including what it acts on etc)

Answer 10

• 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

Question 11

Describe the disadvantages of povidone iodine

Answer 11

• 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

Question 12

Describe the disinfectant that could be used on the eyes

Answer 12

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

Question 13

Describe the disinfectant that could be used around ears

Answer 13

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

Question 14

What is contraindicated for use in cleaning the ear canal and why?

Answer 14

Don’t use chlorhexidine gluconate - causes neurosensory deafness

Question 15

Describe the action of Chlorhexidine Gluconate

Answer 15

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

Question 16

Where can chlorohexidine glutonate be useful?

Answer 16

• 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

Question 17

Where is chlorohexidine gluconate contraindicated?

Answer 17

• ototoxic: middle or inner ear deafness
• neurotoxic: avoid brain and meninges
• concs ≥0.05% toxic to cornea and conjunctiva

Question 18

Describe the action of alcohol

Answer 18

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

Question 19

What are the disadvantages of alcohol

Answer 19

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!

Question 20

Describe how you can reduce the infection rates in open wounds

Answer 20

• 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

Question 21

Describe the benefit of scrubbing

Answer 21

• Kills transient bacteria and produces prolonged depressant effect on resident bacteria

Question 22

Describe the scrubbing process

Answer 22

• 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

Question 23

Describe the compositiion and action of sterilium

Answer 23

Propan-2-ol, propan-1-ol with glycerol
• kills ≥ 99.9% of pathogens within 15 seconds
• bactericidal, yeasticidal, tuberculocidal, mycobactericidal and virucidal

Question 24

Describe the towel protocol and common mistakes that are made with it.

Answer 24

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

Question 25

Describing draping protocol

Answer 25

• 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

Question 26

Describe the benefits of double gloving

Answer 26

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

Question 27

Describe the types of drapes available

Answer 27

• 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

Question 28

Describe the sterile field

Answer 28

• Surgical site + Instrument trolley + Surgeon
o chest to level of sterile field
o sleeves from cuff to 5cm above elbow