3 – Aseptic Principles and Technique Flashcards
1
Q
Surgical site infection
A
- Infection involving a surgical site within 30 days of surgery (1 year if implants are involved)
- Account for 1/3 of infections acquired in hospitals
- Superficial: skin, SQ
- Deep: fascia, muscle, body cavity
2
Q
Why are surgical site infections bad?
A
- Patient morbidity or mortality
- Increased costs
- Angry clients with suspicions about the surgeons’ competence
3
Q
History of surgeons
A
- Used to be very dirty
- Semmelweis: made doctors wash their hands
- Then rubber cloves (publicly available in 1964)
4
Q
Antisepsis
A
- Killing of microorganisms
5
Q
Asepsis
A
- Avoiding introduction of microorganisms
6
Q
Sterility
A
- Complete absence of all microorganisms
7
Q
Surgically clean
A
- All accessible microorganisms on surface have been removed and clean
8
Q
Clean surgery
A
- Body part is entered using aseptic technique and has few microorganisms present
9
Q
Contaminated surgery
A
- Microorganisms are present (>million/square cm)
10
Q
Dirty surgery
A
- Microorganisms and other foreign materials are present
- Ex. removing an anal sac
11
Q
Infected
A
- Microorganisms multiplying and generally producing a reaction in the patient
12
Q
What are the sources of microorganisms?
A
- Environment
- Equipment
- Patient
- Surgical team
- Surgical site
13
Q
What are some environmental factors?
A
- Hospital design or protocols
o Room=positive air pressure - Cleanliness or protocols
- Traffic
- Number of people or talking
- *use of antibiotics
14
Q
What are some different ways to sterilize equipment?
A
- Steam
- Gas (ethylene oxide)
- Plasma (H2O2)
- Ionizing radiation
- Cold chemical
15
Q
Steam sterilization
A
- Autoclave
- Uses steam under pressure for specific time
o 121 degrees C for 15-30mins - Requires
o Clean instruments
o Correct packing and wrapping
o Proper positioning in unit - Special certificate program
16
Q
How do we know if the steam sterilization worked?
A
- Chemical indicators
o Autoclave tape: outside the pack (black stripes)
o Indicator strips: inside the pack
o ALWAYS USE BOTH - Biological indicators
o Non-pathogenic heat resistant spores (Bacillus spp.)
o Bacterial growth=entire load NOT sterile
17
Q
Cold chemical sterilization: glutaraldehyde
A
- Used for some equipment sensitive to heat
- Can only be used on instruments that can be submerged in water
- Regular bacteria killed within 10 mins, but 10-12 hrs to kill spores
- *irritating=must RINSE well
- Respiratory and dermal irritant
18
Q
Prophylactic antibiotics
A
- Used to prevent infection rather than to treat it
- *first generation cephalosporins
o Staph and Enterobacter: dogs (+Pasteurella in cats)
o Staph, Strep, E.coli: horses - Want high tissue levels at time of skin incision
o IV is best (give 30-60mins before surgery begins)
o Some studies: if continue for more than 24hrs after surgery=can increase likelihood of antibiotic resistance and infection
19
Q
Which operations are prophylactic antibiotics appropriate for?
A
- Significant RISK of infection (contaminated or dirty operations)
- Long surgeries (>90mins)
- When large implants placed
- When infection would be catastrophic
20
Q
Hair removal
A
- Remove gross contaminants first
- Tense skin while clipping
- Clip, DON’T SHAVE (#40 blades recommended)
- Do clipping after anesthesia is induced: 3-10x higher infection rate if done earlier
21
Q
Why do skin preparation?
A
- Remove dirt
- Eliminate transient bacterial flora
- Reduce resident microbial count
- Inhibit rapid rebound growth of microbes
22
Q
Skin preparation: antiseptics
A
- Chlorhexidine followed by alcohol is more effective than povidone iodine (but use it still for eyes and prepuce area)
- Chlorhexidine binds to keratin=prolonged residual activity
o Still ~20% flora present in hair follicles - Contact time is important
o Follow manufacturer’s recommendation
o Minimum of 3min contact time
23
Q
Skin preparation: technique
A
- Sterile prep: use sterile gloves
- Use dominant hand to prep, other hand to pick up gauze
- Circular pattern: from incision site to periphery
- Do NOT go back to incision stie with same sponge
- Don’t scrub too hard
24
Q
Protecting the surgical site
A
- Drapes: barrier to prevent spread of microbes from patient’s skin/hair into incision
o Cloth: needs special treatment to make it waterproof
Thread count important
If water can go through=so can bacteria
Waterproof coating
o Disposable
Synthetic polymers
Also need special treatment to be waterproof
25
Q
Surgical draping: technique
A
- Initial layer: use 4 quarter drapes around the prepped area
- Fold drape edges (makes 2 layers) for extra protection right around wound (and protects fingers when placing it)
- Secure with towel clamps
- Final drape: single large drape to cover entire patient and table
26
Q
What do you NO do with surgical draping?
A
- Readjust drapes once placed (towards the incision)
- Reuse towel clamps once they’ve penetrated skin
- Use a penetrating towel clamp to secure the final drape
o Can use NON-penetrating clamps, but not to the patient
27
Q
Surgeon preparation
A
- Minimize contamination of incision by surgeon
- Surgical scrubs
- Surgical caps
- Mask: use new one for each surgery
- Shoe covers/booties OR dedicated shoes
28
Q
Surgical hand scrub
A
- With antiseptic soap/sponge (under nails!)
- Ethyl alcohol based rub solution (ex. Sterillium) for waterless scrub technique (used in between if doing multiple surgeries)
- Short, clean nails
- No rings/jewellery
29
Q
Surgical gowns
A
- Waterproof impermeable barrier
o Cuff are NOT impermeable=cover with gloves - Wet=contaminated
- Use new gown for each surgery
- No difference in infections if use paper vs. treated cloth as long as it is waterproof
30
Q
Surgical gloves
A
- Not an absolute barrier (1.5% gloves have holes when open)
- Up to 60% incidence of glove perforation by end of surgery
o More common in non-dominant hand
o Perforation more common during orthopedic surgery (use thicker gloves or double) - Change if you notice holes or suspect you punctured the glove
31
Q
Establishing vs. maintaining sterility
A
- Constant vigilance is necessary
32
Q
What are some other factors that influence surgical site infection development?
A
- Attention to aseptic technique
- Tissue trauma
- Amount of hemorrhage
- Dead space
- Surgical time: infection rate doubles each hour of surgery
33
Q
Surgical procedure and site factor
A
- Overall infection: 5.1%
o Increases as goes from clean (4.5%), clean-contaminated, contaminated to infected (18%) - **GI and feet are more prone to infection
34
Q
What are some patient factors influencing surgical site infection development?
A
- General health
- Distant infection
- Duration of hospitalization
- Total anesthesia time (increase each hour of anesthesia)
- Hypotension and hypotension during surgery=increases chances of infection
