1. Aseptic technique and Sterilization Methods CTVT pgs 1158-1168
Objectives:
Understand aseptic technique and it’s importance in surgery.
Learn how to properly sterilize instruments and equipment.

2. Asepsis- condition of sterility where no living organisms are present
Aseptic technique- all steps taken to prevent contamination of surgical site by infectious agents
Goal: to “maintain asepsis“ and watch for “breaks” in aseptic technique

3. Where do contaminants come from?
Exogenous sources:
You, patient’s fur/skin, instruments, air
Endogenous:
Inside the patient  reach the incision through blood stream

4. Ways to Maintain Aseptic Technique
Disinfection - destruction of pathogens on inanimate objects (Kennel Care, Accel)
Doesn’t effect bacteria spores
Sanitization - acceptable level of contaminants present
Antiseptic – inhibits growth of infectious agents on living tissue (Chlorhexidine)
Sterilization - complete destruction or elimination of all living organisms
Including viruses and bacterial spores
Always inorganic material

5. When does aseptic technique begin?
It’s always happening!
Cleaning of instruments
Surgery suite sanitation/disinfection
Patient prep
Sx team scrub
Surgical suite etiquette
Contamination cannot always be avoided
Skin abscess, dental disease

6. Contamination Risk of contamination doubles every hour under Ax
Contamination does not mean infection
Infection is dependent on:
Patient health
Tissue damage
Virulence and quantity of agent
The level of contamination determines:
Use of perioperative antimicrobials
Degree of asepsis required

7. Classification of Surgical Procedures
Clean = non-contaminated, routine, placement of hardware
Ex. permanent implants (IM pins), benign laparotomy
Clean-contaminated = entering a hollow organ
Ex. enterotomy, cystotomy
Contaminated = leakage during Sx or major breach of aseptic technique
Dirty = previously ruptured hollow organ or abscess
Ex. cutaneous abscess, septic peritonitis, ruptured pyo

8. Methods of Sterilization
Physical Sterilization
Filtration
Radiation
Heat
2. Chemical Sterilization
Liquid
Gas

9. Filtration Sterilization
Filtration – microorganisms separated from liquid materials
Pharmaceuticals
Can be placed on IV line or syringe

10. Radiation Sterilization
Radiation - destruction of microorganism without significant increase in temperature
Gloves and suture material
*Filtration and radiation are typically performed by the manufacturer before shipments
- anything that comes pre-sterilized
- a lot of “one time use” products
- items which cannot be heat sterilized

11. Heat Sterilization Most common sterilization technique
Destroys bacteria by denaturing their proteins
1. Dry Heat Sterilization
High temperatures for a long period of time
2. Wet Heat Sterilization
Creating steam under pressure at high temperatures
Ex. Autoclave

12. Dry Heat Sterilization
Does not involve moisture (no rust, no corrosion)
Takes longer than wet heat and requires higher temperatures
(no steam to achieve the higher temperature)
Ex. 300°f for 2 ½ hours

13. Wet Heat: Autoclave Sterilization
Pack must be able to withstand
heat AND moisture!
Pre-vacuum sterilizer
A pump evacuates the air before the steam enters
More even penetration of steam
Shorter duration
Gravity Displacement Sterilizer
Steam enters the top and forces air to bottom
Most commonly used type

14. Autoclave Sterilization (Gravity Displacement)
Used most commonly for “packs”
Heat = 250 °F minimum
Pressure = 20 PSI
Time = 13 minutes at temp (exposure time)
Total cycle =Heat-up + exposure + dry time
Usually minute cycle
Always use distilled water!
*Every machine is different, refer to the operator's manual
(usually have pre-set buttons to use)

15. There should be space between each pack!
Steam should be allowed to flow around every surface of each pack
Use multiple racks if sterilizing a lot of packs

16. Pack Preparation Proper pack preparation is critical
Instruments must be clean and dry
All locking instruments should be unlocked
Wrap materials must be steam permeable
1. Woven = double thickness muslin
Reusable
2. Non-woven =crepe paper or plastic pouch
One time use …(mostly)
Many practices double wrap (AAHA)

17. Pouch Preparation Peel packs – clear plastic pouches
made of plastic and paper
Self-sealing or heat sealed
Instrument is placed into pouch with
the handles toward the closed in
Plastic side should face down
Pack will be opened from the closed end

18. Labeling of Packs Three requirements: What is in it
Initials of who prepared it
Date it was sterilized
*VTI- which patient it is for

19. Sterility Indicators 1. Tape – outside of pack was exposed to steam
2. Chemical Indicator Strips- change color when exposed to steam for adequate time
Examples:
Peel packs – indicator on the outside of the paper
OK Strip - can be placed in the center of the pack
Stickers- can be placed anywhere (mostly for gas)

20. Sterility Indicators
3. Pellet glass – glass ampule containing a temperature sensitive pellet that melts between °F
4. Biological/Culture tests – contain a spore population of bacteria (usually Bacillus sp.)
Takes minimum of 24 hours for results
Confirms that microorganisms
were in fact killed if the sample does
not grow anything

21. Autoclave Quality Control
Performed by technicians- ensures proper technique
Sterility Indicators
Must be used in combination, as not just one will cover all requirements
Temperature graphs
Autoclave maintenance - autoclave cleaner
Ex. Speed-Clean – mixed in the water
Ex. Chamber Brite – powder is sprinkled on the bottom of cold chamber; cycle is ran without drying
Both require a “rinse” cycle to be ran after use

22. After the Autoclave Cycle
Packs must cool slowly to prevent condensation which could:
Wick bacteria
Rust metal
Tear paper
Let the dry cycle finish completely!
Door should be cracked to vent slowly ~ minutes
Opening door wide causes steam to condense inside
the pack becomes wet wicks bacteria
Don’t leave paper packs in autoclave longer than needed (makes paper more brittle, easy to tear)

23. Maintaining Sterile Packs
The outside is not sterile
Storage: dust free, dry, well-ventilated, away from contaminated areas - closed cabinet is safer than open
Broken sterility: dropped on floor, wet, broken outer wrap (instruments penetrates paper)
Never assume sterility - autoclave again
Error on the side of caution
Monitor dates for expired sterility
(clinic protocol)

24. Length of Sterility Table on page 1163 in CTVT
1. Date related practice: Which one lasts longer?
Double vs. single wrapped
Non-woven vs. Woven
Closed vs. open cabinet
Heat sealed vs. Self-sealed
2. Event related practice: item is sterile until an event in which the sterility is broken

25. Flash Sterilization (Emergency situation)
Instruments are placed unwrapped in a perforated metal tray
270°F for 3 minute exposure time
Removed with detachable metal handles and carried straight to surgery (or huck towel)
Instruments must cool before use
Some machines have a preset for this