Preparation for sterilization
All instruments must be double wrapped in linen or special paper or placed in a special metal box equipped with a filter before sterilization.
'Flashing' is when an instrument is autoclaved unwrapped for a shorter period of time. 'Flashing' is often used when a critical instrument is dropped.
Color Change Sterilization Indicators
The white stripes on the tape change to black when the appropriate conditions (temperature) have been met.
Indicators should be on the inside and outside of equipment pack.
Expiration dates should be printed on all equipment packs.
Color indicators are also included on the outside and inside of equipment sterilized in paper packages.
Biological sterilization indicators contain spores that are supplied in closed containers and are included with the instrument being autoclaved. Inability to culture the spores after autoclaving confirms adequate sterilization. Biological indicators are the most accurate sterilization indicators.
Ethylene Oxide Sterilization: ETO Gas
Large Two-Chamber EtO Sterilizer
Colorless gas, very toxic and flammable.
Requires special equipment
Odor similar to ether.
Used for heat sensitive instruments: plastics, suture material, lenses and finely sharpened instruments.
Materials must be well aerated after sterilization.
Materials/instruments must be dry.
This specific type of EtO sterilizer is only found in larger veterinary hospitals
Compact One-Chamber EtO Sterilizer
Anprolene® is the most commonly used EtO sterilizer in veterinary practices
Cartridges release 100% pure ethylene oxide
Kills all known viruses,bacteria (including spores), and fungi
Annual safety inspections are recommended
For more information on the Anprolene® system, go to the commercial vendors section
Cold (Chemical) Sterilization:
Instruments must be dry before immersion.
Glutaraldehyde (Cidex) is the most common disinfectant.
3 hours exposure time is needed to destroy spores.
Glutaraldehyde is bactericidal, fungicidal, viricidal, and sporicidal.
Radiation Sterilization:
High energy ionizing radiation destroys microorganisms and is used to sterilize prepacked surgical equipment.
Used for instruments that can't be sterilized by heat or chemicals.
Radiation sterilization is being promoted as an alternative to ETO sterilization.
Care needs to be taken because not all materials can be irradiated successfully
Currently used by manufacturers, but not used in veterinary hospitals
Common sources of radiation include electron beam and Cobalt-60
For more information on specific sterilizers which utilize radiation, go to the commercial vendors section
Filter Sterilization:
Filters are used for removal of microorganisms in fluids and gases. They come in a wide variety of types and sizes.
A 0.2 micron filter is required to remove bacteria from fluids.
The filter is placed in the IV line or on a syringe, so that the contaminated solution is sterilized before reaching the patient.
