Chapter 11: Sterilization Flashcards
What is the Spaulding classification regarding instruments for sterilization?
- Critical - come into contact with the bloodstream or sterile tissue (instruments, needles, catheters should be sterile)
- Semi-critical - Come into contact with mucous membranes or non-intact skin (ETT, laryngoscopes, high-level disinfection)
- Non-critical - Contact only intact skin (stethoscope, BP cuff, intermediate level disinfectants)
What is toxic anterior segment syndrome (TASS)?
Uveitis from not washing all the cleansers off ophtho instruments.
What are the main options for cleaning of surgical instruments prior to sterilization?
- Manual cleaning with enzymatic cleaners or detergents (no bubbles)
- Mechanical cleaning of surgical instruments (preferred method)
Ultasonic cleaning with cavitation, washer decontaminators, washer disinfectors and washer sterilisers. Instruments must be thoroughly rinsed after cycle is complete
What is the only approved method for drying instruments prior to sterilization?
Filtered, medical grade compressed air
What are the (9) ideal properties of a wrapping material?
- Prevent microbial penetration
- Permeable to the sterilising agent
- Resistant to heat
- Allow for aeration
- Resistant to physical damage and moisture penetration
- Possess minimal wrap memory
- Long shelf-life with sufficient strength and durability
- Free of toxic ingredients and dyes
- Provide a barrier to microorganisms and fluid
Does not exist!
What is the most common wrap material? What are its downsides?
Cotton muslin wrap
- Can generate lint
- Not moisture resistant
- Requires a double layer
List the methods available for sterilization:
- Liquid chemical germicides (cold sterilization)
- Steam sterilization
- Ethylene oxide sterilization
- Ozone sterilization
- Plasma sterilization
- Vaporized Hydrogen Peroxide
- Sterilization by radiation
List some options for cold sterilization. What are the problems with cold sterilization?
- Glutaraldehyde 1-1.5%
- Orthophthalaldehyde (Cidex)
- Hydrogen peroxide 7.5%
Should be considered high level disinfectants rather than sterilization. Glutaraldehyde is irritating to skin and can decrease pulmonary function.
How do steam sterilizers work?
Kill microorganisms through coagulation and denaturation of proteins by moist heat
- Water serves as a catalyst and allows lower temperatures to be used
What are the 2 types of steam sterilizers?
- Gravity-displacement (steam rises to the top and cool air is removed though a valve at the bottom)
- Prevacuum type - A pump is used to remove air before steam is admitted to allow for very rapid and uniform steam distribution
What are the temperature and time options for gravity-displacement autoclaves?
- 121C for 30 minutes with 15-30mins drying
- 132C for 15 minutes with 15-30mins drying
What are the potential causes of wet packs after steam sterilisation?
- Improper loading
- too large metal mass
- Overloaded tray
- Lack of absorbent materials
- Insufficient cooling time
What is the recommended temp and time for dry heat sterilisation? When is this indicated?
- 160C for 120 mins
- Certain sharp instruments, glassware and powders that can be damaged by moisture
What are the guidelines for flash sterilisation of a metallic, unwrapped, nonporous item in a gravity-displacement autoclave?
135C for 3min with 1 min drying
“immediate use steam sterilization” is for emergencies, burns can result from temperature. Not for implantable devices.
What are the safety concerns surrounding ethylene oxide?
Carcinogenic, mutagenic and neurologic hazards
