Chapter 10 Flashcards
Disinfection and Sterilization
Disinfection is achieved by either chemical or heat means.
The highest level of contamination control is sterilization because it results in the total destruction of all forms of microbial life.
Disinfection is a less lethal process than sterilization, which kills disease causing micro-organisms. This does not include the destruction of resistant bacterial spores.
***The four most commonly used chemical agents, glutaraldehyde and chlorine dioxide based solutions, iodophors, and phenolics.
Iodophors are classified as intermediate-level disinfectants or can be used as antiseptics if the product label claims tuberculocidal (lethal to mycobacterium tuberculosis) activity.
Glutaraldehydes of 2 to 3.2 percent are FDA-registered.
Chlorine dioxide has a rapid action of 3 minutes for disinfection or 6 hours for sterilization.
generate sound waves. When the sound waves travel through the liquid, millions of tiny bubbles form and burst continuously. This process is called a “cavitation” effect.
Limit ultrasonic cleaning time to 5 minutes to avoid damage to instruments.
Do not place surgical knife blades or suture materials inside linen packs or on instrument trays before sterilization.
Heat sealed overwrapping will extend a 30 day shelf life to 180 days.
Opening all hinged instruments during packaging to allow steam to penetrate these areas
Wrapping loosely to allow steam to circulate freely throughout the pack
***The uses of muslin wraps are discouraged.
***Freshly sterilized items are never placed on metal or cold surfaces. Packages become damp from the condensation that occurs and become contaminated.
***Wrapping Method: 365 days- paprer envelope, nonwoven blue wrap with plastic covered, heat sealed or self sealed. 30 days- nonwoven blue wrap, parchment paper or Dennison wrap. INDEFINITE- Glass test tubes with screw caps
***Steam under pressure (autoclave) is the most dependable and economical method of sterilization. It is the method of choice for metalware, glassware, most rubber goods, and dry goods.
***Two of the most common types of steam sterilizers used in the Navy are the downward displacement (gravity) and pre-vacuum, high-temperature sterilizers.
The actual timing does not begin until the temperature is above 245°F (118°C).
***At 15 pounds per square inch (psi), the boiling point increases to 121°C (250°F), a temperature at which all known organisms are killed.
The following are some practical sterilization time periods. 250°F (121°C): 30 Min 273°F (134°C): 10 Min
Wrapped, covered, opened instruments placed in perforated trays are “flash” sterilized for 3 minutes at 270°F (132°C). Sterilization timing begins when the above temperature is reached, not before.
Full heating of the loads is faster in the prevacuum sterilizer than in the gravity displacement sterilizer
The Bowie-Dick type test was developed for prevacuum sterilizers to determine if the air has been removed from the chamber during the prevacuum stage.
Do not use wire brushes, steel wool, or any type of abrasive cleaning compounds on the sterilizer.
A typical dry heat cycle is 90 minutes at 320-345°F, plus the time required to preheat the chamber before beginning the sterilization cycle. Biological monitoring will be performed weekly
Chemical vapor sterilization is not routinely used in Navy dentistry.
Biological Indicator Test: A biological test pack will be placed on top of an instrument set and placed on the bottom shelf to the rear of the chamber with each load -the completion of the cycle, the test pack will be removed -to include the use of Bacillus Subtilis var. niger biological control
- After 48 hours, the results will be documented
- Sterrad sterilization records are stored for 36 months
