Sterilisation and Disinfection Flashcards
What is disinfection?
A physicla/cemical destruction of microorganisms.
What is an antiseptic?
Disinfectants designed for use on the skin
Disinfection - Considerations
- Read COSHH data sheet
-The enviroment should be thoroughly cleaned to remove gross debris prior to disinfection
- use correct solution / dilution
What is sterilisation?
The removal of pathogenic micro-organism including the spore forming bacteria
What are the chemical (cold) types of sterilisation?
- Glutaraldehyde
- Irradiation
-Chemical
What are physical (heat) types of sterilisation?
- Dry - hot air oven
-Moist - autoclave
What are the 3 types of hot air ovens?
- Basic dry heat oven
- Convection oven
- High vacuum assisted oven
Hot air oven advantages
Ideal for:
- Glassware
- Drill bits
- Powder
- Oil
Hot air ovens disadvantages
- Restricted as many articles wont withstand high temps e.g:
- fabrics
- rubber
- plastics
What is a principle of moist sterilisation?
Achieve complete destruction of micro-organisms using a combination of moisture, heat and pressure
What are the types of autoclaves?
- upward displacement autoclave
-Downward displacement autoclave
-Vacuum assisted autoclave
What are some risk factors of autoclave?
- Capable of explosion
- capable of implosion
- Subject to regular testing
What materials can not be autoclaved?
- Endoscopes
-Plastics - Powder and oils
What is chemical (cold) sterilisation?
Involves submerging items in a liquid for a length of time
Solutions used are glutaraldehyde, chlorhexidine or alcohol based
What is gas sterilisation?
Effective method os sterilising equipment with good penetrative abilities
What gas is used with gas steruilisation?
Ethylene Oxide
What are the safety concerns with gas sterilisation?
Toxic
Irritant to tissue
very inflamable
Factors that influence sterility for ethylene oxide?
Temperature
Concentration
Pressure
Humidity
What are the benefits of gas sterilisation?
- Gentle (sharps are not blunted)
- Effective, even on small complex devices and tubing
Packaging and preparation for gas sterilisation
- Items placed in polythene liner
- Glass vial is placed within package
-Probe placed in bag
- Air purged from bag
What are dosimeter strips?
Undergo a colour change when exposed to ethylene oxide for correct time
What are indicator tape?
It turns yellow to red
What are spore strips?
Placed into the load, incubate for 72hours
Indicator stickers
Yellow dots that turn blue
What are steri-dot discs
Red to green
Autoclave Temp, pressure and times
221 degrees - 15 psi - 15 mins
126 degrees - 20 psi - 10 mins
134 degrees - 30 psi - 3-3.5 mins
