Disinfection Flashcards
disinfection vs sterilisation
Disinfection – A process which removes most viable organisms but does not inactivate viruses and bacterial spores
Sterilisation- Complete destruction of living organisms (including spores and viruses)
spaulding classification of level of sterilisation
Spaulding classification
Critical Instruments : Instruments that penetrate sterile tissue (surgical instruments)
Semi-critical : Contact with mucous membranes (endoscopes, laryngoscope blades)
Non-critical :items that only come into contact of intact skin (blood pressure cuffs/stethoscopes/bed rails)
critical instrument disinfection 3
sterilisation
autoclave
plasma gas
or ethylene oxide gas
sterilisation autoclav
3 components
temperature
pressure
Steam Sterilisation (Autoclave)
Sterilization in saturated steam thus requires precise control of time, temperature, and pressure is required
Temperatures of 121-134 C for up to 5-30 mins between 200-300kPa.
134 C for hold time 3 minutes
121 for 15 minutes
dry heat sterilisation
Dry-heat sterilization requires a higher temperature than moist heat and a longer exposure time. The method is, therefore, more convenient for heat-stable, non-aqueous materials that cannot be sterilized by steam because of its deleterious effects or failure to penetrate. Such materials include glassware, powders, oils, and some oil-based injectables
ionizing radiation sterilisation
Gamma radiation and electron beams are used to effect ionization of the molecules in organisms. Mutations are thus formed in the DNA and these reactions alter replication. Used for plastic syringes, catheters, gloves, sutures.
gas sterilisation
using ethylene oxide
for items sensitive to heat, pressure or moisture
semi critical
Minimal requirement therefore is high level disinfection using chemical disinfection
Should be free of all micro-organisms but small amount of bacterial spores may be present
Intact mucous membranes are resistant to infections by common bacterial spores but susceptible to bacteria, virus e.t.c
disinfection endoscope
- Connection to endoscope washer disinfector + perform leak test
- Initial Flushing of endoscope
- Checking lumen patency
- Clean and rinse
- Chemical disinfection
- Final rinse
- Drying
disinfection endoscope
- Connection to endoscope washer disinfector + perform leak test
- Initial Flushing of endoscope
- Checking lumen patency
- Clean and rinse
- Chemical disinfection i.e. chlorine dioxide, Tristel
- Final rinse
- Drying
In essence,
this involves the initial manual cleaning of the endoscope to remove any adherent
material, followed by mechanical cleaning and disinfection utilising an enzymatic
detergent and high-level disinfectant.
types of disinfectants
aldehyde - not recommended, not effective against CJD
paracetic acid
minor corrosion capacity
halogen based disinfectant
chlorine based
some potnetial corrode metal and some plastics
autmated cleaning
Automated cleaning can take place in a washer/disinfector, which goes through
a cool prewash, at below 35°C to prevent protein coagulation, a main wash, rinse,
thermal disinfection, and postdisinfection rinse, or using an ultrasonic cleaner/disinfector.
Ultrasound is used to agitate the water by creating bubbles which implode,
dislodging dirt from the surface, and joints, of surgical instruments.
disinfection washing process
Moist heat is the method of fi rst choice as it is easily controlled, leaves no toxic
residues, and is relatively safe to those involved in the process. Disinfection can be
achieved by washing or rinsing devices in water at between 73°C and 90°C as is
achieved in many automated washer/disinfectors.
flexible endoscopes cannot withstand temp
Flexible endoscopes cannot withstand processes involving temperatures in excess
of 65°C. Reprocessing of fl exible endoscopes should follow, for example, the British
Society of Gastroenterology (BSG) guidelines for decontamination of equipment
for gastrointestinal endoscopy (
skin prep solutions washing hands and patient
washing hands
povidone iodine 7.5%
chlorhexidine gluconate 4% - Hibiscrub
patient prep
iodine 10% = videne aqueous povidone iodine betadine or videne
genital chlorhexidine gluconate 0.5-2%
chlohex 2% pink solution = chlorhexidine Gluconate 2% w/v in Isopropanol 70% v/v combining immediate and sustained effect to prevent microbial re-growth
chloraprep same thing, on sponge, can be tinted
meatal cleaning
trials no advantage antibacterial vs not
australian trial superiority 0.1% chlorhex Hexicath
