Cleaning Flashcards
define cleaning
Process of physically removing foreign materials from an object without destruction. e.g. mechanical (washing) or detergents -soap
define disinfection..
process of removing all pathogens from an object except bacterial spores.
usually uses chemicals such as alcohol 70% or chlorhexidine 0.5-5%
define sterilisation..
process of removing pathogens including bacterial spores from objects.
may be physical or chemical e.g. autoclaving or ethylene oxide
define decontamination
proces of removing, inactivating or destroying pathogens such that they are unable to reach site in sufficient quantities.
starts with cleaning, followed by disinfection or sterilisation
why is it important to clean before sterilising?
thorough cleaning before is important to improve efficiency of sterilisation/ disinfection.
what do these symbols mean?
A = single use
B= expiry date
C = do not use if packaging damaged
D = batch number
E = date of manufacture
what should be checked before using equiptment
expiry date
and packaging to check all sealed and not opened before
what is the SAL value
sterility assurance value
a value given to represent the probability that a device remains contaminated after it has gone through the sterilisation process
in theatre for sterile devices, we aim for SAL 10^-6 i.e. 1 in a million chance of organisms surviving
what are the categories of instruments based on the degree of infection risk?
critical - in contact with sterile tisue e.g. cannulas, catheters, surgical instruments
semi-critical - incontact with mucus membranes - laryngoscopes
non-critical - contact with skin - BP cuff
what is meant by anti-septic
a substance that is anti-microbial
may be bacteriostatic or cidal
what are the methods of sterilisation?
physical, chemical or radiation
PHYSICAL:
* steam sterilisation / autoclaving
* dry hot air - like an oven, not used in medicine
CHEMICAL
* ethylene oxide
RADIATION
* gamma radiation
tell me about autoclaving?
main method for sterilising srugical equiptment
quiptment is placed into a chamber (autoclave) and exposed to steam at specific temp for specifc time and pressure
e.g. 4mins at 135 degrees at 200kpa
it is non toxic, relatively cheap and penetrates packaging
However there is potential for burns and it is not good for heat liable items
what are the pros and cons of using ethylene oxide?
very effective and dont need heat, penetrates plastics
however potential chemical hazard to staff and slower and more expensive than autoclaving
what does the efficacy of sterilisation depend on?
if it has been cleaned first
type of microbial contamination
method of sterilisation
time exposed to steriliser
material of the object
how are sterilised items stored?
well ventilated areas protected from moisture , dust and extremes of temp
in packaging that is not compromised.
what do these symbols mean?
A - sterilised using ethylene oxide
B - sterilised using gamma radiation
C- sterilised using autoclaving, dry steam.
