HCAI 2 - Prevention Flashcards
Aseptic technique
Practices and procedures performed under controlled conditions, aimed at limiting the spread of potential pathogens
Function of protein A in C. dificile
Inhibits phagocytosis
Why do IV lines have to be moved every 1 or 2 days?
This prevents bacterial colonisation
Positive pressure rooms
Room has a higher pressure than surrounding rooms
Used when patient is severely immunocompromised
Organisms can’t enter the room in the air
Negative pressure rooms
Room has a lower pressure than surrounding rooms
Used when patient is extremely infectious, airborne spread
Mask that can protect against airborne viral transmission
Submicron particulate mask
ESBL
Extended-spectrum beta lactamase
Disinfection
Removing an article of some or all of its burden of microorganisms
Sterilisation
Destruction or removal of all microorganisms, spores and other infectious agents from an article
Methods of disinfection
Hot water/steam
Washing/cleaning
Chemical disinfectants
Examples of chemical disinfectants
Hypochorite (bleach)
Alcohols
Chlorhexidine
Phenols
Sterility assurance
A probability that a microorganism will survive a sterilisation process
Will render a proportion of sterilised articles unsterile
Units used to measure sterility assurance
Log10 of organisms
Determining contamination of an article
Perform a viable count
Prepare dilutions of a sample
Spread on agar plates, incubate
Count colonies
Killing rate curve
Determine initial viable count
Expose to agent
Repeated viable counts
Calculate Dx time
Dx value
Decimal reduction time
Time to reduce a particular population ten-fold at a particular temperature (90% reduction)
Sterilisation cycles 1) 2) 3) 4) 5)
1) Preparation time
2) Penetration time
3) Holding time
4) Safety margin
5) Cool down/drying/aerating
Sterilisation time
Penetrating time+holding time
Penetration time
Time for pack temperature to rise to chamber temperature
Moist heat mechanism of killing
Coagulation
Dry heat mechanism of killing
Oxidation
Most effective kind of heat sterilisation
Moist heat under pressure
Upon condensation, moist heat:
Liberates intense latent heat
Contracts in volume (drawing in more steam)
Pros of moist heat
Uses lower temperature
Shorter time needed
