sterilisation and infection prevention Flashcards
what are the 3 main types of transmission of organisms
contact (direct and indirect)
airborne
droplet
which pathogens can be transferred from direct person to person contact
scabies
HSV
what is the difference between droplet and airborne pathogens
- droplet >5microns - drop to the ground by ~1m
- airborne <5microns - stay in the air
which pathogens are considered to be spread by droplets
influenza pertussis SARS neisseria m. rhinovirus
which pathogens are considered to be spread by the airborne route of transmission
TB
measles
varicella
measles
what are the 4 types of isolation precautions
standard precautions
contact precautions
droplet precautions
airborne precautions
when are standard precautions used
used for all patients at all times regardless of patient diagnosis or presumed infectious status
what is standard precautions
gloves, gowns, goggles/face shield when working with body fluids, non-intact skin and mucous membranes
what do you do for contact precautions
- using gowns and gloves for all patient contact
- patient in a single room
which types of diseases would you do contact precautions
- diarrhoea
- excessive wound drainage
- multidrug resistant organisms
- respiratory viruses
what do you do for droplet precautions
- using surgical masks for all patient contact
- single room for patient
what do you do for airborne precuations
- negative pressure ventilation room
- N95 mask for all patient contact
what is the definition of sterilisation
the process of killing or removing all viable organisms, including viruses, bacteria, fungi and spores
what is the definition of disinfection
the process that eliminates many or all pathogen microorganisms on inanimate objects with the exception of bacterial spores
what is the definition of cleaning
the removal of visible soil from objects and surfaces
what is the spaulding classification
a classification of objects into critical, semicritical and noncritical disinfection depending on the objects use
which objects are “critical”
those that enter normally sterile tissue –> need to be sterile
which objects are semicritical
objects that touch mucous membranes or skin that is not intact –> need to be disinfected
which objects are noncritical
objects that touch only intact skin –> require low level disinfection only
what do you use to sterilise an object
- usually steam
- for heat sensitive objects - other ways (hydrogen peroxide etc)
what is asepsis
free from infection or infectious material
what is ANTT
a technique used to prevent contamination of equipment and skin breaches by microorganisms that could cause infection
what is in skin preps
combination of alcohol and chlorhexidine or alcohol and iodine
what is the difference in action between chlorhexidine and iodine
chlorhexidine is not inactivated in the presence of organic material, while iodine is
what is the most common source of nocosomial infection
patients own microbiota
what is sterility assurance
the probability that the instrument is sterile
What is the D value for a sterilisation procedure
the rate of kill - the time to reduce microbiota population 10 fold
what is the antibiotic that is used as a surrogate for methicillin for “methicillin resistance testing”
cefoxitin
what are the most common organisms causing endocarditis
staph aureus strep viridans enterococci strep pyogenes staph epididermis
which patients are the most susceptible to endocarditis
those with damaged valves
what four things do you need to know to design an appropriate sterilisation process for a particular instrument
- type and level of contamination
- rate of biocidal action of agent (D value)
- level of sterility assurance required
- will the item survive the process
why does a patient develop pseudomonas colitis
AB treatment –> kills rest of the microbiota in the gut –> then able to grow and produce toxins –> mucosal damage
which nosicomial organisms respond well to alcohol-based hand hygiene programs, and which do not
do = MRSA and gram-negative infections don't = C. difficile, pseudomonas
what is the thought around the source of VRE
- about half arise de novo by microbiota passing on Tn1540 (Resistance plasmid)
- direct patient contact
