infection prevention and control Flashcards
what is the prevalence and problem with HCAI?
costs the NHS round £900 million per annum
relative risk of death is 7.12
around £3000 extra per HCAI
estimated 5000 deaths per year from HCAI
what is the chain of infection?
a pathogenic organism with sufficient virulence and numbers to cause illness, goes into a reservoir or source that allows it to survive and multiply. There is a mode of exit from the source and then transmission into the host. There must be a portal for entry into the host and then infects the susceptible, non immunised host
what is infection prevention and control?
activities undertaken with the aim of breaking the chain of infection
what are the steps in infection prevention and control?
eliminate the pathogenic organism, remove source or reservoir, minimise transmission, eliminate entry and exit and reduce susceptibility to infection
how can we eliminate pathogenic organisms?
environmental cleaning and decontamination through H2O2 room decontamination, spillage management and laundry, equipment decontamination through disinfection and sterilisation, antisepsis and antibiotic prophylaxis
what are two cases when antibiotic prophylaxis may be given?
post exposure and peri-operative
what are two examples of antisepsis?
MRSA decolonisation and surgical skin prep
how can the source or reservoir be removed?
through hand hygiene and environmental cleaning and decontamination
how can transmission be minimised?
hand hygiene, PPE, equipment decontamination, single use disposable equipment, source and protective isolation, semmelweis
what is included in PPE?
personal protective equipment:
aprons
gloves
masks
what equipment should always be decontaminated?
surgical instruments, stethoscopes, blood pressure monitors, USS probes
what is an example of single use disposable equiopment?
needles and syringes
what is semmelweis?
using the antiseptic procedure
when are the five times you wash hands?
before patient contact, before aseptic task, after bodily fluid exposure risk, after patient contact and after exposure and contact to patient surroundings
what is the issue with hand hygiene?
they contain resistant bacteria that are deep seated and difficult to remove
what is hand hygiene particularly useful against?
transient bacteria
what are transient bacteria?
they are bacteria (also found on hands) that are easily picked up and transferred and easily removed. They are a major cause of HCAI due to this.
what is the role of resident bacteria and when are they moved?
to protect us from colonisation of harmful bacteria - removed in aseptic procedures
why are aseptic procedures performed?
to reduce the risk of contamination when inserting invasive devices or performing surgery
when is soap and water used to clean hands?
when the hands are visibly soiled, for certain infections and contact with such as gastroenteritis and C difficile, and on entry and exit from any ward
when is alcohol gel used?
when hands are not visibly dirty or when doing a non direct contact activity
what is decontamination?
it is a combination of processes that removes or destroys contamination so that infectious agents or other contaminants cannot reach a susceptible sits in sufficient quantities to initiate infection or other harmful response
how many decontamination methods are there?
there a many - which one to use depends on the individual situation
what is sterilisation?
it is the complete killing or removal of all types of microorganisms
when is sterilisation used?
on single use disposable equipment
what methods are there for heat sterilisation?
moist, dry, autoclave, oven, specific pressure and temperature cycles (160 degrees for 2 hours and 170 for 1), delivery of steam under high pressure
what other ways of sterilisation are there?
chemical, gas, moist, dry, liquid, filtration, ionising radiation
what is disinfection?
it is the removal or destruction of sufficient numbers of potentially harmful microorganisms to make an item safe to use
what is antisepsis?
it is disinfection of damaged skin or living tissue - requires a disinfectant with minimal toxicity
what is almost always used in disinfection?
chemical products
what properties of disinfectants are considered and why?
the effect on the microorganism (antimicrobial spectrum and sporicidality), chemical properties (shelf use, in use concentration, compatibility with other chemicals), physical properties such as corrosiveness and harmful effects - irritant potential and toxicity
heat is the preferred option for sterilisation and for disinfection, when is chemical disinfection used?
in environmental decontamination, antisepsis and heat sensitive methods
how is risk of infection classified?
high intermediate or low
when do you a) sterilise, b) disinfect and c) clean?
a) items or devices that enter sterile body areas or break the skin and all reusable surgical instruments
b) items or devices that contact mucous membranes or are contaminated with bodily fluids
c) items or devices that only contact intact skin
what must occur before sterilisation and disinfection?
thorough cleaning
what is cleaning?
it is the removal of dirt, dust or any organic matter using water and detergent - it will remove around 80% of organisms if dried afterwards.
what is cleaning suitable for?
any item that comes into contact with intact skin and prior to disinfection and sterilisation
what is surgical instrument reprocessing?
it is the decontamination method for surgical equipment
what comprises surgical instrument reprocessing?
the high risk of infection, the metal construction and paper cloth packaging for physical properties, resulting in a decontamination level of sterilisation and method of using moist heat
how would a flexible endoscope be decontaminated?
the risk of infection is high, but it has metal and plastic construction, is not in contact with sterile area, and has fragile sensitive parts. Therefore the decontamination method is high level disinfection with chemicals or other alternative agents that are delivered via washer disinfector
how is a syringe needle decontaminated?
it has a high risk of infection with plastic or metal construction and paper packaging. It is single use so sterilisation is used using y-irradiation pre use and disposal after use
how would you decontaminate a central venous catheter insertion site?
it is living tissue and therefore you use disinfection - antisepsis. It is done chemically with 2% chlorhexidine and 70% isopropyl alcohol
how would a surgeon decontaminate?
it is living tissue that is decontaminated with washing using surgical scrub
