W2: MB- Disinfection & Sterilisation Flashcards
What can we do to reduce incidence of infectious disease
transmission?
direct contact= highest risk
Definition of antisepsis, sanitisation, disinfection, sterilisation,
biocidal, biostatic and what type of microbes are susceptible to
each stage.
- immunisation
- barrier- PPE
- Isolation
- Disinfection/ steri
Know the appropriate level of microbial reduction strategy
depending on the clinical use of the equipment.
- clean Vs dirty area
- hand washing
- consider ALL infectious so you practice all these strategies
Know the different types of sterilisation and disinfection
methods and how they kill micro-organisms
Know factors that will affect the efficacy of these methods.
Local study at Maq Uni. Swabbed ICU livo hospital. cleaned with conc chlorine beyond normally used, 3-4 times after then swabbed. Bacteria still present
e.g. vancomycin - last resistant AB bacteria we have.
link= another UK study
What is the length of time required for proper
hand washing?
1 min
5 moments of hand hygiene in dental + Oral
b4 pt
b4 tx
after tx
aft touch pt
after touch pt surroundings
Is HH practiced? Why must it be…
local study
done in bunch healthcare settings across aus
- scientist spoke to compliance officers
- what is recorded lvl of HH compliance? reports= blue
- actual: over 60% difference in report vs actual practice
Categories of IC
on yourself
not on yourself
Who is the father of Anti-sceptic surgery? What did he do?
says that MB cause disease.
soaked bandage carbolic acid- on fracture- no infection post 6 wks
What is classification of IC?
Why multiple cleans?
1st step clean= remove visual
last 2 steps= hard to get sf contaminated again
what to do when suspected spore contamination?
bacterial spores have really thick coating
automatic autoclave 121 degrees to kill spore
- staph is least resistant
How to check if steri has been successfully carried out?
What criteria is considered in IC
- E
- comp. some material can breakdown gloves, etc
3.
Ideal cleaning solution factors are:
Cell membrane disruption mainly caused by
soap break down, make pore in membrane of bacteria, stops membrane from healing and it breaks
How can DNA damage be done ?
- perm degrade
- oxidise backbone
- unstable molecule into DNA so it can’t replicate
- thymine dimer= when you expose DNA to UV, therer is higher chance of same base forming bnd with itself. makes DNA non sensical, bacteria DIES
- protein damage
Protein damage MOA
- 2 random proteins form together
- denaturation can be reversible overtime
Physical vs Chemical IC
- physical= dry heat
- wet= autoclave
- filtration/ radiation
NOTE: dry vs wet heat. timing shorter, temp shorter.
Adv vs disadv
- radiation= risk
- time
- carcinogenity of chemicals
- chem can degrade instruments
Why steam?
enhance penetration of heat we need it to.
How is steri monitered?
mechanical: when you pop something in AC or UV chamber, you. have meters measuring pressure leaks
- chemical: colour changes in indicators
- biological: more time, used to check for presence of spores bc some spores can survive rlly harsh conditions. swab, send for tests, get results.
Factors affecting IC efficacy?
- what sf contaminated with, ABR?
- infection doses, if 1 lil bacterial cell not really infection, but 1million same bacteria= likely infection = infectious dose
- organic matter, time of expsure of steri, time to clean
Disinfection mehtods:
list of chem disinfectants. Most use EOG in hospital. diff effectiveness. normally alcohol on pts safer.
top 3= tools/sfv vary, some need gas cylinder
levels of of cleaning product = considered carcinogenic
10-15-20%
Example of risk of IC method
all has active compound that react with protein. cause MB death= react w proteina nd promote cross linking.
