10. Sterilisation And Disinfection Flashcards
LOs
Disinfection definition
“The destruction or removal of all or nearly all pathogens, but not all microorganisms”
This process may not be absolute and may result in only a reduction in the number of potentially harmful microorganisms. E.g. spores
Disinfection invariably relates to the killing or removal of virulent microorganisms; but not always their total elimination
Sterilisation definition
“The destruction or removal of all microorganisms”
•Bacteria, viruses, fungi, algae, protozoa and their spores
This is an ‘absolute’ and at the end of a sterilization process, no viable microorganisms are present
Decontamination definition
“Decontamination is a combination of processes carried out to render a contaminated reusable medical device safe to use again”
•Not a sterility absolute; it depends upon the nature of the equipment and the use characteristics for the types of procedure for which they are required.
Classification of Procedural Risk Related to Decontamination Requirements
- Category of IC risk
- Procedure type (use characteristics)
- Level of decontamination required
- each instrument that you use can be given a risk category
why do dental instrument and equipment need to be decontaminated
- basic principle is that if something can be sterilised, it will be
- a lot of instruments used cannot be single use and cannot be sterilised easily EG a lite cure unit
what is the single-use symbol
Cross-Contamination and/or Cross-Infection definition?
- cross- contamination = spreading microorganisms from one place to another
- cross infection = giving someone an infection because we’ve cross contaminated them
“The transmission of a microorganism (infection) from one place/person to another in the same healthcare environment ” = a big issue for dentists
…To occur it requires a number of factors (6) to be in place
are the terms cross infection and cross contamination still used?
- the term infection control is used more now currently as we are trying to stop infection and control the contamination that causes it
why is infection control important to us as dentist?
- what we do in our environment makes us legally liable
- as soon as patient walks into surgery, the dentists have a duty of care to prevent them from coming into contact with potentially infective microorganisms
What needs to occur for cross infection to occurs
- requires a number of factors (6) to be in place for it to occur
- if all 6 are in place you can get transmission and an infection caused by cross contamination
- if you break the chain you can prevent this happening
Types of infection agents transmissible during healthcare procedures
What are reservoirs? Where are they?
- commonly in complex instruments (if not sterilised correctly will harbour bacteria)
- water supplies if not regularly checked (can grow significant levels of microorganisms as working in environment which are already highly bacteria colonated areas anyway - EG plaque amount = 10^11 cfu/ml)
CFU meaning?
Colony forming unit
instruments we use can be split into 2 different categories
How do they exit from equipment use into patient?
-Hands
↳ most common area of cross contamination
↳ clean hands do not transmit but if not cleaned properly then bad
- introduced through contaminated solid instrument
- can spray into patients mouth through aerosols via drills
How is it transmitted?
(Mechanisms of cross contamination)
- Direct contact: infectious agent transmission from the same or different person
- Indirect contact: via instruments and equipment
- Inhaled/airborne: DUWL’s, sneezing, coughing etc
- Ingested: food and water hygiene
- Vector: clothing, towels, insects, animal contact etc
portal of entry of infection?
once it’s in, it can get in through:
- gingival margin
- cavity that the patient might have (such as surgical wound)
- area of infection patient is exhibiting
- area of unintact mucosa or skin
- area of non-healing bone
- several ways if we’re not directly injecting it that the patient is still susceptible to infection
- patient needs to be susceptible to it
- many patients have conditions that put them at higher risk of getting an infection
- have a weakened immune system
- health care associated (acquired) infections in diagram
How are medical devices decontaminated?
Decontamination cycle stages
Can instruments be packaged if they’re going to be put through a non vacuum autoclave during the decontamination cycle? why?
- no
- packaging would only be used if the instruments are going to go through a vacuum autoclave
- cannot package if putting in a non-vacuum autoclave
BECAUSE - the non-vacuum wouldn’t penetrate the package that you put the instrument into
- special packaging allows steam to penetrate through the package
- hence only put instruments in packaging before sterilisation if they’re going to be sterilised in a vacuum autoclave
Decontamination cycle stages equipment?
TRANSPORT
- trolleys on clincis where you can put used instruments that have been bagged up into non-sterile bags so they can be taken into central sterilising department (CSD)
CLEANING
- may need to be manually cleaned or automatically cleaned
DISINFECTION
- ultrasonic disinfectant (has chemicals in it that will denature proteinaceous material - EG bacteria, viruses, etc)
- or could just be cleaner, EG handpiece oiler and cleaner
- automated washer disinfector
INSPECTION
- labs use magnification
PACKAGING
- allows steam to penetrate but water cannot come back in once dried
STERILIZATION
- 3 types of autoclave (non-vacuum (N type), vacuum (B type), specialised (S type))
TRANSPORTED AND STORED
-back to suitable storage areas
Modifying factors for effective disinfection and sterilisation
Some pieces or equipment cannot be sterilised so we run the risk of transmitting potentially infecting organisms to the next patient
Hence we:
↳ barrier cover them (reduced bioload to equipment)
↳manually disinfect chemically in between patients
Disinfection types
Automated water disinfectors stages
Sterilisation types
Autoclave sterilisation parameters
Autoclave steriliser types
Autoclave sterilisation cycles
In summary know
