Cleaning, Disinfection, and Sterilization Flashcards
what does the Spaulding classification system do?
Divides medical equipment into 3 categories based on risk?
environmental decontamination plays a role in decreasing
bioburden
what is considered an environmental surface?
non critical items in the SCS and high touch surfaces
what is the level of microbial inactivation for sterilization?
detroys all microrganisms including bacterial spores
what is the level of microbial inactivation for high level disinfection (HLD)?
destroys all microorganisms except high number of bacterial spores
what is the level of microbial inactivation for itnermediate level disinfection?
destroys vegetative bacteria, mycobacteria, most viruses, most fungi but not bacterial spores
what is the level of microbial inactivation for low level disinfection?
destroys vegetative bacteria, some fungi and viruses but not mycobacteria or bacterial spores
what are 3 methods of sterilization?
- high temperature
- low temperature
- liquid immersion
what are 2 methods of HLD?
- heat automated
- liquid immersion
____ _____ is the method of intermediate level and low level disinfection
liquid contact
low level disinfection would be used for what?
cleaning non critical patient care items with no blood
intermediate level disinfection would be used for what?
cleaning non critical patient care items with visible blood
an example of heat automated HLD is
pasteurization (for respirator equipment)
an example of equipmentthat uses liquid immersion HLD is
heat sensitive semicritical items (endoscopes, bronchoscpoes, endocavitary probes)
high temp sterilization would be used for what
heat tolerant critical and semi critical items (surgical tools)
low temp sterilization would be used for what?
heat sensitive critical and semi critical items
liquid immersion sterilization would be used for what?
heat sensitive critical and semi critical items that can be immersed
what are examples of low temp sterilization?
-ethylene oxide gas
-hydrogen peroxide gas plasma
-ozone
-hydrogen peroxide vapor
cleaning instruments after use reduces
spillage and aerosolizing of contaminants
Instruments should be kept ____ after the removal of contamination and before transport
moist
how can instruments be kept moist before transport?
-special containers
-pre treatment product
-towels moistened with water
instruments used in the ER that undergo sterile processing should be immediately sprayed with what?
an enzymatic cleaner
True or false. ER tools should not be cleaned throughout the procedure.
False. Clean them so bioburden doesn’t adhere
what is the most important step in the reusable medical equipment process?
cleaning and rinsing
contaminated items should be transported in what
-closable, puncture resistant, leak proof container marked biohazardous. Adhere to standard precautions.
what are 2 components to manual instrument cleaning?
friction and fluidics
fluidics is used for
removing soil and debris from inner channels after brushing and when the design does not allow for the passage of a brush through a channel
why does fluidics happen under what?
to prevent aerosolization
Mechanical units for instrument cleaning include
ultrasonic cleaners or washer disinfectors
how does ultrasonic cleaning remove soil?
by cavitation and implosion where waves of acoustic energy are propagated in acqueous solutions to disrupt the bonds that hold particulate matter to surfaces
with what cleaning unit can the cleaning fluid result in endotoxin contamination of surgical instruments that could cause severe inflammatory reactions?
ultrasonic cleaners
where are ultrasonic cleaners used?
-dentist office
-hospitals
-ambulatory care
describe washer decontaminators/disinfectors?
they act like a dish washer that uses water circulation and detergents to remove soil. . Sometimes subject instruments to heat (93C for 10 mins)
describe washer sterilizers
modified steam sterilizers that clean by filling the chamber with water and detergent through which steam is passed for agitation. Instruments are then rinsed and subjected to a short steam sterilization cycle.
Which cleaning unit is used for respiratory therapy equipment?
washer pasteurizers
items must be sterile when they enter what body areas
-stertile tissue
-bone
-the vascular system
True or false. Sterile items do not need to be purhcased as sterile p
False
critical instruments include
-surgical instruments
-urinary and cardiac catheters
-implants
-ultrasound probes that enter sterile body cavities
what is the preferred method of sterilization?
steam sterilization
what is a limitation of chemical sterilants?
Can’t be wrapped during processing which creates a challenge for maintaining sterility after processing and during storage
Do devices requrie rinsing after chemical sterilants?
yes with either sterile or filterered water
When should chemical sterilants be used?
for devices that are heat sensitive and incompatible with other sterilization methods.
what are examples of semicritical itesm
GI endoscopes, bronchoscopes, laryngoscopes, esophageal manometry probes, infrared coagulation devices, diaphragm fitting rings
true or false. Intact mucous membranes (those of the lungs and GI tract) are generally resistant to infection by common bacterial spores.
True
semi critical items minimally require what?
HLD with chemical disinfectants
What are some examples of high level disinfectants?
-Glutareldahyde
-hydrogen peroxide
-ortho-phthaladehyde
-improved hydrogen peroxide
-peracetic acid with hydrogen peroxide
-chlorine based products
How often should areas that do reprocessing be audited?
at least annually
non critical items can be divided into which 2 categories?
- non critical patient care equipment
- noncritical environmental surfaces
what are some advantages of local reprocessing?
-faster turnaround
-less instrument loss
-lower instrument inventory
what are biofilms?
microbial massess attached to surfaces immersed in liquids
What mechanisms do biofilms use to become resistant?
-high resistance of older biofilms
-genotypic variation of the bacteria
-microbial production of neutralizing enzymes
-physiologic gradients within the biofilm (i.e., pH)
biofilms are how many times more resistant than the same bacteria in suspension?
1000x
where have biofilms been found?
-whirpools
-dental unit waterlines
-pacemakers
-contact lenses
-urinary catheters
what causes TASS?
substances that enter the eye during surgery and breaches in disinfection and sterilization
-detergent residues, salt solutions, antiseptic agents, talc from gloves, impurities of autoclave steam, heat stable endotoxin
70% of cervical cancers are attributed to what HPV strans?
16 and 18
when is special prion reprocessing required?
when crticical and semi critical devices are contaminated wth high risk tissue (brain, spinal cord, eye) from a patient known or suspected with CJD
why do you want to maintain a moist environment with CJD at the point of use?
so the protein and prion amyloid can’t attach to the stainless steel surface
Define sterile or sterility
state of being free from all microorganisms. Usually a probability function.
Define sterility assurance level (SAL)
The probability of a single viable micoorganism occuring on a product after sterilization. It is an estimate of lethality of the entire sterilization process.
What process is defined as the process of preventing contact with microbes?
Asepsis
What is aseptic technique?
The process of carrying out activities that will maintain objects are areas free of microbes to the greatest extent possible.
Who developed the first presure steam sterilizer (autoclave)?
Charles Chamberland in 1876
Why is dry heat sterilization rarely used?
because of lengthly exposure times
True or false. Steam leaves behind chemical residues and byproducts
False
Subjecting items to the thermal energy from moist heat (steam) can be defined as
high temperature sterilization
What is the most important step in sterilization?
cleanining
What is the basic principle of steam sterilization?
expose each item to the steam contact at the required temperature and pressure for the specified time/
What are the 4 parameters of steam sterilization?
- Steam (moisture)
- Time
- Temperature
- Pressure
What are the 2 main types of steam sterilizers?
- dynamic air removal sterilizer
- gravity displacement sterilizer
most hospitals use what type of steam sterilizers?
jacketed
describe the anatomy of steam sterilizers
steam is applied through a main steam line, these units themselves do not generate steam. chamber walls will be heated by the steam in the jacket.
What are some components of a steam sterilizer?
-door
-gasket
-chamber drain
-thermostatic trap
What is the weakest part of a steam sterilizer?
the door
What is the role of a gasket in a steam sterilizer?
creates a tight seal so steam cannot escape
where is the chamber drain located in a steam sterilizer?
the front or center of the floor
what is the function of a thermostatic trap in a steam sterilizer?
allow air and water (condensate) to escape from the chamber. remove the condensate while preventing the passage of dry steam. they are usually temperature sensitive valves that close when heated past a certain set point.
what is the temperature of a gravity displacement steam sterilizer?
250F
which requires a lower temp gravity displacement or dynamic air removal?
gravity displacement
describe how a gravity displacement steam sterilizer works
steam is admitted at the top or sides of the sterilizing chamber and (because steam is lighter than air) forces air out the bottom of the chamber through the drain vent. Require more exposure time because air removal is more passive in nature.
What is the temperature of dynamic air removal sterilizers?
270-275F
What is an advantage of dynamic air removal sterilizers?
uses a vacuum pump so there is nearly instantaneous steam penetration even into porous loads
Describe the process of dynamic air removal sterilizers
aHigh-speed pre vacuum sterilizer. vacuum pump (or ejector) ensures air removal from the sterilizing chamber and load before the steam is admitted.
How do steam flush pressure pule sterilizers work?
removes air rapidly by repeatedly alternating steam flush and a pressure pulse above atmospheric pressure. Air is rapidly removed from the load as with the prevacuum sterilizer, but air leaks do not affect this process because the steam in the sterilizer is always above atmospheric pressure.
Which time of sterilization use to be referred to as flash?
immediate use
when would IUSS be used?
in an emergent situation like during a surgery and it has to be cleaned. A one of a kind instrument with no other way to clean it
the time required for flash sterilization depends on what?
the type of sterilizer and type of item (i.e., pourous or non-pourous)
Where would flash sterilizaton occur?
in a gravity displacement sterilizer
why is flash sterilization not recommended as a routine sterilization method?
-lack of biological indicators
-absence of protective packaging following sterilization
-possibility of contamination during transport
-sterilization cycle parameters are minimal