Cleaning, Disinfection, Sterilization, Asepsis (18 exam questions) Flashcards
Process for transporting surgical instruments to decontamination
- Clean off gross debris (bio burden) ASAP by wiping or irrigation (per IFU) with water with detergent or enzymatic. Keep moist
- Pre-soaking, transported in leakproof, puncture-proof container with biohazard label. (or case cart for surgical instruments)
- Manually or mechanical clean. Manually: use friction and neutral detergent under pressure (fluidics). Mechanical clean uses alkaline detergent
Non-critical (Spaulding classification)
contact with intact skin, not mucus membrane. Requires intermediate and low level disinfection (ex: stethoscope)
Semicritical (Spaulding classification)
Will contact mucous membranes or nonintact skin (Ex: RT or anesthesia equipment and some endoscopes)
* Should be free of all vegetative microorganism, but small number of spores may be present
* items require HLD with chemical disinfectant
*
critical (Spaulding classification)
involve high risk for infection if contaminated with microorganisms - enter sterile tissue, bone or vascular system
Sterilization
destroys all microorganisms, INCLUDING spores
* High- steam
* low- ethylene oxide
*Liquid immersion- chemical sterilant
High level disinfection
destroys all microorganism, EXCEPT high number of spores
* heat- automated- pasteurization
* liquid immersion- chemical sterilant
Intermediate level disinfection
destroys vegetative bacteria, mycobacteria, most viruses, most fungi, NOT spores
* Liquid contact- EPA registered disinfectant WITH tuberculocidal claim
Low level disinfection
destroys most vegetative bacteria, some fungi and viruses, NO mycobacteria or spores
* Liquid contact- EPA registered disinfectant WITHOUT tuberculocidal claim
Temp of steam sterilization
250°F (121°C) and 272°F (133°C)
For steam sterilization, you have to consider pressure, temperature, time, and moisture, The temperature must reach ____ to ensure the microorganisms are killed
Ethylene oxide (ETO)
exposure concern, long cycle (3-6 hours)
Glutaraldehyde
HLD
inexpensive, excellent material compatibility, 5-45 min cycle
Ortho-phthalaldehyde (OPA)
HLD that does not have a significant odor and generally does not cause respiratory irritation.
Drawbacks of OPA are that it can cause staining if it come in contact with skin, clothes, or surfaces and it is relatively expensive.
Vaporized hydrogen peroxide
safe for environment and HCW, no toxic residue, fast cycle (55 min)
Sterilization mechanical indicator
recording charts for time and temp, pressure gauges
Sterilization chemical indicator
chemically impregnated paper or strips, pellet in glass tube
*Bowie Dick test: used to check removal of air from sterilizer and efficacy of vacuum pump
Sterilization Biological indicator
spore strips Bacillus stearothermophilus or Bacillus subtilis
A biological indicator is the only method of assuring that a steam
sterilizer has reached the correct conditions to ensure sterility of products.
To determine whether the items being autoclaved are properly
sterilized, which is indicated by a negative BI result
Rationale: A biological indicator is a standardized, contained population
of microbes that is included in a sterilization cycle to indicate whether the
cycle was successful. The BI may contain spore-forming bacteria or other
highly resistant microbes, and sterilization should render these microbes
inactive. After sterilization, a BI is incubated at the optimum temperature
and time for growth of the microbe. A positive result occurs from microbial
growth, which indicates that the sterilization cycle was not optimal for
inactivation of all microbes.
*AAMI recommends biological indicator used in 1st load of each day (preferred) but at least once per week
* Causes of false-positive: accidental contamination of sterilized test strip in lab, defective biological indicator, contamination of growth medium with bacillus spp.
Steps for disinfection or sterilization (chemical sterilant or HLD)
- Clean: mechanically clean and flush all channels with water and enzymatic cleaner.
- Disinfect: immerse in HLD or chemical sterilant for time recommended on IFU
- Rinse: with sterile water, filtered water or tap water
- Dry : rinse channels with alcohol and dry with forced air
- Store: in a way to prevent recontamination and promote drying (hung vertically)
Tonometer (semi critical item) disinfection
- wipe clean and disinfect for 5-10 min with 5000 ppm chlorine or 70% ethyl alcohol
- thoroughly rinse in tap water and air dry before use
Diaphragm fitting rings (semi critical item) disinfection
- Clean with soap and water
- 15 min immersion in 70% alcohol
- should be adequate to inactivate HIV, HBV, HSV even though alcohols are not classified as HLD
probes (endocavity, US) (semi critical) disinfection
- use a probe cover
- HLD via liquid sterilant or sterilized between patients
*cryosurgical probes are not fully immersible
Which of the following is the best method for removal of all microbes from an instrument that is heat stable and water resistant
Steam Sterilization.
Steam sterilization involves the use of moist heat under pressure to raise the temperature in a sterilizer quickly to a critical temperature that will destroy all microbes, including spore formers. The process is relatively fast and is automated so it’s generally reliable. Instruments that can withstand exposure to high heat and moisture should be steam sterilized.
Reference: Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 Rutala WA, Weber DJ, Healthcare Infection Control Practices Advisory Committee
Decontamination is the process by which an item is
Rendered safe for handling without protective attire.
Decontamination according to OSHA, is defined as “the use of physical or chemical means to remove, inactivate, or destroy bloodborne pathogens on a surface or item to the point where they are no longer capable of transmitting infectious particles and the surface or item is rendered safe for handling, use, or disposal” [29 CFR 1910.1030]. In health-care facilities, the term generally refers to all pathogenic organisms.
If your only consideration in choosing a chemical disinfectant was to select one that does not irritate the respiratory system, which of the following would you choose
Ortho-phthalaldehyde (OPA).
Ortho-phthalaldehyde (OPA) is a high-level disinfectant that does not have a significant odor and generally does not cause respiratory irritation. Drawbacks of OPA are that it can cause staining if it come in contact with skin, clothes, or surfaces and it is relatively expensive.
leared by the U.S. Food and Drug Administration (FDA) and are dependable high-level disinfectants provided the correct parameters for time and temperatures are me
Glutaraldehyde, hydrogen peroxide, ortho-phthalaldehyde, improved hydrogen peroxide, peracetic acid with hydrogen peroxide, and chlorine-based products
The Association for the Advancement of Medical Instrumentation (AAMI) has proposed the use of ________ the benchmark for residual protein on medical and surgical instruments following cleaning of an instrument prior to sterilization.
< 6.4 µg/cm2as
Inadequate sterilization of surgical instruments and tubing
may result in which of the following adverse events after
cataract surgery?
Toxic Anterior Segment Syndrome
Rationale: Toxic Anterior Segment Syndrome (TASS) is an acute inflammation
of the eye that can occur following cataract surgery. A variety of substances
have been implicated as causes of TASS and include impurities of autoclave
steam, heat stable endotoxin, and irritants on the surfaces of intraocular
surgical instruments. General principles of cleaning and sterilizing intraocular
surgical instruments have been published and should be followed.
disadvantage of liquid sterilization
Items cannot be wrapped during the sterilization process
so sterility cannot be maintained during storage
Rationale: Liquid sterilization uses glutaraldehyde, hydrogen peroxide, or
peracetic acid to sterilize items that are critical and are heat-sensitive. This
is a liquid immersion process so items cannot be wrapped during the
sterilization process. In addition, items may need to be rinsed after the
process so sterility is not maintained in the rinsing, drying, and storage
phases. Therefore, this method of sterilization is used only when an item
cannot be sterilized in any other manner.
Cleaning process
Clean from least soiled (outside pt zone) to most soiled (pt zone) and then from high to low.
Clean to dirty, high to low
Types of tissue consider at high risk for CJD include
Tissues known to be highly infectious include brain, dura matter,
pituitary tissue spinal cord and eye;
tissues with LOW infectivity include lung,
liver, kidney, spleen, lymph and CSF
correct storage to maintain sterility of reprocessed items
*Items should be stored at least 18 inches below the ceiling and 8-10 inches above the floor. Storage should be at least
two inches from the wall and if a rack is used then it should have a solid
bottom to avoid contamination of items from dust on the floor
*The room must be positive pressure with a temperature of approximately 75°F, with a relative humidity not to exceed 70 percent
Ultrasonic cleaners are used for:
Fine cleaning of instruments
Rationale: Ultrasonic cleaners use sound waves to create bubbles that
disrupt small particles that may exist in hard-to-clean places on instruments.
Ultrasonic cleaners may be used after initial cleaning that removes all
visible and accessible soiling is carried out and before final disinfection or
sterilization, following manufacturer’s recommendations
CDC recommends that endoscopy-associated infections be
reported
to the person responsible for infection prevention at the facility; the
physician responsible for the care of the patient; the appropriate public health
agency (which is the FDA or CDC); and the manufacturer(s) of the endoscope,
disinfectant/sterilant, and automated endoscope washer-disinfector (if used).
Types of sterilitzation
- various types of steam sterilizers
*gas sterilizers including those that use ethylene oxide gas, ozone, and hydrogen peroxide gas or vapor
*liquid immersion in chemical sterilants.
Sterilization of instruments results in the instruments being free of
all microbes, including spores.
type of indicators is most accurate for assessing whether surgical instruments have been processed correctly in a
steam sterilization cycle
Biological indicator
Rationale: A biological indicator is the only method of assuring that a steam
sterilizer has reached the correct conditions to ensure sterility of products. Use
of a biological indicator provides reliable, qualitative evidence that all sporeforming
organisms have been inactivated during the sterilization cycle.
