ANES 1502 - M13 PPT - Disinfection

Disinfection

ANES 1502Anesthesia Technology Fundamentals I

College of DuPage

Copyright IAHCSMM 2007

Objectives:As a result of successfully completing this chapter, readers will be able

to:

Define the term, “disinfection,” and explain how disinfection differs from sterilization.

Review factors that impact the effectiveness of a disinfectant.

Discuss the relationship between the risk level (intended use) of the device to be disinfected and the selection of a disinfectant.

Explain disinfectant activity levels as they relate to the resistance of microorganisms to germicidal agents:

high-level disinfection intermediate-level disinfection low-level disinfection


Objectives: Review factors which affect the chemical action of and other important

selection considerations for disinfections.

Provide basic information about the types of disinfectants commonly used in healthcare facilities: quaternary ammonium compounds, phenolics, alcohol, halogens, glutaraldehyde, ortho-phthalaldehyde, and formaldehyde.

Review safety requirements that should be followed when using chemical disinfectants.

Define the term, “thermal disinfection,” and note key points to ensure that it is occurring.


Terminology Disinfectant - A

chemical used on inanimate objects such as medical instruments to kill all microorganisms , except spores.

Antiseptic – A chemical used on living tissue such as skin, to slow the growth of microorganisms.


Terminology

Sterile – Free from all living organisms.


Terminology

Disinfection – The destruction of nearly all pathogenic microorganisms on an inanimate surface. Disinfection is accomplished using chemical or heat processes.



Chemical Disinfection

Reduces the number of microorganisms on an object.


Factors Impacting the Effectiveness of Disinfectants:

Excessive Moisture – Excessive moisture can cause disinfectant solutions to become diluted. Lowering the concentration of the chemical disinfectant can reduce its ability to kill microorganisms.

Dilution

Disinfectants are designed to be used at a specific strength.

Type and number of microorganisms present.



Direct Contact with the Item.

In order to be effective, disinfectants must make direct contact with all surfaces being disinfected.


Time

Disinfectants must be allowed time to work.

Check manufacturer’s instructions for the correct exposure time required to achieve the desired biocidal effect.


Other Factors Impacting the Effectiveness of Disinfectants:

Temperature of the Disinfectant

pH

Hardness of the Water

Material Compatibility

Positioning of the Device(s) being disinfected

Selecting a Disinfectant

Should be based on: The intended use of the

device The degree of disinfection

required for the device.

Risk levels are based on the Spaulding Classification System


Critical Items Items introduced

directly into the bloodstream or other normally sterile areas of the body.

Surgical Instruments, Implants, etc.


Semi-Critical Items Items which come in

contact with intact mucous membranes.

Fiberoptic Endoscopes, Cystoscopes, etc.


Non-Critical Items Come in direct contact

with the patient’s unbroken skin.

Crutches, Blood Pressure Cuffs, equipment, etc.

Copyright IAHCSMM 2007Table Modified from Favero and

Bond, 1991

Classification of Patient Care Items

CriticalSterilizationSterile body cavity

Semi-criticalHigh-levelMucous membranes

Non-criticalLow levelIntact skin

Item ClassDestruction Method

Body Contact


Disinfectant Activity Levels

High-level

Intermediate-level

Low-level


High-Level Disinfection

Process that uses a sterilant for a shorter contact time that needed for sterilization. High-level disinfection kills all microorganisms, except bacterial spores.


Intermediate-Level Disinfection

Process that utilizes a agent that kills viruses, mycobacteria, fungi, and vegetative bacteria, but not bacterial spores.


Low-Level Disinfection

Process that utilizes a agent that kills vegetative forms of bacteria some fungi and lipid viruses.


Terminology Lipid Virus – A virus whose core

is surrounded by a coat of lipoprotein. Viruses included in this structural category are generally easily inactivated by many types of disinfectants, including low-level disinfectants.

Nonlipid Virus – A virus whose core is not surrounded by a lipidenvelope. These viruses are generally more resistant to inactivation by disinfectants.

Copyright IAHCSMM 2007Table Modified from Favero and

Bond, 1991

Hierarchy of Disease Producing Agents

Low-Level DisinfectionLipid or medium sized viruses (Hantavirus, Herpes Simplex Virus)

Low-level DisinfectionGram Positive & Negative Vegetative Bacteria

Intermediate-level DisinfectionFungi

Intermediate-level DisinfectionNonlipid and small viruses (Poliovirus)

High Level DisinfectionMycobacteria

SterilizationBacterial spores

Extended Sterilization TimesPrions

Destruction MethodOrganism Producing Disease


Factors Influencing Disinfectant Effectiveness:

Types of devices being disinfected.

Whether items can be disassembled.

Manufacturer’s recommendations.

Positioning of the device.

Process Quality Assurance Tests.

Shelf Life and Use Life.

Preparation required (mixing, etc.)

Reuse factors.

Additional inspections required by the manufacturer.


Common Disinfectants


Common Disinfectant Characteristics

A detailed overview of common chemical disinfectant characteristics can be found on pages 161 – 169 in the text.


Quaternary Ammonium Compounds (QUATS)

Low-Level Disinfectant

Advantages: Bactericidal, fungicidal and virucidal against

lipophilic viruses Built-in Detergent Properties


Quats Disadvantages:

Not sporicidal Generally not tuberculocidal or virucidal against hydrophilic

viruses Not Compatible with Soap Absorbed or Neutralized by Cotton or Charcoal Not effective against some gram-negative organisms

commonly found in hospitals


Phenolics Intermediate to Low LevelAdvantages:

Broad Spectrum of use; bactericidal for gram-negative and gram-positive bacteria, fungi, and tuberculocidal against lipophilic viruses.

Residual Activity* (can also be a disadvantage)


PhenolicsDisadvantages:

Not sporicidal Inactivated by organic material Corrosive to Rubber and some Plastics


Alcohol Intermediate-LevelAdvantages:

Rapid bactericidal agent against vegetative microorganisms, tuberculocidal, fungicidal, and virucidal.

Fast-Acting Non-Staining Leaves No Residue


Alcohol Disadvantages:

Requires a minimum 5 minute wet contact. No residual activity Volatile, flammable Inactivated by Organic Soil. Can dissolve lens mountings on certain

optical instruments Tends to harden and swell plastic tubing Not sporicidal


Halogens Chlorine

Iodophors


Chlorine Intermediate-Level Advantages:

Effective against Gram-Positive and Gram-Negative Microorganisms, Tuberculocidal, Fungicidal, and Virucidal

Rapid-Acting


Chlorine Disadvantages:

Inactivated by Organic Matter Corrosive to Metals Not Sporicidal Stains fabrics, plastics and other synthetic materials Relatively Unstable


Iodophors(Buffered Iodine)

Intermediate-Level Advantages:

Bactericidal, Tuberculocidal, and Virucidal Rapid-Action against vegetative bacteria


Iodophors(Buffered Iodine)

Disadvantages: Corrosive to Metals Detrimental to Rubber and some Plastics May burn tissue Stains fabrics and other materials May require long contact time to kill some fungi


Glutaraldehyde High-Level Disinfectant/Sterilant

Advantages: Kills vegetative bacteria (within 2 minutes)

Bactericidal (gram-positive and gram-negative), tuberculocidal, fungicidal, virucidal, sporicidal (For sterilization (killing spores) the soak time ranges 6-10 hours).


Glutaraldehyde Disadvantages:

Noxious odors, good ventilation required Unstable (14-28 product life) Dilution of product reduces activity Vaporizes No cleaning ability Rinsing Required Employee Health Concerns


Ortho-Phthaldaldehyde(OPA)

High-Level Disinfectant

Advantages: Fast-acting User-friendly Compatible with a wide range of endoscopes and medical

devices Requires no activation or mixing


OPA Disadvantages:

Does not have sterilant label claim Improper rinsing can cause staining of patient

tissues Patient with a history of bladder cancer should not

be exposed to items processed by OPA


Formaldehyde Available in different concentrations as a Low,

Intermediate, and High-Level Disinfectant

Advantages: Bactericidal, tuberculocidal, fungicidal, and virucidal

Sporicidal (as 8% Formaldehyde/70% alcohol)


Formaldehyde Disadvantages:

Inactivated by organic material May stain fabrics, plastics, and other synthetic

materials Not sporicidal Carcinogen (1PPM, 8 hour TWA) Irritating fumes Corrosive


Using High-Level Disinfectants

Follow manufacturers’ instructions Use appropriate containers Cover the containers Wear gloves Reuse only those products labeled for reuse Watch expiration dates Test as necessary Rinse thoroughly Dispose of according to established guidelines


Documentation A Log Book should be

maintained for high-level disinfectants.

(See page 171 of the text for a sample log book page.)


Chemical Disinfectant Safety

Wear PPE Use an exhaust hood when necessary Develop a spill plan Provide an eyewash/shower and other first aid

supplies Provide easy access to a phone and phone

numbers for emergencies


Chemical Disinfectant Safety

Provide yearly staff training

Monitor disinfectants (including air quality)


Thermal Disinfection

Thermal Disinfection – Disinfection accomplished by heat.


Thermal Disinfection

Check spray arms and nozzles of mechanical washer/disinfectors daily to insure they are working correctly.

Medical washers and washer/disinfectors are regulated by the FDA.


Questions?

Education

ANES 1502 - M13 PPT - Disinfection