Chapter 10 Disinfection
5 Factors that effect the effectiveness of disinfectants
1. Type and level of microorganisms 2. Direct contact with item 3. Temp of disinfection 4. Ph Levels 5, Material compatability
OPA soak time
12 minutes a t room temperature 68f 20c in a manual system or 5 minutes at 77f 25 c in an automatic endoscope reprocessor to destroy all pathogenic microorganisms.
Glutaraldahyde
A 2% alkaline solution with a pH of 7.5 -8.5 kills microorganisms by alkylation of protein
Disinfectant
A chemical which kills pathogenic organisms, but does not kill spores, and is not a sterilant. Used on inanimate objects . Can not make objects sterile.
Families chemicals
A group of chemicals that have similar characteristics
Sterilization
A process by which all forms of microbial life including bacteria, viruses, spores and fungi are completely destroyed.
Antiseptics
A solution which inhibits the growth of bacteria. Usually used topically and only used on animate objects. Slows the growth of microorganisms on living tissue
Nonlipid Virus
A virus which nucleic acid core is not surrounded by a lipidenvelope. These Viruses are generally more resistant to inactivation by disinfection.
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 disinfectanats, including low level disinfectants.
Quats
Are cationic surface active compounds also known as wetting agents. They lower surface tension of the solution and allows greater penetration of the disinfectant into the soil.
AER
Atuomatic endoscope reprocessor
Mycobacteria
Can be destructed by High Level disinfection
Prions
Can be destructed by extended sterilization times.
Fungi
Can be destructed by intermediate level disinfection
Non Lipid and small viruses ( poliovirus)
Can be destructed by intermediate level disinfection
Gram Positive and Negative Vegatative Bacteria
Can be destructed by low level disinfection
Bacterial Spores
Can be destructed by sterilization
Phenolic residues
Can cause skin irritation, and even skin depigmentation if exposed to phenolic residues left on instruments
Sterile
Completely devoid of all living microorganims.
Cationic
Compounds that contain a postivie electrical charge on the large organic hydrophobic molecule, cationic detergents exhibit germicidal properties.
Anionic
Compounds which have a negative electrial charge on the large organic portion of the molecule which is relavtively hydrophobic and lipophilic. These form the large group of synthetic detergents.
Classification of Patient Care Items
Critical items, semi-critical items and non-critical items
Alcohol
Denatures (changes the structure of) proteins. 70% isopropyl alcohol possessess the most effective disinfectant properties. 70 % gets into the cell wall
After OPA immersion
Devices should be thoroughly rinsed by completely immersing it in a large volume 2 gallons of water. Repeat this procedure twice with fresh water rinse.
Thermal Disinfection
Disinfection done by heat. Kills are organisms except spores.
Two agencies that regulate chemical germicides
EPA and FDA
Kills Microorganisms by aklylation of protein
Glutaraldahyde
Turns green when activated Has a sharp odor Ittitant to skin eyes and res. System Can cause occupation asthma
Glutaraldahyde
Levels of Formaldehyde
High Level 8 percent formalin plus 70 percent alcohol Intermediate Level 4 to 8 percent formalin in water Low level less than 4 percent limited activity against tb
Glutaraldehyde
High level disinfectant used for semi critical devices such as endoscopes, and ultrasonic probes used in radiology. Avtivation of the solution is usually accomplished by mixing the solutions with a pre-measured activator
Three levels of disinfectants
High-Level Intermediate Level and Low Level
Buffered iodine
Poisons cells of nucleic acids, quickly pentetrates the cell walls of microorganisms
High Level Disinfectants
Process that utilizes a sterilant for a shorter contact time than that used for steriliaztion. And that kills all microbial organisms but not necessarily large numbers of bacterial spores.
Low Level Disinfectants
Process that utilizes an agent that kills vegatative forms of bacteria, some fungi and lipid viruses.
intermediate Level Disinfectants
Process that utilizes an agent that kills viruses, mycobacteria, fungi, and vegatative bacteria, but not bacterial spores.
Quarternary Ammonium Compounds
QUATS, low level disinfectant. Benzalkonium choride and cetylpyridinium chloride are members of this family
The Joint Commision
Regulates mechanical washers and washer decontamination
Bacterial
Relating to the destruction of bacteria
Used to accomplish sterilization
Steam pressure autoclaving, dry heat and low temp. methods (ethylene oxide gas, hydrogen peroxide (gas plasma) ozone, and liquid parasitic acid
Risk levels are based on
The Spaulding Classification system adopted for use by the cdc
Disinfection
The destruction of nearly all pathogenic microorganisms on an inanimate objects.
Ceiling limit
The employees exposure to an air component which shall not be exceeded during any part of the work day. If instantaneous monitoring is not feasible then the ceiling shall be assessed as a 15 minute time weighted average exposure which shall not be exceeded at any time over a working day
Shelf Life (disinfectants)
The length of time a disinfectant can be properly stored after which it must be discarded
Use Life ( disinfectants)
The length of time or number of times used after which the efficiency of a disinfectant is disminished.
Mec Miminum effective concentration
The percentage concentration of the active ingredient in a disinfectant or chemical steriliant that IA the minimum concentration at which the chemical meets all its label claims for activity against specific microorganisms.
Mechanical Washers
Use high pressure, high temp water jets to disinfect
OPA solution test strips
Used to assure that the mec of 0.3 % is present. The OPA solution may be used and reused for up to 14 days and then discarded.
A longer contact time
When liquid chemicals are labeled as both a high level desinfectant in a sterilant what is the time difference
EPA and FDA
Which agencies regulate the chemicals germicides utilized in health care
Cholorine
inhibits some key enzymatic reactions within the cell denatures proteins, and inactivates nucleic acids.
Summary of QUATS
mode of action - inactivates energy producing enzymes and denatures essential cell protein and disrupts cell membranes
Ortho-Phthaladehyde OPA
most commonly used high level disinfectant that provides a fast and effective way to disinfect a wide range of instruments and endoscopes.
Commonly used disinfectants
quaternary ammonium compounds, phenolics, alcohol, halogens, glutaraldehyde, ortho-phtalaldehdye, formaldehyde
14 to 28 days
Most glutaraldehyde based instrument sterilants are labeled for reuse during this period,.
Formaldehyde
Inactivates microorganisms by alkylation.
Red bagged, regulated as medical waste
Infectious waste is caterogrized as
Critical Items
Instruments or objects indroduced directly into the blood stream or into other normally sterile areas of the body. Sterile Body Cavity requires sterilization
Halogens
Intermediate level disinfectant that have similar elements possessing some unique properties. This family is known for its reactivity and two memebrs (cholrine and iodophores) possess disinfecting and sterilizing properties.
Phenols
Intermediate to low level disinfectants containing phenol (carbolic acid)
Iodophors
Iodine. Reactive member of the halogen family.
Semi Critical Items
Items that come in contact with mucous membranes but do not ordinarily penetarte body surfaces. High Level Disinfection
Non Critical Items
Items that usually only come in contact with unbroken skin. low level disinfectant
High level disinfectant
Kills alkalation
Lipid or medium size virusus ( Herpes, Hantavirus)
Low Level Disinfection
MEC
Minimum effective concentration
High Level Disinifection
Minimum sterility recommended by the cdc
Summary oh Phenolics
Mode of action - penetrates cell wall and precipitates cell protein
