Post on 19-Jan-2023
Endoscopes:
A flexible device used to visualize the interior of a hollow organ such as the GI tract, respiratory tract, urinary tract etc.
Flexible endoscopes are considered semi-critical devices because they come into contact with mucus membranes but do not ordinarily enter sterile tissue or the vascular system. At a minimum, endoscopes are to be cleaned, decontaminated and high level disinfected prior to re-use.
High Level Disinfection
An EPA registered chemical agent with a label claim as a high level disinfectant/sterilant is used per the manufacturer’s instructions for appropriate concentration, submersion and contact time to kill all microorganisms except high numbers of bacterial spores or prions that cause CJD.
Glut History
Tanning agent for leather Tissue fixative Preservative in cosmetics Therapeutic agent for warts & other infections X-ray processing solution & film emulsion
Uses of CIDEX A disinfectant A tanning agent in leather To sterilize endoscopic instruments,
thermometers, rubber or plastic equipment which cannot be heat sterilized
Glutaraldehyde Disinfection
•Broad spectrum antimicrobial “cold” disinfectant
•Glut action – bonds protein
•Device preparation – thorough cleaning and rinsing
•Efficacy monitoring
•Soak time controversy
Chemical Description Synonyms-- glutaric dialdehyde chemical
formula – C5H8O2
Poisonous, colorless liquid or powder salt Pungent odor Stable Non-flammable when in solution with water Turns green when activated
Glut Advantages
Effective for HLD Highly compatible Sterilization with long soak times Low cost, convenient
Glut Limitations Unstable - Effective life 2-4 weeks Thorough rinsing - mandatory Skin, respiratory hazards Glut bonds proteins
Options for alternatives: Other soaking solutions (Cidex OPA) or sterilization methods
Glut Hazards Skin & mucous membrane hazards Ingestion hazards Respiratory hazards Chronic exposure hazards
AAMI Document
“Safe use and handling of glutaraldehyde-based products in health care facilities”
AAMI: Association for the Advancement of Medical Instrumentation
New methods in disinfection and sterilization
Regulatory agency actionAgentProcess
FDA cleared, October 1999Ortho-phthalaldehyde (Cidex OPA)
Disinfection
Not FDA/EPA clearedAntimicrobial coating (Surfacine)
Not FDA/EPA clearedSuperoxidized water (Sterilox)
Not FDA clearedLiquid sterilization process (Endoclens)
Sterilization
Not FDA clearedRapid readout ethylene oxide biological indicator (Attest)
FDA cleared, January 1999New plasma sterilizer (Sterrad 50)
Ortho-Phthal-aldehyde (OPA)
Chemical Sterilizaer Advantages:
not eye and nasal passages irritant has excellent stability over a wide range of pH (3 to 9) has a barely perceptible odor Like glutaric aldehyde, it has excellent material compatibility
Disadvantage: It stains proteins gray (including unprotected skin)
OPA vs. Glutaric Aldehyde
Activity of glutaraldehyde and ortho-phthalaldehyde against Mycobacterium bovis
Time for 6-log10 reductionaDisinfectant 28-36 minutes1.5% glutaraldehyde14-18 minutes2.5% glutaraldehyde4.8-6.3 minutes0.21% ortho-phthalaldehyde
aRange of values from two different laboratories .
High Level Disinfection of “Semicritical Objects”
Exposure Time > 12 m-30m, 20oCGermicide Concentration_____Glutaraldehyde > 2.0%Ortho-phthalaldehyde (12 m) 0.55%Hydrogen peroxide* 7.5%Hydrogen peroxide and peracetic acid* 1.0%/0.08%Hydrogen peroxide and peracetic acid* 7.5%/0.23%Hypochlorite (free chlorine)* 650-675 ppmGlut and phenol/phenate** 1.21%/1.93%___*May cause cosmetic and functional damage; **efficacy not verified
New FDA-Cleared Sterilants “Old” > 2% Glut, 7.5% HP, 1.0% HP and 0.08% PA
New 1.21% glut and 1.93% phenol/phenate (HLD-20 m at
25oC) 0.55% ortho-phthalaldehyde (HLD-12 m) 7.35% HP and 0.23% PA (HLD-15 m) 2.5% Glut (HLD-5 m at 35oC) Hypochlorite (650-675ppm free chlorine)
Ensure antimicrobial activity and material compatibility
Ideal HLD/Chemical Sterilant Rapid HLD (< 10 min) No disinfectant residue after rinsing Excellent material compatibility Long shelf-life Nontoxic (no odor or irritation issues) No disposal problems Monitor minimum effective concentration
Glutaraldehyde Advantages Numerous use studies published Relatively inexpensive Excellent materials compatibility
Disadvantages Respiratory irritation from vapor Pungent and irritating odor Relatively slow mycobactericidal activity Coagulate blood and fix tissues to surfaces Allergic contact dermatitis
Ortho-phthalaldehyde
Advantages Fast acting HLD No activation Excellent materials
compatibility Not a known irritant to
eyes and nasal passages
Weak odor No ACGIH or OSHA limit
Disadvantages Stains protein gray Cost ($30/gal); but lower
reprocessing costs-soak time, devices per gal
Slow sporicidal activity Hypersensitivity in some
patients with a history of bladder cancer
Comparison of Glutaraldehyde and OPA>2.0% Glutaraldehyde HLD: 45 min at 25oC Needs activator 14 day use life 2 year shelf life ACGIH ceiling limit,
0.05ppm Strong odor MEC, 1.5% Cost - $12/gallon
0.55% Ortho-phthalaldehyde HLD: 12 min at 20oC No activator needed 14 day use life 2 year shelf life No ACGIH or OSHA limit Weak odor MEC, 0.3% Cost - $30/gallon
OPA Research Alfa and Sitter, 1994. OPA eliminated all
microorganisms from 100 different endoscopes used in a clinical setting.
Gregory et al, 1999. OPA achieved a 6 log10 reduction of M. bovis in 5.5 min compared to 32 min for glutaraldehyde
Walsh et al, 1999. OPA effective against glutaraldehyde-resistant M. chelonae strains
OPA Label Claims Worldwide
1. Europe, Asia, Latin America5 min at 20oC
2. Canada and Australia10 min at 20oC
3. United States12 min at 20oC
1. Antimicrobial tests support 5 min exposure time.
2. Canadian regulatory authority requires 6-log reduction in mycobacteria (5.5 m) and only 5 min intervals.
3. FDA requires 6-log reduction of mycobacteria suspended in organics and dried onto scope without cleaning
Ortho-phthalaldehyde (OPA)New Contraindications for OPA
Repeated exposure to OPA, following manual reprocessing of urological instruments, may have resulted in hypersensitivity in some patients with a history of bladder cancer undergoing repeated cystoscopy.
Out of approximately 1 million urological procedures, there have been reports of 24 patients who have experience ‘anaphylaxis-like’ reactions after repeated cystoscopy (typically after 4-9 treatments).
Risk control measures: residues of OPA minimized; and contraindicated for reprocessing of urological instruments used on patients with history of bladder cancer.
Minimum Effective Concentration (MEC)High Level Disinfectant (HLD)
Dilution of HLD occurs during use Test strips are available for monitoring MEC For example, test strips for glutaraldehyde
monitor 1.5% Test strip not used to extend the use-life beyond
the expiration date (date test strips when opened)
Testing frequency based on how frequently the solutions are used (used daily, test at least daily)
Record results
Hazardous Component The active ingredient is glutaraldehyde. CIDEX 14-day solution contains 2.4% CIDEX 28-day solution contains 3.2%
Routes of Exposure
Absorption Most common route of exposure for
Cidex Inhalation Ingestion Injection
Effects of Acute Exposure to Glutaraldehyde Inhalation – Low to mild irritant; nose and throat
irritation, nausea & headaches Eye Contact – Vapors irritating to eyes & may
cause eye damage on contact Skin Contact/Absorption – Mild to moderate
irritant. Ingestion – Toxic. Irritation if consumed in small
amounts; Toxic effects similar to alcohol poisoning; including CNS depression, nausea & vomiting if consumed in large amounts
Effects of Acute Exposure (Continued)
Chronic Exposure – repeated skin contact may cause dermatitis
Sensitization to Product – Limited evidence to support possible skin and respiratory sensitization
NO reported evidence of carcinogenicity. Glutaraldehyde is metabolized in the body predominantly to carbon dioxide and is exhaled via the respiratory tract. There is little potential for accumulation of the product in the body.
How EH&S Monitors Employee Exposure An Assay Technology ChemDisk Monitor for
aldehydes is worn on the lapel to represent the breathing zone for no less than 15 minutes or the duration of the procedure.
The disk is collected and sent to AIHA accredited lab for testing.
A report of the results is distributed to the supervisor and employee.
Exposure Monitoring
Initial monitoring Annual monitoring Periodic monitoring; where initial results are
above the TLV-C or there is a change in procedure.
Employee Exposure to Glutaraldehyde
ACGIH TLV-C 0.05 ppm, instantaneous limit NIOSH REL 0.2 ppm TWA for 10 hours OSHA does not have a PEL
ACGIH TLV-C Threshold Limit Value-Ceiling (TLV-C) is the
concentration that should not be exceeded at any time when working with glutaraldehyde or glutaraldehyde containing products.
EH&S compares your exposure to the TLV-C.
Protective Work Clothing and Equipment Nitrile rubber or butyl rubber gloves Splash-proof safety goggles with side shields Lab coat
Personal Protective Equipment
Face Shield OR Safety glasses with a general surgical mask to protect eyes & mucus membranes
Nitrile gloves with long cuffs Cover gowns – waterproof to protect clothing
from splashes Respirators may be used, but not required. N-95
are ONLY used during endoscopic procedures on patients requiring airborne isolation. N-95 masks are not to be used while performing high level disinfection.
Engineering Controls Room large enough to ensure
adequate dilution of vapors 10 Air changes per hour Exhaust that pulls vapors away
from the user’s breathing zone Fresh air entering at ceiling Routine maintenance of system OR ductless fume ventilation
devices that contain filters to absorb glutaraldehyde vapors from the air
Examples of Ductless Fume Ventilation Devices that contain filters to absorb glutaraldehyde vapors from the air
Management of Glutaraldehyde Spills or Leaks
Stop discharge and contain spill Keep others at a safe distance Don PPE ASAP Absorb any product with an inert absorbent
or use absorbent paper to pick up all liquids Seal absorbent paper along with any
contaminated clothing in a vapor-tight plastic bag and place in biohazardous container.
Call Operation of Plant to assist with large spills
Waste Disposal Discard remaining solution in container
down sink drain Flush well with large quantity of water. For
every 1-qt of CIDEX use 2-gal of water. Rinse container well with water Put container in trash can DO NOT
reuse empty container
Storage Requirements for Glutaraldehyde Keep containers tightly closed Room temperature between 59-86oF Store in a cool dry, well ventilated area (not under sinks!) Do not store with acids, alkalines or oxidizers Do not store with incompatible products Protect containers from damage Avoid skin & eye contact (don’t store the bottle above
eye level) No food or drink in the area
Secondary Containers The name of the chemical without
abbreviations and symbols The name of the responsible party The expiration date The hazard class
Example:
First Aid Skin – wash skin with soap & water Eyes – Use emergency eyewash station to
flush eyes for 15 min Inhalation – move to fresh air
After first aid is given, follow-up with Employee Health Services as needed or Emergency Care Center if after hours
Manual Cleaning Meticulous manual cleaning of all instruments
must precede exposure to any high-level disinfectant or sterilant. Inadequate cleaning of instruments has been one factor cited in transmission of infection by flexible endoscopes.
Appropriate cleaning reduces the number of microorganisms by 99.9%.
Always follow the manufacturer’s guidelines for design features that are unique to a particular instrument