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Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical DevicesDevices
•• John Harrison John Harrison MBE. MBE. MIDScMIDSc
•• Sterile Services Sterile Services ManagerManager
ROYAL WELSH SHOWGROUNDROYAL WELSH SHOWGROUND
BUILTH WELLSBUILTH WELLS3131stst October 2007October 2007
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical DevicesDevices
WATER ISWATER IS VITALVITAL TO THE CLEANING PROCESSTO THE CLEANING PROCESS
UNIVERSAL SOLVENTUNIVERSAL SOLVENT
-- carrier of the detergent to the surface of a devicecarrier of the detergent to the surface of a device
-- carrier of the soil/contaminants from the surfacecarrier of the soil/contaminants from the surface
The unique properties of water are related to its structureThe unique properties of water are related to its structure
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical DevicesDevices
Polarity of the water molecule lends itself
to the unique properties of water
Hydrogen atoms (the positive charge) from one water molecule can bond (hydrogen
bond) with the oxygen atom (negative charge) from another water molecule
Combined total forces of the bonds give watersurface tension
Water, ItWater, It s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices Problems:Problems:
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?
Ensure that adherent infectious agents are removed together
with the organic matter that protects them
Ensure better contact between the disinfectant and any
remaining infectious agents that may be present on surfaces ofdevices being processed
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?
Ensure instrument function
Heat and some disinfectants (alcohols and aldehydes) are tissue
fixatives and may cause moving parts of a device to stiffen if
surfaces are not thoroughly cleaned before sterilisation/disinfection
Clinically Relevant SoilsClinically Relevant Soils
Problem occurs when:Problem occurs when:
blood is allowed to dry on the instrumentsblood is allowed to dry on the instruments
when heated, blood becomes insoluble when heated, blood becomes insoluble (heat causes blood to denature(heat causes blood to denature
Dried blood on the surface
with fibrins tightly
attached to the surface
Fibrin
Magnified surface
of metal device
Surface of
metal device
Water, ItWater, It’’s Quality and Decontamination s Quality and Decontamination of Medical Devices of Medical Devices
WHY IS CLEANING NECESSARY?
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?
Ensure that adherent infectious agents are removed together
with the organic matter that protects them
ORGANIC MATTER
INFECTIOUS AGENTSURFACE
MICRO ORGANISMSMICRO ORGANISMS––
Definition: Living entity (organism) of microscopic Definition: Living entity (organism) of microscopic or subor sub--microscopic sizemicroscopic size
HIV virus
Mycobacterium
tuberculosis
Cryptosporidium
Malaria
parasite
Yeast
Flu-virus
SARS
virus
Water, ItWater, It s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?
Water, ItWater, It s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?•• Source of all life forms.Source of all life forms.
–– Potable Water Not sterile.Potable Water Not sterile.–– Cause of infectionsCause of infections
•• LegionellaLegionella•• Pseudomonas Pseudomonas •• Tuberculosis ++Tuberculosis ++
–– NEED TO ESTABLISH AND MAINTAIN SYSTEMS THAT NEED TO ESTABLISH AND MAINTAIN SYSTEMS THAT WILL PERMIT SAFE PRODUCTS TO BE PRODUCED FROM WILL PERMIT SAFE PRODUCTS TO BE PRODUCED FROM THE DECONTAMINATION FACILITY THE DECONTAMINATION FACILITY
NATURAL CONTAMINANTS OF WATERNATURAL CONTAMINANTS OF WATER
Minerals: Solid –organic:
- Calcium -Algae
- Magnesium -Fungi
- Iron -Bacteria
- Sulfates
- Chlorides
- Silica
-Organics Solid inorganic-Humic acid -Silt
-Tannin -Rust
-Pyrogens -Floc-Clays
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?
FACTORS AFFECTING CLEANINGFACTORS AFFECTING CLEANINGSOIL TYPE
PRE-TREATMENT
CLEANER (CHEMISTRY)
(DETERGENT)
WATER - QUALITY
WASHER/DISINFECTOR
Water, ItWater, It’’s Quality and s Quality and Decontamination of Medical Decontamination of Medical Devices Devices WHY IS WHY IS CLEANINGCLEANING NECESSARY?NECESSARY?FACTORS AFFECTING CLEANINGFACTORS AFFECTING CLEANING
TYPE
Clinically Relevant Soils
3 SOIL TYPES
• Organic: fat, grease, proteins, carbohydrates and
micro organisms
• Inorganic: rust, scale (hard water deposits),
residues from cleaners
• Combination: organic + inorganic example - bone
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices WHY IS CLEANING NECESSARY?WHY IS CLEANING NECESSARY?FACTORS AFFECTING CLEANINGFACTORS AFFECTING CLEANING
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices FACTORS EFFECTING CLEANING FACTORS EFFECTING CLEANING
-WHAT IS A SURFACTANT?
-SURFACTANT = SURFACE ACTIVE AGENT
- Agents which change the properties of water by lowering the
surface tension of water, allowing the cleaner to penetrate soil and
surface irregularities
- Emulsify oily soils keeping them dispersed and in suspension
Surfactant moleculeSurfactant molecule
1) A hydrophilic or ‘water loving’ head
(Hydrophile)
2) A hydrophobic or ‘water hating tail
Amphi ‘double’
Philos ‘affinity’
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices
BASIC WATER CYCLE
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Therefore:Therefore:There is a need to know the quality of the raw waterThere is a need to know the quality of the raw water
And:And:There may be a need to improve qualityThere may be a need to improve quality
And:And:
There There willwill be a need to continuallybe a need to continually monitor the quality of the monitor the quality of the purification systempurification system
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Important factorsImportant factors
-pH
- Water Hardness
- Conductivity/metal ion content
- Alkalinity
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Factors affecting waterFactors affecting water
pHFrench term ‘pouvoir
hydrogene’ or
Hydrogen Power
•Ca2+ and Mg2+ ions make up the hardness
•CO2- creates the alkaline environment
•Alkalinity lowers cleaning efficacy and results in the formation of lime scale
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices
Important factorsImportant factors
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Hardness:Hardness:
••Affects efficiency of disinfectantAffects efficiency of disinfectant••May leave deposits on devices May leave deposits on devices
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Hardness:Hardness:For cleaning, hardness should be less than For cleaning, hardness should be less than
50ppm50ppmBut:But:
As softening does not improve quality, As softening does not improve quality, excessive softening will lead to deposits on excessive softening will lead to deposits on
devicesdevicesSo:So:
Additional purification may be requiredAdditional purification may be required
Flow
Water hardnessSoftener resin
Sodium
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Important factorsImportant factors
Treatment:Water softening removes molecules involved in hardness of water
It does not reduce the OVERALL salt content
It does not remove chlorides or silicates
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Water: Softening PlantWater: Softening Plant
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Ionic contamination:Ionic contamination:
••Create cosmetic changes to flexibleCreate cosmetic changes to flexible
endoscopesendoscopes
••May lead to more serious damageMay lead to more serious damage
••May provide a habitat for microMay provide a habitat for micro
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Ionic contamination:Ionic contamination:
If this is high then purification will If this is high then purification will be required:be required:
Limits are given in HTM 2030Limits are given in HTM 2030
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Microbiological contamination:Microbiological contamination:
Contravenes the purpose of Contravenes the purpose of decontaminationdecontamination
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Microbiological contamination:Microbiological contamination:
This This willwill be removed by purificationbe removed by purification
Weekly TVC limits of postWeekly TVC limits of post--disinfection rinse water disinfection rinse water for for AERsAERs is,is, 0 cfu/100ml0 cfu/100ml
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Important factorsImportant factorsWhat is ConductivityWhat is Conductivity
FACTORS EFFECTING CLEANING – WATER QUALITY
Conductivity is the ability of a water solution to conduct electricity
(measure of how much (not what) material is dissolved in water)
Parameter used to measure relative purity of water (µS/cm)
(2µS/cm is classed as high purity)
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Bacterial Bacterial endotoxinsendotoxins::••Can create toxic shockCan create toxic shock••Serious patient reactionSerious patient reaction••Patient deaths ?Patient deaths ?
What Are Endotoxins ?What Are Endotoxins ?
•• EndotoxinsEndotoxins are part of the outer are part of the outer membrane of the cell wall of Grammembrane of the cell wall of Gram--negative bacteria. Endotoxins are negative bacteria. Endotoxins are invariably associated with Graminvariably associated with Gram--negative negative bacteria whether the organisms are bacteria whether the organisms are pathogens or not. Although the term pathogens or not. Although the term "endotoxin" is occasionally used to refer to "endotoxin" is occasionally used to refer to any cellany cell--associated bacterial toxin, it is associated bacterial toxin, it is properly reserved to refer to the properly reserved to refer to the lipopolysaccharidelipopolysaccharide complex associated complex associated with the outer membrane of Gramwith the outer membrane of Gram--negative bacteria such as negative bacteria such as E. coliE. coli, , SalmonellaSalmonella ShigellaShigella PseudomonasPseudomonas
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Bacterial Bacterial endotoxinendotoxin contamination:contamination:This may be removed by purification or may This may be removed by purification or may
need additional need additional endotoxinendotoxin filtrationfiltration
Limits in HTM 2030 are <=0.25 EU/mlLimits in HTM 2030 are <=0.25 EU/ml
Does this apply to nonDoes this apply to non--invasive (?) invasive (?) endoscopyendoscopy procedures?procedures?
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
Purification methods:Purification methods:••Softening Softening –– may not be sufficientmay not be sufficient••Demineralisation Demineralisation –– may lead to microbemay lead to microbepasspass--throughthrough
••Reverse Osmosis Reverse Osmosis –– preferred method butpreferred method butmay require prior softeningmay require prior softening
••Distillation Distillation –– unnecessaryunnecessary
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices
Water is removed
from the impurities
- create water vapour
- passed down a column
(condenser)
- vapour changes back to
liquid and collects as
distillate
Distillation Removes:
- most inorganic solids
- all organics with a BP >
than water (>100ºC)
- all bacteria
Water Treatment:Distillation
Water FiltrationWater Filtration
Water: FiltrationWater: Filtration
•• 5um 1um 0.22um5um 1um 0.22um
PRINCIPLES OF OSMOSIS PRINCIPLES OF OSMOSIS
Water flows from less concentrated
solution, through a semi-permeable
membrane, to a concentrated saline
solution
Membrane
Osmotic Pressure
Osmotic Flow
REVERSE OSMOSIS (RO)REVERSE OSMOSIS (RO)External pressure is applied to reverse External pressure is applied to reverse the natural osmotic flowthe natural osmotic flowResulting in removal of particlesResulting in removal of particlesfrom the solutionfrom the solution
Less corrosive to steel and copperLess corrosive to steel and copper
Membrane
Flow
Pressure > Osmotic Pressure
RO removes
- bacteria/pyrogens
- salts
- sugars
- proteins
- particles
- dyes
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
••
Water Water Decontamination of Medical DevicesDecontamination of Medical Devices
Water: Water: Decontamination of medical DevicesDecontamination of medical Devices
Testing Testing AERsAERs::Weekly:Weekly: hardnesshardness
conductivityconductivityTVCTVC
Annually:Annually: chemical purity (10 chemical purity (10 parameters)parameters)
bacterial bacterial endotoxinsendotoxinsTVCTVCEnvironmentalEnvironmental mycobacteriamycobacteria
Water: Water: Decontamination of medical DevicesDecontamination of medical Devices10 parameters for annual testing 10 parameters for annual testing
•• AppearanceAppearance•• pHpH•• Total dissolved solidsTotal dissolved solids•• HardnessHardness•• Chloride Chloride
•• ConductivityConductivity•• Heavy metals Heavy metals •• IronIron•• PhosphatePhosphate•• SilicateSilicate
Water, ItWater, It’’s Quality and Decontamination of Medical s Quality and Decontamination of Medical Devices Devices Factors affecting cleaningFactors affecting cleaning
AGITATION:
-physical agitation from water spray
brings fresh cleaning solutions to
the soiled instruments, washes
away used-up detergents
(spray loosens blood with physical
impact)
- spray from different angles
helps prevent blocking
from piled up instruments)
What Quality of Water is Required What Quality of Water is Required for Washing and for Washing and RinsingRinsing ??
Bacteria Free WaterBacteria Free Water&&
Endotoxin Free WaterEndotoxin Free Water
Are required for both Surgical Are required for both Surgical Instrument Washers and Automated Instrument Washers and Automated
Endoscope ReEndoscope Re--ProcessorsProcessors
Water: Water: Decontamination of Medical DevicesDecontamination of Medical Devices
•• Qualities required:Qualities required:
•• Manual cleaning:Manual cleaning: Softened Potable WaterSoftened Potable Water•• AWD Pre Wash with chemistries: Softened Potable waterAWD Pre Wash with chemistries: Softened Potable water•• Main wash with chemistries: Softened Potable WaterMain wash with chemistries: Softened Potable Water•• RinseRinse RO waterRO water•• Rinse and thermal disinfection: RO waterRinse and thermal disinfection: RO water
Maintaining RO quality: Maintaining RO quality: filtered, heated (min 60C), filtered, heated (min 60C), re circulated, UVre circulated, UV-- disinfected (AEWD)disinfected (AEWD)
disinfection of RO with Chlorine if mordisinfection of RO with Chlorine if more than 6ppm e than 6ppm chlorine potential for damage of membrane unit cuts out once 30 chlorine potential for damage of membrane unit cuts out once 30 ((µµS/cm)S/cm) reached.reached.
Where/How Do We Generate This Where/How Do We Generate This Quality of WaterQuality of Water
•• Buy in as Buy in as ““Sterile Water for irrigationSterile Water for irrigation”” ––No EndotoxinsNo Endotoxins
•• Buy in as Buy in as ““Sterile Water for InjectionSterile Water for Injection”” ––No EndotoxinsNo Endotoxins
•• Basic micro filtration Basic micro filtration –– Endotoxins PresentEndotoxins Present•• Ultrafiltration Ultrafiltration –– No endotoxinsNo endotoxins•• NanoNano filtration filtration –– No EndotoxinsNo Endotoxins•• Reverse osmosis Reverse osmosis –– No EndotoxinsNo Endotoxins
Water RO Maintenance Costs:Water RO Maintenance Costs:
•• Cost to company for call outs and set Cost to company for call outs and set visits visits ££23,130.0023,130.00papa
•• In House Maintenance costs In House Maintenance costs ££7000.00pa7000.00pa•• Water testing costs @Water testing costs @££13.00 per test x 4 13.00 per test x 4
machines in machines in EndoscopyEndoscopy ==££3000.00pa3000.00pa•• Totals = minimum Totals = minimum ££33,000.00pa33,000.00pa
THANK YOU FOR YOUR TIMETHANK YOU FOR YOUR TIME