water, it’s quality and decontamination of medical · pdf filewater, it’s quality...

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 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


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


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?


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


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


Important factorsImportant factors


Hardness:Hardness:

••Affects efficiency of disinfectantAffects efficiency of disinfectant••May leave deposits on devices May leave deposits on 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


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


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


Microbiological contamination:Microbiological contamination:

Contravenes the purpose of Contravenes the purpose of decontaminationdecontamination


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)


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


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?


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 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

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


•• 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

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