Infection Control Nursing OfficerInfection Control Unit

Teaching HospitalJaffna.

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Definition of terms

Sterilization – complete elimination or destruction of all forms of microbial life (including spores)

Disinfection – elimination of micro-organisms on inanimate objects with the exception of bacterial spores

Antisepsis – prevention of infection of tissues and body surfaces by application of germicides

Cleaning – the removal of visible soil (eg; inorganic and organic material) from objects and surfaces

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Disinfection and sterilization practices are essential for ensuring that medical and surgical instruments do not transmit infectious pathogens to patients

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Instruments and items for patient care are divided into 3 categories based on the degree of risk of infection involved in the use of the items

1. Critical/ high risk items2. Semicritical/ intermediate risk items3. Non critical/ low risk items

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1. Critical / high risk items

Objects that enter sterile body tissue or vascular system

Any microbial contamination could result in disease transmission

Must be sterile

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2. Semi-critical / intermediate risk items

Items that come in contact with intact mucous membranes

Generally resistant to infection by common bacterial spores but susceptible to other micro-organisms

Need not be sterile; disinfection acceptable

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3. Non-critical / low risk items Items that come into contact with intact skin

but not mucous membranes

Intact skin is an effective barrier to most micro-organisms, hence low risk of disease transmission

Thorough cleaning is adequate with low level disinfection as necessary

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Factors influence the sterilization processThe temperature of sterilization The period of sterilizationInactivation by organic matterWhether the article was cleaned before

sterilization The sterilization cycle can be divided into

three periods:a.Heating up periodb. Holding periodc. Cooling period

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ObjectiveTo reduce hospital associated infections and protect patients, employees, health care students and visitors.

The functional flow of activities in CSSD

RINSINGCLEANINGDRYINGINSPECTION AND ASSEMBLYPACKAGINGLABELLINGSTERILIZATIONSTORAGEDISTRIBUTION

RINSING

Rinsing of articles after use should not be permitted in patient care areas unless carried out by a trained member of the staff.

CLEANING

All reusable medical devices should be thoroughly cleaned prior to disinfection or sterilization.

DRYING

All articles should be dried appropriately

INSPECTION AND ASSEMBLY

Each item should be inspected for functionality, defects, breakage and then appropriately assembled.

PACKAGING

Articles should preferably be packed in porous material.

LABELLINGEach pack should be marked with nomenclature of the article, contents of the pack, initials of the person who packed it, date and initials of the person who carried out the sterilization.

STORAGEShould be properly managed separately for sterile and non-sterile stores. For sterile goods, clean room conditions should be followed.

Sterile pack should be stored 20-25 cm from the floor, 45-50 cm from the ceiling, 15-20 cm on out side of the wall.

DISTRIBUTION

Refers to clean and dirty articles exchange system. A program should be established for the collection of used items from patient care areas and distribution of sterilized goods.

Moist heat sterilization Moist heat kills microorganisms by coagulating

and denaturing enzymes and structural proteins

Applied in the form of steam Steam under pressure is used to achieve a

higher temperature 4 parameters of steam sterilization1. Steam – saturated and dry steam without air2. Pressure – 2.4 bar / 15lb3. Temperature – 1210C

4. Time - 20 min

Autoclaving at 1210C at 15 lb pressure for 20 min is acceptable for routine hospital use 20

Moist heat sterilization…

Advantages Non toxic Inexpensive Rapid action Good penetration ability

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Sterilization by dry heat

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Dry heat penetrates less well and is less effective than moist heat

Consequently, higher temperatures and longer periods are required for sterilization with dry heat

 Used for sterilization of -sharp cutting instruments and -laboratory glass wear -powder, oil

Sterilization by dry heatTotal cycle may be several hours, hence hot

air ovens should have Time lock on the door - items cannot be added

or removed during, the cycleFan to distribute the heat evenly

Dry heating at 1600C for for 2 hours is acceptable for routine

hospital use

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Monitoring of sterilizationMechanical indicators – Observe the machine's

dials and gauges - temperature, pressure, timeChemical indicators – changes colour on

exposure to the appropriate sterilization cycleAutoclave strips Bowie Dick test

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Monitoring of sterilization…Biological indicators – bacterial spores

which require high temperatures to lose viability – spore strips, self contained vials

Geobacillus stearothermophilus – for steam or chemical vapor sterilization

Bacillus subtilis -for dry-heat or ethylene oxide gas sterilization

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StorageOnce sterilized, the instruments should be

maintained in a sterile state until they are used again

Improper storage would result in a break of the 'chain of Sterility'

The expected 'shelf-life' of a sterile package is depend on the type of area in which it is stored and the material used for packaging

A closed, protected area with a minimal airflow such as a cabinet or drawer that can easily be disinfected is preferable to an open stacking system

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DisinfectionMethodsHeat –

Pasteurization - 63-66 0C for 30 min 72 0C for 15 sec. (the flash method)

Boiling - bacterial spores can survive

Physical – ultrasonic, UV radiation - used for

removing debris (cleaning) prior to autoclaving

 Chemical

Disinfectant used for one purpose may not be equally effective for another

The antimicrobial activity falls in the presence of organic debris

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Disinfection & Sterilization2% Glutaraldehyde (cidex)

- 2% Alkaline solution- Needs activation- Sterilization time – 10 hours- Disinfection time – 20 mins- Activated solution – 2 weeks/20 times- Sterilization/HLD of heat sensitive items - Irritant to skin, eyes & respiratory tract - Should be handled in a well ventilated area- Should wear protective clothing

- Fixation of protein

Disinfection & Sterilization (cont.)Para Safe

- Combination of per oxygen compound, activator & stabilizer- Non-corrosive- Non-irritant to skin- Eye irritation - No toxic residues- Expensive- Stable for 24 hours only

Disinfection & Sterilization (cont.)Chlorine releasing agents

- Sodium hypochlorite, Calcium hypochlorite, Chlorine granules- Active against bacteria, viruses, fungi & some spores- Less active against mycobacteria - Contact time 20-30 mins - Rapidly inactivated by organic matter- Corrosive to metal - Do not add powder to water- Avoid contact with acid/acidic body fluids e.g.- urine- Avoid contact with skin, eyes & mucus membrane - Unstable - daily preparation is necessary - Blood & body fluid spillages – 1% solution (10000 ppm) - General environmental cleaning – 0.1% (1000 ppm)

Disinfection & Sterilization (cont.)Alcohol

- 70% - 90% Ethyl alcohol/ Isopropyl alcohol- Rapidly active against vegetative bacteria & mycobacteria - Viruses – variable activity - Not sporicidal - Only on clean surfaces - Disinfection of items that cannot be immersed in other disinfectants e.g.- electric equipment- Skin anti-sepsis

Disinfection & Sterilization (cont.)Chlorhexidine – 4%-5% (Hibiscrub/Hibitane)

- Active against Gram positive organisms & fungi- Poorly active against Gram negative organisms- Non toxic- Good residual activity- Pre operative skin disinfection/Surgical hand washing- Savlon – 1.5% Chlorhexidine + 15% Cetrimide Poor bactericidal activity

Disinfection & Sterilization (cont.)Chlorhexidine – 4%-5% (Hibiscrub/Hibitane)

- Active against Gram positive organisms & fungi- Poorly active against Gram negative organisms- Non toxic- Good residual activity- Pre operative skin disinfection/Surgical hand washing- Savlon – 1.5% Chlorhexidine + 15% Cetrimide Poor bactericidal activity

Principles of disinfectionObjects that cannot be heat-treated, should be

disinfected by chemicalsClean the article before disinfectionDilution of concentrates should be accurately

measuredConsider the range of activity, toxicity and costBeware of inactivating substances Use fresh disinfectant solutionsUse clean containersNever 'Top up' disinfection containersItem should kept in contact with the disinfectant

for the required time period and no longer than that

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Chemical disinfectants…Factors affecting the effectiveness/usefulness

of chemical disinfectionRange of activitySatisfactory contactConcentrationpH- alkaline for gluta. and acid for phenolsNeutralization- organic matter, hard water,

soapStabilitySpeed of action- high-hypochloriteCost Potency- high, intermediate, low Lack of adverse effects

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Commonly used disinfectants

Antimicrobial activity

Disinfectant Vegetative bacteria

mycobacteria virus spores

Glutaraldehyde + + + +Hypochlorite + + + +Phenolics + + +(poor) _Alcohol + +(limited) + _Chlorexhidine + _ _ _Povidone-iodine + +(prolong

contact)+ +/-

QAC + _ +(limited) _ 37

Chemical agents used as high-level disinfectants

High level disinfectant

Advantages Disadvantages

Glutaraldehyde (2%)

Relatively inexpensive

Excellent material compatibility

Needs activation

Respiratory irritation

Allergic contact dermatitis

Irritating odor

Hydrogen peroxide (3%)

No activation required

Enhance removal of organic matter and organisms

No odor or irritation

Corrosive

Eye damage with contact

Ortho-phthalaldehyde (0.55%)

Fast acting

No activation required

Good material compatibility

No odor

Stains skin, MM, clothing and environmental surfaces

Expensive

Eye irritation

Peracetic acid (0.2-0.35%)

Good material compatibility

Fully automated system

Environmental friendly by-products

Effective in the presence of organic matter

Expensive

Unstable

Small no. of items only per cycle

Serious eye and skin damage on contact

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Sterilizing medical itemsHigh risk

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Surgical instruments, lumber puncture sets, surgical dressings, surgical protective clothes, rubber gloves, soiled or fouled linen, Tracheostomy tubes

Autoclave

Cannulae & catheters, Prosthesis Nasogastric tubes, endothracheal tubes, syringes and needlesIV Infusions

Radiation

Endoscopes (1) 2% glutaraldehyde for 20 min. (2)0.34%peracetic acid-:10min Thereafter, rinse scope and channels with sterile water

Intermediate risk -High level disinfection

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Thermometer Wipe with 70% alcohol swab & store dry

Vaginal speculem Tongue depressor Proctoscope

Wash with detergent & water and boil for 20 minutes(In high risk patients - autoclave)

Respiraotry equipment; Eg: Masks

Wash thoroughlyDry & wipe over with 70% alcohol

AirwaysAmbu bagTubing

Disinfect by heat or using 2% glutaraldehyde for 30 min.After immersing in glutaraldehyde, rinse thoroughly in sterile water

Nebulizer Use sterile water for nebulization Clean with detergent and hot water after each patient. Tubing can be immersed in 2% glutaraldehyde for 30 min.

Low risk- cleaning and low level disinfection

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Floors  Mop with hot water & detergent

Walls Clean with hot water & detergent

Cutlery & crockery Liquid detergent & hot water

Linen All hospital laundry must be heat disinfected

Bed pans, urinals Empty the contents into toilet. Fill the utensil with phenolics, leave for 5min. & wash with water

Management of a blood spillWear heavy duty glovesSoak the spill with an absorbent materialCover with 1% Sodium hypochlorite Leave for 20 minutes Clean

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Take home messageIn failure of sterilization and disinfection

Increase morbidity and mortalityLonger hospital stayExpensive antibioticsIncrease work load- doctors, nurses, laboratoryExtra cost to the state!

Apply your knowledge appropriately43

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