Infection Control Nursing Officer
Infection Control Unit
Teaching Hospital
Jaffna.
1
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
3
 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 items
 2. Semicritical/ intermediate risk items
 3. 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 microorganisms, hence low risk of disease transmission

Thorough cleaning is adequate with low level
disinfection as necessary
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Factors influence the
sterilization process
 The temperature of sterilization
 The period of sterilization
 Inactivation by organic matter
 Whether the article was cleaned before sterilization
 The sterilization cycle can be divided into three
periods:
 a.Heating up period
 b. Holding period
 c. Cooling period
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Objective
To
reduce hospital associated
infections and protect patients,
employees, health care students
and visitors.
The functional flow of activities in
CSSD
 RINSING
 CLEANING
 DRYING
 INSPECTION AND ASSEMBLY
 PACKAGING
 LABELLING
 STERILIZATION
 STORAGE
 DISTRIBUTION
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
disinfection or sterilization.
to
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.
LABELLING
Each 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.
STORAGE
Should
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




1.
2.
3.
4.
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 sterilization
Steam – saturated and dry steam without air
Pressure – 2.4 bar / 15lb
Temperature – 1210C
Time - 20 min
Autoclaving at 1210C at 15 lb pressure
for 20 min is acceptable for routine
hospital use
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Moist heat sterilization…
Advantages
 Non toxic
 Inexpensive
 Rapid action
 Good penetration ability
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Sterilization by dry heat
 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
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Sterilization by dry heat
 Total cycle may be several hours, hence hot air ovens
should have
 Time lock on the door - items cannot be added or
removed during, the cycle
 Fan 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 sterilization
 Mechanical indicators – Observe the machine's dials and
gauges - temperature, pressure, time
 Chemical indicators – changes colour on exposure to the
appropriate sterilization cycle
Autoclave 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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Storage
 Once 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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Disinfection
Methods
 Heat –
 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 & Sterilization
 2% 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 disinfection
 Objects that cannot be heat-treated, should be
disinfected by chemicals
 Clean the article before disinfection
 Dilution of concentrates should be accurately
measured
 Consider the range of activity, toxicity and cost
 Beware of inactivating substances
 Use fresh disinfectant solutions
 Use clean containers
 Never 'Top up' disinfection containers
 Item 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 disinfection
 Range of activity
 Satisfactory contact
 Concentration
 pH- alkaline for gluta. and acid for phenols
 Neutralization- organic matter, hard water, soap
 Stability
 Speed of action- high-hypochlorite
 Cost
 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)
_
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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
Orthophthalaldehyde
(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 items
High risk
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 needles
IV Infusions
Radiation
Endoscopes
(1) 2%
glutaraldehyde for 20
min.
(2)0.34%peracetic
acid-:10min
Thereafter, rinse
scope and channels
with sterile water
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Intermediate risk -High level disinfection
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 thoroughly
Dry & wipe over with 70% alcohol
Airways
Ambu bag
Tubing
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.
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Low risk- cleaning and low level disinfection
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
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Management of a blood spill
 Wear heavy duty gloves
 Soak the spill with an absorbent material
 Cover with 1% Sodium hypochlorite
 Leave for 20 minutes
 Clean
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Take home message
In failure of sterilization and disinfection
 Increase morbidity and mortality
 Longer hospital stay
 Expensive antibiotics
 Increase work load- doctors, nurses, laboratory
 Extra cost to the state!
Apply your knowledge appropriately
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THANK YOU
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