SANITATION, STERILIZATION, DISINFECTION
LECTURE NOTES
PURPOSE OF HOSPITAL ASEPSIS:
1. Provide an environment that is as close to germ-free as possible.
2. Protect patients and hospital personnel from airborne pathogen, contact pathogens
and bloodborne pathogens.
3. Prevent any introduction of microorganisms to patients or staff by adhering to strict
standards of medical asepsis in the surgical OR and for the surgical items including
instruments, equipment and supplies.
a. Reduce bioburden created by surgical intervention
b. Reduce possibility of surgical patient cross-contamination
c. Prevent nosocomial infections in subsequent surgical patients
4. Maintain infection free surgical wounds by containing contamination via tissue
handling or wound closure through surgical asepsis.
PRINCIPLES FOR CONTAMINATION PREVENTION ON LIVING AND INANIMATE
OBJECTS:
1. Aseptic technique – containment of microbial contamination on animate (living)
surfaces via mechanical and/or chemical means
a. Sanitization – a means of reducing microbes
b. Antisepsis – infection prevention through the inhibition of microbial growth.
Because antiseptics are using on animate objects they must be weaker than
disinfectants which are used on inanimate objects.
2. Sterile Technique – Prevention of microbial contamination on inanimate surfaces via
mechanical, chemical, thermal or nuclear means. Selecting a sterilization method and
agent depends on multiple variables such as cost and nature of the item
(submersible/nonsubmersible, heat-sensitive/non-heat sensitive).
a. Disinfection – the process of destroying all microorganisms, except spore
bearing ones.
b. Sterilization – the process of destroying all microorganisms including
viruses, fungi and fungal spores and all forms of bacteria and their spore by
using sterilant or sporicidal agents.
LEVELS OF CONTAMINATION PREVENTION:
1. LEVEL 1 – High level asepsis for critical items; required for any items introduced to
internal body areas or areas with high risk of infection if contaminated with
microorganisms, including bacterial spores.
2. LEVEL 2 – Intermediate asepsis for semi-critical items; used for those items that
contact mucous membranes or broken skin.
3. LEVEL 3 – low level or non-critical items; used for those items that contact intact
skin only.
SURGICAL SUPPLY PREPARATION PHASES:
1. Decontamination or cleaning phase – Level 3 process for removing initial gross
contaminants such as blood and debris from surgical instruments; for non-critical
items, this is the only phase required before restocking
a. Pre-rinse or soaking – initial immersion in a soak basin to loosen gross
contaminants from instruments in a prepared detergent or distilled water
solution
b. Washing – a function performed away from the OR in processing room prior
to reaching decontamination room
i. Manual wash – initial cleaning by personnel using immersion in a
cleaning solution
ii. Mechanical wash – initial cleaning by machine using some version
of washer – washer, washer disinfector, washer sterilizer
c. Lubrication – any instrument with moving parts must be lubricated following
cleaning, but not with mineral oil, silicone or machine oil, which leaves
residues that resist sterilization. To “milk” an instrument immerse in an
approved lubricant for 30 – 45 seconds, then dip and drip dry in a draining
tray. Rinse off excess solution.
2. Preparation, assembly and packaging phase: This is a Level 3 process used to assemble
instruments and supplies into penetrable packaging prior to terminal sterilization or disinfection.
1. Inspection of instruments
a. Damage
b. Stiffness
c. Not too tight or too loose, proper alignment
d. Properly sharp or dull, depending on design
2. Assembly – Distribution of instruments into instrument sets or procedure trays for
packaging and placement in sterilizer racks
3. Packaging – Selection of appropriate container
a. Rigid containers – metal/plastic hard case surrounding an internal, removable
wire basket
b. Wrapped instrument trays – Open, perforated trays with towels or foam in
the bottom to protect/absorb
c. Pre-packaged instrument sets – Double wrapped package, used for
specialized instruments or instruments that require disassembly – all parts
3. Terminal phase – Final cleaning phase used for all critical items
a. Disinfection – Level 2 process used for semi-critical items that do not have a
direct impact on patient safety
b. Sterilization – Level 1 process used for critical items that are introduced
directly into the blood stream or directly contact internal areas of the body
c. Aeration – Some methods of sterilization require a period to elapse between
end of the sterilization cycle and actual usage that involves air-drying tools
4. Storage phase – Controlled environment with limited access where surgical supplies are kept;
acceptable shelf-life in this environment depends on the procedure
HANDLING CONTAMINATED INSTRUMENTS DURING AND AFTER A SURGICAL
PROCEDURE:
1. Intra-operative or concurrent decontamination
a. Follow standard precautions when handling contaminated instruments
b. Keep all instruments used during surgical procedure free of gross soil by
wiping with a moistened sponge
2. Postoperative decontamination pre-rinse
a. Follow the four steps of instrument decontamination: pre-rinsing, washing,
rinsing and sterilizing according to the manufacturer’s recommendation
b. Disassemble instruments with removable parts to expose all surfaces for
cleaning
c. Open all hinged instruments to expose box locks and serrations
d. Begin initial instrument decontamination immediately after completion of
surgical procedures
e. Open and disassemble all ratcheted instruments before leaving the operating
room, then place in a basin of sterile water and enzymatic detergent
f. Flatten or straighten malleable instruments such as retractors and probes
g. Flush cold distilled water through hollow instruments to prevent drying of
organic debris
h. Place reusable sharps, such as skin hooks, in a separate container to prevent
injury to instrument room personnel.
i. Transport all instruments to the processing room for decontamination.
3. Decontamination Washing
a. Use automated cleaning for initial decontamination
b. Wear protective attire if manual cleaning
c. Use distilled water for cleaning.
d. Remove excessive bioburden from instruments by placing in washer
sterilizer or manually hand washing each item
e. Place instruments with crevices, serrations, box locks and ratchets in
ultrasonic cleaner after completion of washer-sterilizer cycle
f. Use an enzymatic soak solution on delicate items
g. Do not soak instruments for prolonged time
h. Use detergent with a neutral pH, never > 8.
i. Do not use abrasive agents such as wire brushes and steel wool.
4. Decontamination rinsing