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sleeves. Only the front of the gown is con-
sidered sterile.
l Sterile surgical gloves are considered asep-
tic. If they are torn, punctured, or have
touched an unsterile surface or item, they
are considered contaminated.
l The safest, most practical method of
sterilization for most articles is steam
under pressure.
. Label all prepared, packaged, and steri-
lized items with an expiration date.
. Use articles packaged and sterilized in cot-
ton muslin wrappers within 28 calendar
days.
l Use articles sterilized in cotton muslin
wrappers and sealed in plastic within 180
calendar days.
l Unsterile articles must not come in contact
with sterile articles.
. Make sure the patient’s skin is as clean as
possible before a surgical procedure.
. Take every precaution to prevent con-
tamination of sterile areas or supplies by
airborne organisms.
Methods of Sterilization
Sterilization refers to the complete destruction
of all living organisms, including bacterial spores
and viruses. The word sterile means free from or
the absence of all living organisms. Any item to
be sterilized must be thoroughly cleaned
mechanically or by hand, using soap or detergent
and water. When cleaning by hand, apply fric-
tion to the item by using a brush. After cleaning,
thoroughly rinse the items with clean, running
water before sterilization.
The appropriate
sterilization method is determined according to
how the item will be used, the material of which
the item is made, and the sterilization methods
available. Physical methods of sterilization com-
prise moist heat and dry heat. Chemical methods
include gas and liquid solutions.
PHYSICAL METHODS.— Steam under
pressure (autoclave) is the most dependable and
economical method of sterilization. It is the
method of choice for metalware, glassware, most
rubber goods, and dry goods. All articles must
be correctly wrapped or packaged so that the
steam will come in contact with all surfaces of the
article. Similar items should be sterilized together,
especially those requiring the same time and
temperature exposure. Articles that will collect
water must be placed so the water will drain out
of the article during the sterilization cycle. A
sterilizer should be loaded in a manner that will
allow the free flow of steam in and around all ar-
ticles. Each item sterilized must be dated with the
expiration of sterility. Sterilization indicators must
be used in each load that is put through the
sterilization process. This verifies proper steam
and temperature penetration.
The operating instructions for a steam
sterilizer will vary according to the type and
manufacturer. There are a number of manufac-
turers, but there are only two types of steam under
pressure sterilizers. They are the downward
displacement and the prevacuum, high-tempera-
ture autoclave.
In the downward (gravity) displacement
autoclave, air in the chamber is forced downward
and out of the bottom discharge outlet as
pressurized steam enters from the top of the
chamber. The temperature in the sterilizer
gradually increases as the steam heats the chamber
and its contents. The actual timing does not begin
until the temperature is above 245°F (118°C).
The prevacuum, high-temperature autoclave
is the most modern and economical to operate and
requires the least time to sterilize a single load.
By use of a vacuum pump, air is extracted from
the chamber before admitting steam. This
prevacuum process permits instant steam penetra-
tion to all articles and through all cotton or linen
dry goods. The sterilization time is reduced to 4
minutes. The temperature in the chamber is ra-
pidly raised and held at 274°F (134°C). Timing the
cycle is done automatically.
If the temperature is increased, the steriliza-
tion time may be decreased. The following are
some practical sterilization time periods:
@ 3 minutes at 270°F (132°C)
. 8 minutes at 257°F (125°C)
Q 18 minutes at 245°F (118°C)
All operating rooms are equipped with high-
speed (flash) sterilizers. Wrapped, uncovered,
opened instruments placed in perforated trays are
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