FOR ASEPTIC SURGERY (NON-RODENTS)
(Revised April 2005)
Animal surgical procedures must be conducted in accordance with
the requirements of:
- The Guide for the Care and Use of Laboratory
Animals [The Guide] (Institute of Laboratory Animal Resources,
National Research Council, 1996)
- Animal Welfare Regulations (AWR, CFR 1985),
- Public Health Service Policy on Humane Care
and Use of Laboratory Animals (PHS Policy, 1996).
The "Guide" classifies surgical procedures under
the category of Veterinary Medical Care. It specifically
states that: "appropriate attention to pre-surgical planning,
personnel training, aseptic and surgical technique,
animal well being, and animal physiologic status during all phases
of a protocol will enhance the outcome of surgery.
It further states that:
"Aseptic technique is used to
reduce microbial contamination to the lowest possible practical
level. No procedure, piece of equipment, or germicide alone can
achieve that objective. Aseptic technique requires the input and
cooperation of everyone who enters the opemrating suite. The contribution
and importance of each practice varies with the procedure.
Aseptic technique includes:
- Preparation of the patient; such as hair
removal and disinfection of the operating sites.
- Preparation of the surgeon such as the
provision of decontaminated surgical attire, surgical scrub,
and sterile surgical gloves.
- Sterilization of instruments,
supplies, and implanted materials; and
- The use of operative techniques to reduce
the likelihood of infection"
The purpose of the following guidelines is to
assist the investigators in complying with these requirements.
In general, unless an exception is specifically justified
as an essential component of the research protocol and approved
by the IACUC, the investigators should follow these guidelines.
A) Principles of Surgical Techniques
- All items used in any surgical procedure
must be sterilized.
- Persons who have scrubbed should touch only
sterile items. Persons who have not scrubbed should touch only
- If the sterility of any items is in doubt
it should be considered non-sterile.
- If a non-scrubbed person touches a
sterile table re-drape the table.
- If a scrubbed person touches
a non-sterile table that person should re-gown or cover
- Any sterile table or sterile item left
unguarded or uncovered should be considered non-sterile.
- If the autoclave tape is only partially
changed in color the item should be considered non-sterile.
- When preparing for surgery, personnel should:
- First put on a cap and then a mask.
- Scrub from fingers to 2-3 inches above
- Open gown and glove packs and put on
gown and gloves.
- Persons who have not scrubbed should avoid
reaching over sterile fields and those who have scrubbed should
avoid leaning over non-sterile areas.
Tables are considered sterile only at tabletop
level or above.
- The scrubbed person should set basins
to be filled at the end of the table.
- The circulator should stand at a distance
from the sterile field when adjusting the light.
- The surgeon should turn away from the field
to have his/her brow mopped.
- The scrubbed person should drape the sterile
tables nearest him/her first.
Gowns are considered sterile only from waist
to shoulder level and in front or on the sleeves.
- Linen or sutures falling below table level
are considered non-sterile and discarded.
- When draping the table the part of the
sheet that drops below the table surface should not be brought
up to table level again.
While scrubbing, keep hands in sight above
waist level, and away from the face.
When standing on stools, the area of the
gown below the waist must not brush against the sterile table.
Arms should never be folded; perspiration
in the axillary region may lead to contamination.
Articles dropped below waist level must be
Scrubbed persons should keep well within
the sterile area. A wide margin of safety should be allowed
when passing non-sterile areas.
Persons who have not scrubbed should avoid
- Scrubbed persons should:
- Keep a safe distance from the operating
table when draping the patient.
- Pass each other back to back.
- Turn their back to a non-sterile area
- Face a sterile area when passing it.
- Ask a non-scrubbed person to step aside
rather than trying to crowd past him/her.
- Stay near and facing the sterile tables
if waiting for the animal to be prepped.
Moisture allows bacteria to the sterile area
- If a person who has not scrubbed must
pass a sterile area he/she should face the area when passing
to make certain it has not been touched.
Sterile packages should be laid only on dry
When bacteria cannot be eliminated from a
field, they should be kept to an irreducible minimum. Patient
skin cannot be sterilized and is a source of potential contamination
from both the patient and members of the operating team. To
minimize contamination potential:
- If a sterile package becomes damp or wet,
it should be re-sterilized or discarded.
- If a solution soaks through a sterile drape
to a non-sterile area, the wet area should be covered with
another sterile drape.
- The patient is shaved and scrubbed in
the prep area and is given a final sterile scrub in the operating
- When draping, all skin should be covered
except the site of incision.
- All surgeons and assistants must scrub
their hand and arms.
- All surgeons and assistants must gown and
glove without touching the outside of the gown and gloves.
- Hand towels should not touch scrub suits
while drying hands after scrubbing.
- In some cases the knife blade used for
the skin incision should be considered contaminated and should
not be used deeper than the skin.
- If a glove is contaminated during the procedure
it must be changed at once. If an instrument punctures the
glove, the instrument must also be handed off.
All drugs, medical supplies, and sterilized items used during
surgery must be current. No outdated material can be used.
B) Cleaning Instruments
- Prior to sterilization, all instruments
must be cleaned to remove debris, blood, oil, etc. The two common
methods of cleaning include:
- Rinse the instruments in tap water as soon
as surgery is over. This prevents blood from drying in serration
and box locks.
- Open all box locks and disassemble instruments.
- Scrub each instrument with a soft brush in
warm water with an instrument detergent with a pH near 7.0-8.5.
Wear gloves and be mindful of sharp edges on instruments.
- Inspect each instrument for proper function
and cleanliness; particularly box locks, grooved ends, and other
areas not readily exposed.
- Rinse the instruments with water (distilled
if available) to ensure removal of detergent. Distilled water
is used to prevent mineral deposits on the instrument surfaces.
If distilled water is not available and tap water is used, hand-dry
the instruments to remove mineral deposits from the water.
- Instrument "milk" can be used to
Ultrasonic cleaning is a more effective cleaning method than manual
cleaning. It can penetrate areas that a hand brush cannot reach.
Cleaning is accomplished by the use of high frequency sound waves
converted in the solution into mechanical vibrations, which pull
soil out of instruments. The ultrasonic method typically removes
about 90% of soil. However, it is important to recognize that it
does not sterilize, or eliminate the need for initial removal of
obvious blood and soil. Ultrasonic cleaning is most effective when
it follows a preliminary manual cleaning to remove accessible debris
from the instruments. When using an ultrasonic cleaner, always:
- Follow manufacturer's instructions carefully.
- Use the detergent solution recommended by
- Strictly adhere to the cleaning times and
temperatures recommended by the manufacturer.
- Use distilled water/or de-mineralized water.
- Rinse instruments with box locks open and
- Do not overload cleaner.
- Inspect instruments carefully on a regular
basis; ultrasonic cleaning can accelerate flaking of chrome
plated instruments and loosen small screws in instruments.
C) Sterilizing Instruments
As described above, the use
of sterilized instruments is a critical requirement of sterile
survival surgery techniques. All instruments
used in these surgeries must be sterile. Specific sterilization
methods should be selected on the basis of physical characteristics
to be sterilized. Sterilization indicators should be used
to identify materials that have undergone proper sterilization.
The use of liquid chemical sterilizing agents must be conducted in approved
facilities with adequate ventilation systems and
should be used with adequate contact times. Instruments should
be rinsed with sterile
water or saline before use. Alcohol is not a sterilizing
- All articles to be sterilized must be clean.
- All articles to be
sterilized should be packaged in materials (such as paper,
muslin, cloth, peel packs, etc.) that protect
them from contamination. The material must be porous
enough to allow the penetration
of the sterilizing agent (e.g. steam).
- Date (must include
the sterilization date) and label the sterilized items.
If multiple sterilizers are used
by a laboratory group, the specific
sterilizer should also be indicated on the package.
of the sterilizing process should be measured at
regular intervals with a biological
indicator (refer to UCSF Biological Safety Manual
- Store sterilized items in a clean, dust-proof
and low-humidity area. Closed storage cabinets prevent
effectively. Storage under sinks or in places
likely to result in wetting
is to be avoided.
- Any sterilized package that is
dropped or torn or has come in contact with moisture is
considered contaminated and must be cleaned, repackaged and
re-sterilized. All packages containing
sterile items should
be inspected before use to verify package integrity
- If the package has remained intact
and dry, items may be considered sterile until the time