j. Whenever microorganisms cannot be eliminated from a field, they should be
kept to an absolute minimum. Although absolute asepsis in an operative field cannot be
reached, every effort is made to control sources of possible contamination.
(1) Skin cannot be sterilized. Skin normally harbors staphylococcus and
other organisms; however, any agent capable of sterilizing skin will also destroy it. The
skin of the patient, as well as that of members of the "sterile" team, is therefore a
potential source of contamination in every operation. However, this does not remove
the need for strict aseptic technique. Defenses within the patient's body will usually
overcome the relatively few organisms left on the skin when the following protective
measures are carried out.
(a) The patient's skin is given a shave and scrub just prior to surgery
and is again thoroughly cleansed in the operating room just prior to the incision.
(b) As much of the operative area is cleansed as is feasible and the
surrounding skin is scrubbed.
(c) Some areas cannot be scrubbed vigorously. Mucous membranes
are gently prepped since scrubbing would damage the tissue. When the site of
operation is the mucous membrane of the nose, mouth, throat, or anus, the number of
microorganisms present is great. However, these parts of the body do not usually
become infected by organisms that normally inhabit them.
(d) When scrubbing the patient's skin, a sponge is used only once for
prepping an area. Once the sponge is removed from contact with the skin, the sponge
is discarded into a kick bucket.
(e) All of the patient's skin area except the site of incision is covered
with sterile drapes.
(f) Sterile towels or other sterile material may be used to cover the
skin after the incision is made. The reason for this additional precaution is to protect the
surgical wound from the waste products continually excreted by the skin. In addition,
airborne organisms continuously pose a threat of contaminating the incision.
(g) When the knife used for the skin incision is no longer needed, the
scrub isolates it from other items on the sterile field.
(h) The skin of operating room personnel is another source of
contamination. They follow rigid steps in scrubbing their hands and arms using brushes
and detergents and adhering to strict technique. This is done to remove the maximum
number of organisms. When drying their hands, sterile hand towels should not touch
their scrub clothes.