Principles of Surgical Asepsis

PRINCIPLES OF SURGICAL ASEPSIS

Surgical asepsis prevents the contamination of surgical wounds. The patient’s natural skin flora or a previously existing infection may cause postoperative wound infection. Rigorous adherence to the principles of surgical asepsis by OR personnel is the founda-tion of preventing surgical site infections.

All surgical supplies, any instruments, needles, sutures, dress-ings, gloves, covers, and solutions that may come in contact with the surgical wound and exposed tissues, must be sterilized before use (Meeker & Rothrock, 1999; Townsend, 2002). Traditionally, the surgeon, surgical assistants, and nurses prepared themselves by scrubbing their hands and arms with antiseptic soap and water, but this traditional practice is being challenged by research investigat-ing the optimal length of time to scrub and the best preparation to use (Larsen et al., 2001). (See Nursing Research Profile 19-1.)

Surgical team members wear long-sleeved sterile gowns and gloves. Head and hair are covered with a cap, and a mask is worn over the nose and mouth to minimize the possibility that bacte-ria from the upper respiratory tract will enter the wound. During surgery, the personnel who have scrubbed, gloved, and gowned touch only sterilized objects. Nonscrubbed personnel refrain from touching or contaminating anything sterile.

An area of the patient’s skin considerably larger than that re-quiring exposure during the surgery is meticulously cleansed, and an antimicrobial agent is applied. If hair needs to be removed, it is done immediately prior to the procedure to minimize the risk of wound infection (Townsend, 2002). The remainder of the pa-tient’s body is covered with sterile drapes.

Environmental Controls

In addition to the protocols described previously, surgical asepsis requires meticulous cleaning and maintenance of the OR envi-ronment. Floors and horizontal surfaces are cleaned frequently with detergent, soap, and water, or a detergent germicide. Steril-izing equipment is inspected regularly to ensure optimal opera-tion and performance.

All equipment that comes into direct contact with the patient must be sterile (Townsend, 2002). Sterilized linens, drapes, and solutions are used. Instruments are cleaned and sterilized in a unit near the operating room. Individually wrapped sterile items are used when additional individual items are needed.

Airborne bacteria are a concern. To decrease the amount of bacteria in the air, standard OR ventilation provides 15 air ex-changes per hour (Meeker & Rothrock, 1999). Staff members shed skin scales, resulting in about 1,000 bacteria-carrying parti-cles (or colony-forming units [CFUs]) per cubic foot per minute. With the standard air exchanges, air counts of bacteria are re-duced to 50 to 150 CFUs per cubic foot per minute. The num-ber of personnel and unnecessary physical movements may be restricted to minimize bacteria in the air and achieve an OR in-fection rate no greater than 3% to 5% in clean, infection-prone surgery.

Some ORs have laminar airflow units. These units provide 400 to 500 air exchanges per hour. When used appropriately, laminar airflow units result in less than 10 CFUs per cubic foot per minute during surgery. The goal for a laminar flow-equipped OR is an in-fection rate under 1%. An OR equipped with this unit is frequently used for total joint replacement or organ transplant surgery.

Despite all these precautions, wound contamination may occur during surgery but may only become apparent days or weeks later in the form of an incisional infection or abscess. Constant surveil-lance and conscientious technique in carrying out aseptic practices is necessary to reduce the risk for contamination and infection.

Basic Guidelines for Maintaining Surgical Asepsis

All practitioners involved in the intraoperative phase have a re-sponsibility to provide and maintain a safe environment. Adher-ence to aseptic practice is part of this responsibility. The eight basic principles of aseptic technique follow:

·        All materials in contact with the surgical wound and used within the sterile field must be sterile. Sterile surfaces or ar-ticles may touch other sterile surfaces or articles and remain sterile; contact with unsterile objects at any point renders a sterile area contaminated.

·        Gowns of the surgical team are considered sterile in front from the chest to the level of the sterile field. The sleeves are also considered sterile from 2 inches above the elbow to the stockinette cuff.

·         Sterile drapes are used to create a sterile field. Only the top surface of a draped table is considered sterile. During draping of a table or patient, the sterile drape is held well above the surface to be covered and is positioned from front to back.

·        Items should be dispensed to a sterile field by methods that preserve the sterility of the items and the integrity of the sterile field. After a sterile package is opened, the edges are considered unsterile. Sterile supplies, including solutions, are delivered to a sterile field or handed to a scrubbed person in such a way that the sterility of the object or fluid remains intact.

·         The movements of the surgical team are from sterile to ster-ile areas and from unsterile to unsterile areas. Scrubbed per-sons and sterile items contact only sterile areas; circulating nurses and unsterile items contact only unsterile areas.

·        Movement around a sterile field must not cause contami-nation of the field. Sterile areas must be kept in view during movement around the area. At least a 1-foot distance from the sterile field must be maintained to prevent inadvertent contamination.

·         Whenever a sterile barrier is breached, the area must be con-sidered contaminated. A tear or puncture of the drape per-mitting access to an unsterile surface underneath renders the area unsterile. Such a drape must be replaced.

·        Every sterile field should be constantly monitored and maintained. Items of doubtful sterility are considered un-sterile. Sterile fields should be prepared as close as possible to the time of use.