Aseptic Technique & The Sterile Field
Practice for Perioperative Nurses:
As of press time in March, AORN is reviewing and updating its “Recommended Practices for Maintaining a Sterile Field.” Go to www.aorn.org for more details.
Proper aseptic technique is one of the most fundamental and essential principles of infection control in the clinical and surgical setting. The word “aseptic” is defined as “without microorganisms,” and aseptic technique refers to specific practices which reduce the risk of post-surgical infections in patients by decreasing the likelihood that infectious agents will invade the body during clinical procedures. These practices also are designed to help the surgical team avoid being exposed to blood, body fluids, tissue and other potentially infectious material (OPIM) during surgical procedures.
According to the organization EngenderHealth, aseptic techniques are those which: remove or kill microorganisms from hands and objects; employ sterile instruments and other items; reduce patients’ risk of exposure to microorganisms that cannot be removed.
The usually harmless microorganisms found on the skin of a healthcare worker (HCW) may cause infection when introduced into an area of the patient’s body where they are not normally found, such as into a client’s internal organs during surgery. These normal flora can also cause infection in an immuno-compromised patient who is especially susceptible to infection. Patients are also at risk of acquiring infections when bacteria from the patient’s own skin infect a wound, when tissue has been damaged due to rough or excessive manipulation during surgery, or when excessive bleeding makes the tissue susceptible to invasion by microorganisms. According to EngenderHealth, aseptic technique prepares patients for surgery, safeguards against excessive manipulation, and protects clients from microorganisms in the environment and on the HCW’s skin, clothes, and hair.
Aseptic technique also encompasses practices performed immediately before and during a surgical procedure to reduce post-operative infection. These include:
- Surgical scrub
- Using surgical barriers, including sterile surgical drapes and proper personal protective equipment, including head coverings, surgical masks and gowns, gloves, and shoe coverings
- Patient surgical prep
- Maintaining a sterile field
- Using safe operative techniques
- Maintaining a safe environment in the operating room
Proper preparation of the patient using an antimicrobial product prior to surgery is essential in reducing the number of microorganisms present on the patient’s skin. The patient’s surgical site should be thoroughly cleaned, and then an antiseptic applied to the skin. The HCW should gently scrub the skin in a circular motion, beginning in the center of the site and moving outward and using sterile sponges held by a sponge forceps. Shaving is no longer recommended because it causes small nicks and breaks in the skin where bacteria can grow and multiply; hair around the site may be clipped short if it might interfere with the procedure. Studies have demonstrated that patients who had not been shaved had significantly fewer post-operative infections than patients who had been shaved.
Creating and maintaining a sterile field is an essential component of aseptic technique. A sterile field is an area created by placing sterile surgical drapes around the patient’s surgical site and on the stand that will hold sterile instruments and other items needed during surgery. When a HCW has donned proper sterile surgical attire, the HCW’s sterile area is the only area that should come in contact with the sterile field. Only sterile objects and personnel may be allowed within the sterile field. When a sterile field is created around a procedure site, items below the level of the draped client are outside the field and are not sterile. Experts say that a properly gowned and gloved HCW’s sterile area extends from the chest to the level of the sterile field; sleeves are sterile from 5cm above the elbow to the cuff.
It is critical for HCWs to remember that only sterile items are free of potential infectious agents, and that once a sterile object comes in contact with a non-sterile object, surface, or person, or with dust or other airborne particles, the object is no longer sterile. To maintain the sterile field, only sterile items should be placed within the sterile field.
The integrity of sterile packages should be preserved while being opened, dispensed, or transferred. Remember that objects located below the level of the draped patient are unsterile; HCWs should not reach across unsterile areas or to touch unsterile items prior to or during the surgical procedures, and unsterile personnel should not reach across the sterile field or touch sterile items. HCWs should recognize that a sterile or high-level disinfected (HLD) barrier that has been penetrated (wet, cut, or torn) is considered to be contaminated; and finally, HCWs should be cognizant of how they move within or around the sterile field in a way that maintains sterility or HLD status.
The sterile field may also be protected by creating a safe, clean environment within the operating room. Limiting the amount of foot traffic and activities in this area may help to reduce the number of bacteria that get kicked up in the atmosphere. To maintain a safer environment, the number of HCWs entering and exiting the OR should be limited; all personnel who enter the room should wear proper PPE; proper air handling and circulation should be established; and before the patient is brought into the OR, all surfaces that may have been contaminated during the last procedure should be cleaned and disinfected according to hospital policies and procedures.
There are a number of related actions that support aseptic technique. The first is handwashing. For more than 100 years, research has shown that handwashing is the most important way to reduce the spread of infections in healthcare settings, although HCWs wash their hands only about half as often as they should. After all, hands are the most common vehicle for transmitting infections, so it is critical that HCWs understand the importance of proper handwashing practices. In brief, HCWs should wash their hands whenever there is a chance that they may have become contaminated; they should be washed before beginning a shift, immediately before and after providing patient care; before donning gloves for a clinical procedure; after touching any instrument or object that might be contaminated with blood or other body fluids; after touching mucous membranes; after handling blood, urine, or other specimens; after removing any kind of gloves; after using the restroom; and before leaving work at the end of a shift. Hands are washed to remove visible soil and invisible infectious material. They should be mechanically agitated under running water and with an antimicrobial product for approximately 15 to 30 seconds. If soap and water are not accessible, and if the hands are not visiblysoiled, the HCW may use an alcohol handrub until he or she can wash his or her hands at a sink. Alcohol handrubs should be rubbed into the hands and fingernail areas and allowed to dry before resuming any activity.
Proper gloving technique also facilitates the aseptic process. Gloves provide a barrier against potentially infectious microorganisms that can be found in blood, other body fluids, and waste. HCWs should wear the proper type of gloves whenever they might come into contact with blood and other body fluids and whenever they perform a clinical procedure that might put the patient and the HCW at risk of infection. To avoid exposing one patient to potentially infectious microorganisms acquired from another patient, HCWs must use fresh gloves every time they encounter a different patient, making sure to wash their hands before and after they don gloves.
Wearing proper PPE is a third way to support aseptic technique. During surgical procedures, both patients and HCWs are especially at risk of exposure to potentially infectious microorganisms. Along with the other elements of aseptic technique, proper surgical attire helps reduce the risk of post-procedure infections by decreasing the likelihood that microorganisms will enter areas of the patient’s body during procedures. Some elements of surgical attire are also designed to reduce HCWs’ risk of exposure to potentially infectious blood and tissue during surgical procedures. Surgical attire includes caps, gloves, masks, gowns, protective eyewear, fluid-proof aprons, and footwear.
A fourth component of aseptic technique is surgical prep. The warm, moist conditions inside surgical gloves provide an ideal environment for the rapid growth of microorganisms, so scrubbing with antiseptics before beginning surgical procedures will help prevent this rapid growth of microorganisms for a period of time and will reduce the risk of infections to the patient if the gloves develop holes, tears, or nicks during surgery.
Antimicrobial agents are used in the surgical scrub because they inhibit the growth and development of microorganisms and are safe for use on the skin. A 3-to5-minute surgical scrub with an antiseptic (such as chlorhexidine or an iodophor) and running water is recommended before a surgical procedure.
EngenderHealth suggests that infection control practitioners (ICPs) can make significant strides in educating HCWs about infection-prevention practices at their healthcare institutions. It recommends that ICPs:
- Investigate whether proper aseptic technique is being followed in the OR, and whether antiseptic products such as surgical scrubs and surface disinfectants are being used properly.
- Hold regular in-service training for HCWs and provide updates on clinical/surgical infection control techniques. Information about proper infection control and prevention practices, including all aspects of aseptic technique, should be a part of this in-service training. HCWs are often confused about the differences between antiseptics and disinfectants and often use these solutions inappropriately; ICPs should ensure that proper use of antiseptic solutions is part of any in-service training.
- ICPs should continue to serve as exemplary role models for OR personnel and other HCWs. Model aseptic behavior during the course of the day and encourage colleagues to do the same. If ICPs identify practices that endanger patients or staff, or may promote the opportunity for infections, it is their obligation to address the improper behavior.