Infection Control Today - 06/2001: Instrumental Knowledge

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The Care and Handling of Instruments in the Sterile Field

By Christine E. Wilson

The maintaining of a sterile field in the OR is of utmost importance. Patients are always at risk for secondary infections, and any procedures and preparation that can be done to minimize this should be followed scrupulously.

The Parameters of the Sterile Field

The confines of the sterile field vary, but normally include the back table, mayo stand, draped patient, and a portion of the front of the gowns of the surgeons and scrub techs. More specifically, the top of the back table, the mayo stand, and generally 12 inches beyond the surface of these tabletops is restricted as the sterile area. When opening containers and preparing supplies and instruments to be used for the surgical procedure, healthcare workers (HCWs) must be careful not to contaminate them. Thus, these items must be flipped from the packages onto the back table when the HCW is standing at least a foot away.

Surgeons and scrub technicians operate within the confines of the sterile area, while the circulating nurse remains outside of it. The gowns of those within the sterile area are generally considered sterile on the front side only--from the waist, or the level of the tabletop, to the shoulders. Their hands and arms are also considered sterile, up to two inches above the elbow, because this is the area covered during the pre-op sterile scrub. However, their shoulders, necks, faces, and backs are considered unsterile. Because the back of each individual is not sterile, they must be careful when they pass each other inside the sterile area. For example, they cannot pass one another front to back, because then they have risked contamination. Thus, they must pass front-to-front or back-to-back only.

The incision site of the patient is covered first by sterile towels and then by a large drape with an opening that exposes the incision site. The patient, the towels, the drape, and the table top all lie within the sterile field.

A surgical consciousness has developed over the years to the point where some surgeons have become extremely meticulous in maintaining the sterile area. For example, Lynette King, RN and manager of Perioperative Services at the Mayo Clinic in Phoenix, Ariz relates how one doctor she worked with ordered that the entire OR was contaminated when the corner of one drape touched the floor. Thus, they had to tear down everything and recreate a new sterile field in order to avoid any chance of bacteria entering the original sterile field.

Early Pioneers

Louis Pasteur is known as the father of bacteriology. Through his research in fermentation and putrefaction in the mid-nineteenth century, he realized that spontaneous generation was not the end result, but merely a step in the process. He found that if all living germs were destroyed and no new ones were allowed to enter, then fermentation or putrefaction would not occur. He went on to discover the causes of diseases such as anthrax, fowl cholera, and rabies, and proceeded to create vaccinations against these diseases. He also continued his studies in bacteriology with children suffering from fever in hospitals and discovered the presence of staphylococci. His research, which won him many honors and much recognition, has influenced the study of sterilization throughout history.

Joseph Lister was a British surgeon who discovered antiseptics in 1865. This finding greatly reduced the number of deaths that occurred as a result of infections created in the operating room. The principle of antisepsis that he developed grew out of Pasteur's theory that bacteria caused infection. Before surgery, Lister sprayed the operating rooms with carbolic acid, because he thought that the infections were caused by dust particles in the air. He then started applying carbolic acid to any of the materials he used for surgery, including instruments and bandages. By 1869, he had already reduced the number of deaths from surgery by 12%. Thus, his methods eventually became widely accepted and he is credited with the beginnings of sterilization in the operating room.

Practical applications

The members of the surgical team have to be very careful about not breaching the sterile field. If, for example, an instrument falls on the floor, it immediately becomes unsterile, and thus, they cannot touch it. It is the circulating nurse, who operates outside the sterile field, who must pick it up. The HCW picks it up, rinses it off, and has one of two options to follow. According to Sheila Griffin, RN, a traveling OR circulating nurse with Medical Express, if the instrument is not critical to the surgical procedure, it is then put on the dirty case cart, so that it can be collected after the procedure is completed. If the instrument is critical to the procedure, however, and there is no other instrument of the same kind and size available, then the circulating nurse places it in an autoclave for three minutes to resterilize it, and then returns it to the OR. All instruments--whether sterile or unsterile--must be accounted for after the procedure.

According to Pat Menges, RN and director of Perioperative Services at Good Samaritan Regional Medical Center in Phoenix, Ariz the rules of sterilization are absolute and the entire team is responsible for maintaining these rules. It is the job of the circulating nurse, however, to watch over everyone and everything, and to make sure that the sterile field is not breached. If someone from radiology enters the room, for example, the circulating nurse must be sure that this person remains outside the sterile field and doesn't touch anything. Likewise, if the sleeve of the surgeon's gown inadvertently touches the back of another team member, the circulating nurse must warn the surgeon that this has happened. The general rule is when in doubt, throw it out, or change it (referring to a gown, glove, instrument, etc.).

The operating room of the near future

Maintaining the sterile field and ease of operation in the OR of the future will become even more effortless than it is today. A number of hospitals on the cutting edge of technology, such as the University of Pittsburgh Medical Center, are now allowing the use of robotic surgical systems to be tested and used. Surgeons are experimenting with the use of robots which not only enhance the precision and control of the procedure, but also aid the surgeons by being an extra "hand." In addition, they are voice activated. Thus, the operating team is able to access information from outside the sterile field or to make commands by simply speaking aloud. For example, altering the light source, moving the OR table, adjusting the cameras and other monitors, etc., are easily done with the use of the robotic system, whereas in traditional operating rooms, these tasks all had to be done manually by personnel either inside or outside of the sterile field. This eliminates the need for some of the nonsterile assistants or the relaying of information between the surgeon and the staff outside the sterile environment.

Once these robotic devices become mainstream, the lines between the sterile and nonsterile fields may blur somewhat, but they will not compromise the safety of the patients. There will still be a circulating nurse on hand to make sure that there will be no breach of security. Thus, the patients can be assured that the sterile field will remain intact.

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