Infection Control Today - 08/2003: Guidelines for Maintaining the SterileField

Guidelines for Maintaining the Sterile Field

By John Roark

Event Related Sterility (ERS) has become awell-accepted standard in the processing of sterile healthcare devices andsupplies since the early 1990s. The idea behind ERS is that if a sterile item(packaged according to acceptable protocols) and its packaging have not beencompromised, the item is considered to be sterile and safe for use. With ERS,sterile packaged items are assumed to be sterile as long as the package isintact; length of time since sterilization is irrelevant.

The techniques used during processing bymanufacturers produce a totally sealed package made of impervious materials.Typical ERS package labels read, Contents sterile unless package is open ordamaged. Inspect before use.

In any situation, each package of sterile itemsmust be carefully inspected by the end user for any break in integrity regardless of expiration date or event-related processes. Breaks in integritycan include evidence of holes and tears, watermarks that may indicate that theitem was wet after sterilization, and defects in peel-pouch seals. Inspectionfor these breaks is a priority when handling any packaged sterile item ordevice.1

Establishing a Sterile Field

Rigorous adherence to the principles of asepsisby all scrubbed personnel is the foundation of surgical site infectionprevention. Others who work in close proximity to the sterile field must alsoabide by these principles.

Nonsterile equipment or furniture, such as theMayo stand, should be covered appropriately with sterile barrier materials if itis to be used during the procedure. Only sterile items should touch or extendover sterile surfaces.

Opening Packs

Sterile drapes establish an aseptic barrier thatminimizes the passage of microorganisms between non-sterile and sterile areas.

The drape pack should be placed on a clean, drysurface and unfolded by touching only the outside of the wrapper. The inside ofthe outer wrapper becomes the table drape and the base of the sterile field.Care must be taken so that the inside or sterile portion of the wrapper does nottouch any part of the non-sterile surface.

Inspection for tears, holes or areas ofstrikethrough should be performed immediately, before additional items areplaced on the sterile field. When opened, the edges of the drape are considerednon-sterile below the level of the table or other flat surface.

Opening Sterile Items

Before presentation to the sterile field, allsterile items should be inspected for proper packaging, processing, seal,package integrity and the inclusion of a sterilization indicator and expirationdate, if indicated.

  • Surgical supplies should be opened only when there is reasonable certainty that they will be used during the procedure.

  • Items that are introduced into the sterile field must be sterile and remain sterile until they are used. Secure packaging, sterilization, delivery to the field and handling during use should provide that assurance.

  • Items introduced onto a sterile field should be opened, dispensed and transferred by methods that maintain sterility and integrity.

  • Some sterile items (e.g., suture packages) are designed to be flipped onto the sterile field. The inner edge of the seal of the peel package is considered the sterile boundary. With instruction and practice, items can be safely flipped onto the sterile field without contaminating the field by reaching over it.

Sterile Storage

The Association of periOperative RegisteredNurses (AORN) recommends that access to the sterile storage area should belimited and separated from high-traffic areas. Sterile supplies should be storedseparately from clean supplies. Sterile materials may be stored in either openor closed shelving that is at least eight to 10 inches from the floor, at least18 inches from the ceiling, and at least two inches from outside walls.

When open shelving is used, a solid shelf or totebox should be used on the bottom shelf to create a barrier between the floor andthe bottom shelf. The temperature of the area should be controlled between 65 to72 degrees F (18 to 22 degrees C) with humidity maintained between 35 and 50percent.

If clean and sterile supplies must be storedwithin the same cupboard or shelving unit, the sterile items should be stored onthe upper shelves above the clean items. Storing sterile items above clean itemsreduces the risk of lint, dust, and other debris falling from clean items ontothe sterile items. Neither clean nor sterile supplies should be stored next toor under sinks, exposed water or sewer pipes, or in locations where they canbecome wet.2

Dropped Items

If a sterile package is dropped, the item may beconsidered safe for immediate use only if it is enclosed in impervious packagingthat was not punctured or torn on impact. If the wrapper is impervious and thearea of contact is dry, the item may be transferred to the sterile field.Dropped items wrapped in reusable woven fabric materials should not betransferred to the sterile field because these materials allow air to implodeinto the package.

A dropped package should not be put back intosterile storage.

Traffic Patterns

Surgical suites and traffic patterns are designedto facilitate movement of patients and personnel into, through and out ofdefined areas within the surgical suite. Increasing environmental controls andthe use of additional surgical attire as the progression is made fromunrestricted to restricted areas decreases the potential forcross-contamination. Signs should be posted that clearly indicate theappropriate environmental controls and surgical attire required. All persons(staff, patients and visitors) should follow the delineated patterns inappropriate attire.

There are at least 15 air changes per hour,which is code for a garden-variety OR, says Barbara Gruendemann, RN, MS, FAAN,CNOR, co-author of Infection Prevention in Surgical Settings.When youhave positive-pressure rooms, every time you open the doors to the OR, to someextent it will disrupt those airflow currents. Doors should be kept closed asmuch as possible during the procedure after the patient is wheeled into the roombecause we know that there are some potentially infectious agents that arepropelled through the air. The more you open and close the doors to the room,the more airborne contamination you will get. She continues, Even thoughthe degree to which airborne contaminants contribute to surgical site infectionis unknown, we do know that it has some influence. I think thats the mostcommon mistake involving traffic patterns opening and closing doors. Itshould be kept to an absolute minimum.

Researchers believe that the OR environment,including the people involved in a surgical procedure and the existing trafficpatterns, is a major source of contamination that increases both with movementand talking. AORNs Recommended Practices for Traffic Patterns in theSurgical Suite, is designed to reduce the amount of airborne contaminationduring surgery. AORN recommends that movement of staff members should be kept toa minimum while a surgical procedure is in progress. This includes minimizingthe number of people in the OR, movement, and talking during surgery andmaintaining that the OR doors be closed except during movement of staff membersor equipment. AORN reasons that:

  • Greater amounts of airborne contamination can be expected with increased movement

  • The mixing of OR air with corridor air increases the bacterial count in the room

  • Shedding increases with activity.3