A sterile field is a designated area prepared to be free of all living microorganisms, including bacterial spores, ensuring a protective environment during invasive medical procedures. This controlled zone is established using specialized sterile drapes, instruments, supplies, and equipment. Maintaining this microbe-free state, known as surgical asepsis, protects the patient from infection during surgery or procedures where the skin barrier is compromised. Eliminating pathogens from the environment reduces the risk of a surgical site infection. This principle of infection control is necessary whenever the patient’s internal tissues are exposed.
Defining a Breach of Sterility
A breach of sterility occurs when any non-sterile item or person contacts the prepared field. One common rule involves moisture, where a sterile item becomes contaminated if its protective packaging or drape becomes wet, a phenomenon called strike-through. Since microorganisms travel through moisture from an unsterile surface to a sterile one, dampness renders the barrier ineffective and the equipment unusable.
The physical boundaries of the sterile field are strictly defined, and crossing them constitutes a breach. The outer perimeter of any sterile drape or wrapper is non-sterile, typically extending about one inch inward from the edge. Items that fall below the level of the procedural table or the waist of the scrubbed personnel are considered contaminated because they cannot be kept within the line of sight. Sterile items exposed to the air for a prolonged duration also risk contamination from airborne microorganisms.
Contamination also frequently involves unscrubbed personnel violating the designated safe zone. Non-sterile team members should maintain a minimum distance of 12 inches from the sterile field to prevent accidental contact. If a non-sterile person reaches over the field, or if a scrubbed person turns their back to the field, sterility is immediately lost. Recognizing these conditions is the first step in initiating the corrective protocol.
Immediate Response Protocol for Personnel
Upon recognizing an event that compromises the sterile field, the immediate action is to stop the procedure or task. This halt prevents the use of contaminated equipment and protects the patient from potential infection. The next action is clear communication to the entire procedural team regarding the nature of the breach. This notification ensures all personnel are aware of the contamination and can adjust their actions.
The team member who identifies the breach must speak up, as patient advocacy is the highest priority, even if it delays the procedure. After communication, the specific contaminated item or area must be isolated and removed from the field. This step must be performed without attempting to fix the item or allowing it to remain near the remaining sterile supplies. Any team member who touched the compromised area must change their sterile gloves immediately.
Following the isolation of the contaminated item, the surgical team, particularly the surgeon, must discuss the implications for the patient. This discussion may involve considering the wound classification and whether the patient requires preventative measures, such as supplemental antibiotics. Documentation of the event must also be initiated, often through an incident report. The report records the breach and corrective actions taken, allowing for subsequent review to determine the root cause and prevent recurrence.
Steps for Replacing Contaminated Materials
Restoring the sterile environment requires a systematic, sequential process that begins with the physical removal of all compromised items. The contaminated supplies must be carefully retrieved from the field and placed into a designated receptacle for disposal or reprocessing. Personnel must ensure that the non-sterile exterior of the item is the only part touched during removal. Any instruments that were contaminated must be removed for reprocessing, which includes an initial point-of-use cleaning to remove organic material like blood and tissue, preventing the formation of protective microbial biofilms.
For personnel whose gowns or gloves were contaminated, a complete change of attire may be necessary to re-establish their sterile status. A sterile gown is considered sterile only on the front, extending from the chest level down to the sterile field, and on the sleeves from two inches above the elbow to the cuff. If a breach occurred in one of these zones, the personnel must step away from the field and undergo a full re-gowning and re-gloving procedure. This procedure often utilizes the closed-gloving technique to maintain a barrier between the hands and the outside of the glove.
The final step involves completely breaking down the remainder of the compromised field and meticulously recreating a new one using all new sterile supplies. When opening new materials, the unscrubbed person must open the flap of the wrapper farthest from them first, pulling the sides and the near flap last. This specific sequence prevents their non-sterile arms from reaching over the sterile contents. New sterile drapes must be handled carefully, held above waist level, and placed without rapid motions like flipping or fanning, as this can create air currents that deposit contaminants.