4 Common Sterile Technique Questions Answered

Sterile technique is used every day in perioperative clinical practice but is not always clearly defined and articulated, which can lead to questions.

AORN subject matter expert Julie Cahn, DNP, RN-BC, CNOR, ACNS-BC, CNS-CP, frequently fields sterile technique questions. Here she answers four of the most common sterile technique questions nurses ask AORN and suggests the fastest ways to get answers to your pressing sterile technique questions.

1. How long can a covered sterile field sit?
   AORN does not have a recommendation on the length of time a table may be covered because the evidence is extremely limited.
   
   For example: One study by Markel et al (2018) compared covered and uncovered instrument tables and reported significantly reduced levels of bacterial contamination for covered tables at four and eight hours. At 24 hours there was no difference in contamination rates between covered and uncovered tables, Cahn explains.
   
   Recommended practice: Opening sterile supplies and instruments as close to the time of use should be the primary strategy for reducing exposure to air contamination. Covering a sterile field when there is an unanticipated delay or increased activity is a secondary strategy. “Covering of sterile fields should NOT be used as a matter of convenience, such as to set up early,” she stresses.
2. When is re-draping called for?
   Draping is performed to create a sterile field. When a drape becomes (or is suspected to be) contaminated, a new sterile drape should be placed over the contaminated drape.
   
   For example: Common practice examples of drape contamination could be related to using a c-arm in lateral position, when there is strike through, or when there is a hole or tear in the drape, Cahn notes.
   
   Recommended practice: Removing a contaminated drape may increase the risk of contamination to other parts of the sterile field or personnel and may increase lint in the air. Therefore, “unless there is a clear indication that the contaminated drape needs to be removed, it may be better to place a new sterile drape over it,” Cahn advises. She also explains that sterile towels and dressings are NOT considered drapes and should not be used to cover holes or unsterile areas of a drape.
3. Can sterile and non-sterile supplies be stored together?
   The short answer is yes. AORN is commonly asked about requirements for storing sterile and non-sterile supplies in the same location.
   
   For example: Sterile and non-sterile supplies and clean equipment may be stored in the same storage area.
   
   Recommended practice: When using the same space for sterile and nonsterile supplies and clean equipment, follow the environmental requirements for storing sterile supplies, including:

• positive-pressure relationship to the adjacent spaces,
• minimum of four total air exchanges per hour,
• minimum of two total outside air exchanges per hour,
• maximum temperature of 75 F (23.9 C),
• and maximum relative humidity of 60%.

The manufacturer’s requirements for storing sterile items should also be met, Cahn reminds. Sterile supplies should be stored above unsterile supplies when the same rack is used. When possible, she also suggests storing similar-appearing sterile and unsterile supplies on different racks or different shelves of the same rack.

4. What sterile technique practices affect wound classification? 
The wound classification should be determined at the end of the procedure by the interdisciplinary personnel in the room using a health care organization-approved method, such as the AORN Surgical Wound Classification Decision Tree. The wound class depends on the type of procedure performed and the presence of infection or contamination in the surgical site, Cahn explains.

For example: If an unsterile instrument set is used, open cardiac massage is performed, or an unsterile item (such as the surgeon’s eyeglasses) falls into the wound, the surgical wound classification would be ‘Class III-Contaminated’ because these are major breaks in sterile technique.

Recommended practice: When you aren’t certain if an event meets the criteria to be considered a major break in technique, Cahn suggests discussing the event details with an interdisciplinary team including the surgeon, perioperative leadership, and an infection preventionist.