Surgical Asepsis, Sterile Field and Sharps Safety

Principles of Surgical Asepsis and Field Integrity

Surgical asepsis, also referred to as sterile technique, is the practice of maintaining an area or object completely free of all microorganisms, including bacterial spores. In contrast to medical asepsis which reduces microbial load, sterilization is the specific process that completely eliminates all microorganisms and spores. A sterile object remains sterile only when it is touched exclusively by another sterile object. Contact between a sterile object and any nonsterile object causes immediate contamination, rendering the item unsafe for invasive procedures.

To guarantee that an item remains uncontaminated, sterile items must be kept in continuous sight by the nurse. Turning one's back on a sterile field or walking away from it renders the field contaminated, as unobserved breaches could occur. Furthermore, spatial boundaries are strictly defined by body mechanics: any sterile object or gloved hand held below the nurse's waist level is considered contaminated. When not actively working on the field, the nurse must keep gloved sterile hands held together in front of the body and positioned above waist level.

The surrounding atmosphere also poses a risk to sterile integrity. Nurses must actively minimize a sterile field's exposure to air currents, because circulating air can carry microorganisms directly onto sterile surfaces. Talking, sneezing, or coughing over an uncovered sterile field can contaminate it; avoid reaching over the field because doing so risks introducing contaminants. For example, leaning across a sterile tray to pick up gauze on the opposite side introduces microbes from clothing or skin shedding onto the sterile surface below.

Physical borders and moisture dynamics also define field boundaries. The outer one-inch border of a sterile drape or wrapper is considered nonsterile, establishing a safety margin between the nonsterile clinical environment and the sterile working zone. Additionally, any portion of a sterile drape that hangs over the edge of a table is considered contaminated. Moisture is an equally critical hazard: capillary action from moisture soaking through a sterile wrapper contaminates the sterile surface by drawing organisms through the barrier. If a sterile field becomes wet or a sterile barrier is breached in any way, the nurse must discard the entire setup and restart.