3.6 Surgical Asepsis and Sterile Technique

Sterile Means Zero Microorganisms

The NCLEX-PN distinguishes medical asepsis (clean), which reduces organisms, from surgical asepsis (sterile), which eliminates them. Sterile technique is mandatory whenever the body's natural barriers are bypassed.

When Sterile Technique Is Required

Surgical site infections, catheter-associated urinary tract infections (CAUTI), and central-line bloodstream infections are largely preventable, and sterile technique is the front-line defense. The LPN/LVN must know that the moment any barrier is breached, microorganisms can be introduced directly into normally sterile tissue, so the standard is perfection, not "good enough."

Core Principles of a Sterile Field

1. Sterile touches only sterile. Sterile-to-unsterile contact contaminates.
2. The outer 1-inch border is contaminated. Only the top surface of the drape is sterile; below the table edge is unsterile.
3. When in doubt, throw it out. Any questioned item is contaminated.
4. Keep sterile items in sight and above the waist. Items below the waist or out of view are contaminated.
5. Moisture wicks contamination. A wet field draws bacteria up by capillary action ("strike-through").
6. Never reach over or turn your back on the field. Pass behind others; do not reach across.

Setting Up and Adding to the Field

Place the package on a clean, dry surface at waist level or higher. Open the far flap first, then the side flaps, then the nearest flap last — this keeps your arms from crossing the sterile contents. To add an item, peel the wrapper and drop it onto the center, staying clear of the 1-inch border.

Sterile (Open) Gloving

Contamination occurs if a bare hand touches the glove exterior, a gloved hand touches skin or a non-sterile surface, or the glove tears or is punctured. Hold gloved hands above the waist and in front of the body at all times once gloved, and clasp them together when not actively working to avoid accidental contact. If either glove is contaminated during donning, discard the pair and start over with a new package — partial fixes are not acceptable.

Sterile Procedures: Catheter and Wound Care

For urinary catheterization, clean the periurethral area with one swab per stroke, wiping front to back in females, and insert with the dominant sterile hand, keeping the non-dominant hand on the labia/penis as the now-contaminated hand. For wound cleaning, move from least to most contaminated: a clean wound is cleaned center-to-periphery, while a contaminated/infected wound is cleaned periphery-to-center, using each swab only once.

Dressing Change Sequence

1. Remove the old dressing with clean gloves; assess drainage.
2. Remove gloves and perform hand hygiene.
3. Set up the sterile field and don sterile gloves.
4. Clean the wound by aseptic technique and apply the new sterile dressing.

Worked Example

Mid-procedure, a sterile 4x4 gauze slips off the field onto the floor. The correct action is to leave it and open a new sterile gauze — touching a non-sterile surface contaminates it, and no amount of alcohol restores sterility.

Surgical Hand Antisepsis and the Sterile Gown

Before donning sterile attire for a surgical setting, perform a surgical scrub: a longer (often 2-5 minute) antiseptic wash extending from fingertips to elbows, holding the hands above the elbows so water drains away from the cleanest area (the hands) toward the elbows. After scrubbing, dry with a sterile towel and don the sterile gown and gloves by closed gloving when a sterile gown is worn, keeping hands inside the cuffs until the gloves are in place.

Once gowned and gloved, the sterile zone is from the chest to the level of the sterile field and the sleeves from the cuff to about 2 inches above the elbow — the back of the gown, the axillae, and anything below the waist are not considered sterile.

Why the Order and Sight Rules Matter

Reaching across a sterile field drops skin cells and lint onto the items below; turning your back means you cannot detect a contamination event. These rules are tested because they are concrete: if a scenario describes a nurse turning away to answer a phone, leaving the field unattended, or coughing over the field, the correct interpretation is that the field is contaminated and must be re-set with fresh supplies.

Common NCLEX-PN Traps

• Believing alcohol can re-sterilize a dropped item.
• Reaching across the sterile field.
• Cleaning an infected wound center-to-periphery (reverse of the clean-wound rule).
• Treating the entire drape — including the 1-inch border — as sterile.