Asepsis in healthcare refers to the practices that help prevent infection by eliminating or reducing microorganisms. This concept is divided into two primary categories: medical asepsis and surgical asepsis. Surgical asepsis, also known as sterile technique, is the most rigorous form of infection control. It is defined as the complete elimination of all microorganisms and their spores from an area or object. This high level of sterility is required during any procedure that involves entering a sterile body cavity or when the integrity of the skin is compromised, such as during an operation or the insertion of a device into the body.
Surgical Asepsis Versus Clean Technique
Healthcare professionals use different levels of cleanliness depending on the risk of contamination during a procedure. Medical asepsis, often called clean technique, focuses on reducing the number of microorganisms and preventing their spread. Standard practices like routine hand hygiene, using disinfectants, and wearing clean gloves for non-invasive procedures fall under medical asepsis.
Surgical asepsis, by contrast, aims to create an environment entirely free of microorganisms, including bacterial spores. This sterile technique is reserved for invasive procedures where the body’s natural defenses are bypassed. The distinction is based on the goal: medical asepsis reduces the microbial count, while surgical asepsis eliminates it entirely. The nurse must choose the appropriate technique based on the procedure’s invasiveness.
Essential Rules for Maintaining Sterility
Maintaining a sterile field requires strict adherence to universal principles. The first principle is that a sterile object remains sterile only when touched by another sterile object. This means sterile instruments or materials must only be handled with sterile gloves or sterile transfer forceps.
Once a sterile field is established, all sterile items must be kept above the nurse’s waist and within their line of sight. If a sterile item falls below the waist level or is turned away from, its sterility is immediately questioned. The outer one-inch border of a sterile field is considered contaminated because it is exposed to the surrounding non-sterile environment.
A sterile field can never be exposed to moisture, as liquid allows microorganisms to “wick” or travel from a non-sterile surface to a sterile one. Surfaces must be dry before sterile drapes are placed. Non-sterile personnel must never reach across a sterile field, and sterile personnel must avoid turning their back to the field. If there is any doubt about the sterility of an item or the field, the nurse must dispose of the item or reset the field immediately.
Practical Application: A Common Sterile Procedure
A common example of a nurse using surgical asepsis is the insertion of an indwelling urinary catheter, often called a Foley catheter. This procedure requires sterile technique because the catheter is inserted through the urethra into the sterile urinary bladder. The nurse first performs hand hygiene and opens the outer packaging of the catheterization kit, touching only the outside wrapper.
The nurse establishes the sterile field by placing the inner-wrapped tray on a clean surface and opening the flaps outward, ensuring non-sterile hands only touch the outer surface of the flaps. The nurse then carefully dons sterile gloves, which are packaged inside the kit, touching only the inside cuff of the first glove. Once the sterile gloves are on, the nurse’s hands are considered sterile and can manipulate the kit contents.
The nurse uses the sterile gloves to handle the sterile drapes, placing a fenestrated drape over the patient’s perineum to isolate the insertion area. The nurse then uses sterile antiseptic swabs from the kit to cleanse the urinary meatus. Wiping must proceed from the cleanest area to the dirtiest, and each swab is discarded immediately after a single pass to remove microorganisms before the sterile catheter is introduced.
During insertion, the nurse’s dominant, sterile hand handles the catheter. The non-dominant hand may become contaminated when it touches the patient to stabilize the area. This non-dominant hand must then remain fixed, as it is no longer sterile, preventing contamination of the catheter or kit contents. The catheter is inserted until urine is observed and advanced further to inflate the balloon within the bladder, preventing a catheter-associated urinary tract infection.