NCMA Surgical Asepsis and Sterile Technique 1 — Questions and Answers
Question 1: What is the fundamental difference between medical asepsis and surgical asepsis?
- Medical asepsis is used in hospitals; surgical asepsis is used in outpatient clinics
- Medical asepsis reduces the number of microorganisms; surgical asepsis eliminates ALL microorganisms from objects and areas to prevent infection (Correct answer)
- Surgical asepsis only applies to surgical procedures; medical asepsis applies to all other procedures
- They are interchangeable terms for infection control practices
Correct answer: Medical asepsis reduces the number of microorganisms; surgical asepsis eliminates ALL microorganisms from objects and areas to prevent infection
Medical asepsis (clean technique) reduces the number of microorganisms to prevent their spread. Surgical asepsis (sterile technique) eliminates all microorganisms and spores from instruments and fields to prevent any introduction of organisms into the body.
Medical asepsis (clean technique): reduces number of microorganisms and prevents their spread; examples: handwashing, wearing gloves, cleaning surfaces, proper waste disposal. Surgical asepsis (sterile technique): maintains a completely sterile environment — no microorganisms of any kind; used when entering body cavities or performing invasive procedures; requires: sterilized instruments, sterile gloves, sterile drapes, sterile field maintenance. Principles of surgical asepsis: sterile touches only sterile; anything below waist level or out of sight is contaminated; if in doubt, consider it contaminated; sterile fields become contaminated with time and moisture; non-sterile persons stay outside the sterile field perimeter.
Question 2: When opening a sterile package to add its contents to a sterile field, what is the correct technique?
- Tear open the packaging quickly and drop the item onto the sterile field
- Open the outer wrap away from you first, then sides, then toward you, without reaching over the sterile field; allow item to fall or flip onto field (Correct answer)
- Open all four flaps simultaneously and place the item directly on the field with gloved hands
- Peel open the package and pass it over the sterile field to a sterile-gloved assistant
Correct answer: Open the outer wrap away from you first, then sides, then toward you, without reaching over the sterile field; allow item to fall or flip onto field
To open a sterile package without contaminating the field: open the top flap away from you, then the two side flaps, then the front flap toward you — never reaching over the sterile field. Allow the item to drop or flip onto the field; do not let the wrapper touch the field.
Opening sterile packages onto the sterile field: The sequence (first flap away from you, then sides, then toward you) prevents the non-sterile outer wrapper from passing over the sterile contents. Rules: (1) Inspect packaging for integrity — no tears, moisture, or expiration; (2) Open firmly without touching the inner contents with ungloved hands; (3) The inner wrapper forms a sterile boundary — the outer wrapper is NOT sterile; (4) For pouched items (peel-apart pouches): peel back the flap with both hands, pulling edges away from each other — do not allow your hands or non-sterile portions to contaminate the field; (5) Flipping method: fold wrapper back over hands and flip item onto field; (6) Transfer by sterile gloved assistant: hold package open and let sterile-gloved person retrieve item.
Question 3: During a minor surgical procedure, the medical assistant accidentally drops a sterile instrument below the level of the sterile drape. What should be done?
- Retrieve the instrument and wipe it with an alcohol swab before returning it to the field
- Consider the instrument contaminated; do not use it; replace with a sterile instrument (Correct answer)
- Rinse the instrument with sterile saline and return it to the field
- Continue using the instrument since it only touched the floor briefly
Correct answer: Consider the instrument contaminated; do not use it; replace with a sterile instrument
Items that fall below the level of the sterile field — especially to the floor — must be considered contaminated regardless of contact duration. Sterile fields maintain a height standard: items below waist level are considered non-sterile.
Sterile field rules — when sterility is compromised: (1) Below waist/table level — any item dropped below the sterile field level is immediately considered contaminated (gravity and environmental microorganisms); (2) Moisture — a wet sterile drape becomes a pathway for microorganism migration (strike-through contamination); (3) Out of visual field — items that leave the line of sight are considered potentially contaminated; (4) Time — sterile fields should not be set up too far in advance; (5) Touch — non-sterile items touching sterile items = contaminated. When contamination occurs: do not use the item; do not return to sterile field; replace with a properly sterilized instrument; note the event in procedure documentation; do not proceed until the sterile field is re-established or replaced.
Question 4: Which sterilization method is most commonly used for surgical instruments in the medical office, and what are its key parameters?
- Dry heat oven at 320°F for 60 minutes for wrapped instruments
- Steam autoclave (moist heat under pressure) typically at 250°F (121°C) at 15 psi for 15–30 minutes depending on load (Correct answer)
- Chemical sterilization with glutaraldehyde for 3 hours in closed container
- Ethylene oxide gas at room temperature for 10 minutes
Correct answer: Steam autoclave (moist heat under pressure) typically at 250°F (121°C) at 15 psi for 15–30 minutes depending on load
Steam sterilization by autoclave is the most common, effective, and economical sterilization method for heat-stable instruments. Standard parameters: 250°F (121°C) at 15 psi for 15–30 minutes (longer for wrapped/heavier loads).
Autoclave steam sterilization: Uses saturated steam under pressure; destroys all microorganisms including spores. Standard gravity displacement cycle: 121°C (250°F), 15 psi, 15 min (unwrapped) / 30 min (wrapped); Pre-vacuum/high-speed cycle: 132°C (270°F), 27–30 psi, 4 min. Critical factors: temperature, pressure, time, steam saturation, air removal. Quality controls: Chemical indicators (color-change strips/tape) verify exposure to parameters; Biological indicators (Bacillus stearothermophilus spore strips) — definitive test run weekly or with each new load; Load preparation: instrument hinges open, single layer, don't overload. Cannot autoclave: plastics, rubber, certain delicate instruments → use EtO, plasma, or chemical sterilization instead.
Question 5: When donning sterile gloves using the open (closed glove) method, which hand is gloved first and why?
- The dominant hand, because it needs to be protected first for fine motor tasks
- The non-dominant hand first, using the contaminated ungloved hand to pick up the cuffed end; then the dominant hand using the sterile-gloved hand (Correct answer)
- Either hand can be gloved first; the order doesn't matter in sterile technique
- Both gloves must be put on simultaneously to prevent contamination
Correct answer: The non-dominant hand first, using the contaminated ungloved hand to pick up the cuffed end; then the dominant hand using the sterile-gloved hand
In the open glove method: using only the inner sterile surface (cuff), slip the dominant hand in first using the non-dominant hand. Then use the sterile-gloved dominant hand to pick up the second glove by sliding fingers under the outer cuff (sterile-to-sterile contact) for the non-dominant hand.
Open (individual) sterile gloving technique: (1) Open the sterile glove package without contaminating gloves; (2) Identify right and left gloves; (3) Using the non-dominant hand, grasp the folded cuff of the dominant hand glove (touching only the inside — not sterile surface); (4) Slip dominant hand into glove without touching outside of glove; (5) With the sterile-gloved dominant hand, slide 4 fingers under the cuff of the second glove (sterile-to-sterile contact only); (6) Slip non-dominant hand into second glove; (7) Adjust fit by touching only sterile surfaces. Contamination occurs if: outside of glove is touched by bare hand, gloves touch non-sterile surfaces, wrists are touched. The closed gloving method is used in the OR and keeps hands inside the gown sleeve throughout gloving.
Question 6: Which of the following actions would NOT contaminate a sterile field during a minor surgical procedure?
- Sneezing toward the sterile drape
- Placing a sterile instrument using sterile transfer forceps without touching the field border (Correct answer)
- Reaching across the sterile field to retrieve an instrument on the far side
- Allowing the patient to touch an instrument on the sterile field
Correct answer: Placing a sterile instrument using sterile transfer forceps without touching the field border
Using sterile transfer forceps to place an item onto the sterile field without crossing over the field or touching the border maintains sterility. This is the correct technique for adding instruments without contaminating the sterile field.
Sterile field contamination occurs with: airborne particles from talking, coughing, sneezing over field; reaching over sterile field (arm pass overhead = contamination zone above waist/table level); patient or non-sterile persons touching the field; moisture/strike-through; items falling below table level; non-sterile packaging touching the field. Sterile transfer forceps (ring forceps/Allis forceps): kept in sterile storage solution or autoclaved wrapped; can add items to field or arrange instruments without contaminating the field; tips must always remain below horizontal (if pointed up, solution can contaminate tips and drip down as non-sterile when tilted back down); replace in solution after each use or discard if taken out of solution. Sterile fields should be established as close to procedure start time as possible.
NCMA Surgical Asepsis and Sterile Technique 1
What is the fundamental difference between medical asepsis and surgical asepsis?