CRNFA Wound Closure and Healing 2 — Questions and Answers
Question 1: Which patient factor is the single greatest systemic risk factor for surgical site infection?
- Age over 65
- Uncontrolled diabetes mellitus (HbA1c > 8%) (Correct answer)
- Obesity (BMI > 30)
- Smoking within the past year
Correct answer: Uncontrolled diabetes mellitus (HbA1c > 8%)
Uncontrolled diabetes mellitus impairs leukocyte function, reduces tissue perfusion, and provides a glucose-rich environment for bacterial growth, making it the strongest systemic SSI risk factor.
Question 2: Which absorbable suture retains the most tensile strength at 6 weeks postoperatively?
- Plain gut
- Chromic gut
- Polyglycolic acid (Dexon)
- Polydioxanone (PDS II) (Correct answer)
Correct answer: Polydioxanone (PDS II)
PDS II (polydioxanone) retains approximately 50% tensile strength at 6 weeks and 25% at 6 months, outlasting all other common absorbable sutures.
Question 3: Dead space in a wound is most dangerous because it:
- Increases wound tension on the skin
- Collects serum and blood that serve as a bacterial culture medium, promoting infection and seroma (Correct answer)
- Prevents re-epithelialization
- Causes excessive fibrosis
Correct answer: Collects serum and blood that serve as a bacterial culture medium, promoting infection and seroma
Dead space allows fluid accumulation, creating a seroma or hematoma that is an ideal medium for bacterial growth and dramatically increases infection and dehiscence risk.
Question 4: When closing a laparotomy fascial layer, which suture placement technique is recommended to reduce the risk of wound dehiscence?
- Simple interrupted sutures placed 1 cm apart and 1 cm from the edge
- Small bites technique — sutures placed 5 mm from edge and 5 mm apart in a continuous fashion (Correct answer)
- Figure-of-eight sutures placed 2 cm from the edge
- Running locking sutures placed as close to the edge as possible
Correct answer: Small bites technique — sutures placed 5 mm from edge and 5 mm apart in a continuous fashion
The small bites technique (STITCH trial) using 5 mm bite size and 5 mm spacing in a running fashion significantly reduces incisional hernia and dehiscence compared to large bites.
Question 5: A patient develops a seroma 10 days after a mastectomy. The CRNFA understands that the most common contributing factor is:
- Wound infection with S. aureus
- Lymphatic and small blood vessel disruption during flap creation leading to fluid accumulation (Correct answer)
- Use of absorbable sutures in the wound
- Excessive postoperative activity
Correct answer: Lymphatic and small blood vessel disruption during flap creation leading to fluid accumulation
Mastectomy seromas form when lymphatic and small vessels in the dissection planes continue to weep serous fluid into the dead space beneath skin flaps.
Question 6: Which wound closure device provides the fastest skin closure and lowest rate of tissue strangulation in linear wounds?
- Interrupted monofilament sutures
- Skin staples (Correct answer)
- Subcuticular absorbable suture
- Steri-Strips (skin closure tapes)
Correct answer: Skin staples
Skin staples provide the fastest mechanical closure with minimal tissue handling and low risk of strangulation because they do not incorporate tissue within a loop under tension.
CRNFA Wound Closure and Healing 2
Which patient factor is the single greatest systemic risk factor for surgical site infection?