Chapter 26- Surgical Infection- Wound/Surgical Site Infection

Question 1

What is it?

Answer 1

Infection in an operative wound

Question 2

When do these infections arise?

Answer 2

Classically, PODs #5 to #7

Question 3

What are the signs/symptoms?

Answer 3

• Pain at incision site
• erythema
• drainage
• induration
• warm skin
• fever

Question 4

What is the treatment?

Answer 4

• Remove skin sutures/staples
• rule out fascial dehiscence
• pack wound open
• send wound culture
• administer antibiotics

Question 5

What are the most common bacteria found in postoperative wound infections?

Answer 5

• S. aureus (20%)
• E. coli (10%)
• Enterococcus (10%)
• Other causes:
  
  • Staphylococcus epidermidis
  • Pseudomonas
  • anaerobes
  • other gram-negative organisms
  • Streptococcus

Question 6

Which bacteria causes fever and wound infection in the first 24 hours after surgery?

Answer 6

• Streptococcus
• Clostridium (bronze-brown weeping tender wound)

Question 7

What is a “clean” wound?

Answer 7

Elective, nontraumatic wound without acute inflammation; usually closed primarily without the use of drains

Question 8

What is the infection rate of a clean wound?

Answer 8

<1.5%

Question 9

What is a clean-contaminated wound?

Answer 9

Operation on the GI or respiratory tract without unusual contamination or entry into the biliary or urinary tract

Question 10

Without infection present, what is the infection rate of a clean-contaminated wound?

Answer 10

<3%

Question 11

What is a contaminated wound?

Answer 11

• Acute inflammation
• traumatic wound
• GI tract spillage
• or a major break in sterile technique

Question 12

What is the infection rate of a contaminated wound?

Answer 12

≈5%

Question 13

What is a dirty wound?

Answer 13

• Pus present
• perforated viscus
• or dirty traumatic wound

Question 14

What is the infection rate of a dirty wound?

Answer 14

≈33%

Question 15

What factors influence the development of infections?

Answer 15

• Foreign body (e.g., suture, drains, grafts)
• Decreased blood flow (poor delivery of PMNs and antibiotics)
• Strangulation of tissues with excessively tight sutures
• Necrotic tissue or excessive local tissue destruction (e.g., too much Bovie)
• Long operations (>2 hrs)
• Hypothermia in O.R.
• Hematomas or seromas
• Dead space that prevents the delivery of phagocytic cells to bacterial foci
• Poor approximation of tissues

Question 16

What is the treatment?

Answer 16

• Incision and drainage—an abscess must be drained (Note: fluctuation is a sign ofa subcutaneous abscess; most abdominal abscesses are drained percutaneously)
• Antibiotics for deep abscesses

Question 17

What are the indications for antibiotics after drainage of a subcutaneous abscess?

Answer 17

• Diabetes mellitus
• surrounding cellulitis
• prosthetic heart valve
• or animmunocompromised state