Wound classification, infection and antimicrobial use

Question 1

Surgical wound are classified by degree of what?

Answer 1

Contamination

Question 2

What does classification of surgical wounds predict?

Answer 2

Likelihood of infection

Question 3

What number of organisms must be present in order to diagnose a bacterial infection?

Answer 3

> 100,000 organisms/gram of tissue

Question 4

What are the 4 classifications of surgical wounds?

Answer 4

1. Clean
2. Clean contaminated
3. Contaminated
4. Dirty

Question 5

T/F: A clean wound is a non-traumatic, non-infected operative wound

Answer 5

TRUE

Question 6

In order to be classified as a clean wound, which tracts must NOT be entered? Examples?

Answer 6

Oropharyngeal, GIT, urinary, and respiratory tracts not entered

Ex: exploratory, neuter

Question 7

What is a clean contaminated wound? What are some examples?

Answer 7

Clean wound in which tract is penetrated

No gross contamination

Ex: gastrotomy, hole in glove detected

Question 8

Which wound classification does this describe:

Traumatic wound

No purulent discharge

Spillage of GIT contents or urine

Major aseptic break

Answer 8

Contaminated

Question 9

What are two examples of a contaminated sx wound?

Answer 9

Bile spillage

Touched mask

Question 10

Can a contaminated wound be converted to a clean contaminated wound?

Answer 10

Yes–early debridement and lavage can convert them

Question 11

What classifies as dirty wounds?

Answer 11

• Infected wounds
• Wounds with pus
• Perforated hollow viscus
• > 100,000 organisms/gram of tissue

Question 12

A ruptured stomach and cat fight abscess classify as which type of wound?

Answer 12

Dirty

Question 13

T/F: All surgical wounds are contaminated by bacteria

Answer 13

TRUE

Question 14

What is the incidence of infection for surgical wounds?

Answer 14

5%

Question 15

What is the goal of aseptic technique?

Answer 15

Minimize the incidence of surgical wound infection

Question 16

What are the degrees of bacterial contamination for each wound classification (percentages)?

Answer 16

• Clean = 0-4.8%
• Clean contaminated = 3.5-5%
• Contaminated = 4.6-12%
• Dirty = implies infection

Question 17

How does clipping at the surgical site increase risk of contamination? How can you minimize that risk?

Answer 17

Leaves nicks in skin–>allows bacteria to colonize

Only clip immediately pre-operatively

Question 18

T/F: normal wound healing enhances the immune system

Answer 18

FALSE–it suppresses the immune system

Question 19

How can longer surgeries increase risk of infection?

Answer 19

• Tissue trauma
• Suture/hemostasis
• Environmental exposure

Question 20

T/F: For duration of both surgery and anesthesia, risk of infection doubles every hour

Answer 20

TRUE

Question 21

Can prolonged exposure to anesthetic drugs suppress immunity?

Answer 21

YES

Question 22

T/F: Anesthetic drugs don’t have any chances of becoming contaminated

Answer 22

FALSE–some drugs are eaily contaminated

Ex: propofol can support microbial growth

Question 23

What 3 endocrinopathies are risk factors for infection?

Answer 23

Diabetes mellitus

Hyperadrenocorticism

Hypothyroidism

Question 24

Which sex has a higher risk factor for infection? Why?

Answer 24

Intact male cats and dogs

Androgens effect on the immune system

Question 25

T/F: The higher number of people in the OR, the higher the chance of infection in the patient

Answer 25

TRUE

Question 26

T/F: Supplemental oxygen may increase the risk of surgical wound infection

Answer 26

FALSE

Question 27

What is the difference between prophylactic and therapeutic antibiotics?

Answer 27

* Prophylactic * Use of an antibiotic to protect a patient from an anticipated bacterial invasion * Administered **prior** to wound contamination * Therapeutic * Infection already exists and needs to be treated

Question 28

When should prophylactic antibiotics be used? Examples?

Answer 28

* If risk of infection is relatively high * Many clean contaminated procedure * Contaminated procedures * Patient factors (pre-existing prosthesis) * Type and length of sx (\>90 min) * Surgeon experience * When an infection would be disastrous * Ex: total hip replacement

Question 29

Which is preferred when selecting antibiotics: -static or -cidal?

Answer 29

**-cidal**

Question 30

What bac. and antibiotic choice occurs in clean procedures?

Answer 30

Staphylococcus Cephazolin

Question 31

What bac. and antibiotic choice occurs in clean contaminated procedures of the upper GIT?

Answer 31

Enterococci Cephazolin

Question 32

What bac. and antibiotic choice occurs in clean contaminated wounds of the cecum and colon?

Answer 32

Anaerobes Cefotoxin 2nd generation

Question 33

What is the goal of correct timing of prophylactic antibiotics?

Answer 33

To achieve highest concentrations at start of and duration of surgery

Question 34

When should prophylactic antibiotics be administered?

Answer 34

1 hour prior Repeat every 2 hours during surgery

Question 35

When should prophylactic antibiotics NOT be delivered? Why? Is there an exception?

Answer 35

* Do not administer beyond 24 hrs post surgery * Alters organism susceptibility * Increases infection rates * Unless gross contamination * Prophylactic becomes therapeutic

Question 36

When are preventative antibiotics used in surgery?

Answer 36

* Intraoperative use when unexpected contamination occurs * Spillage of intestinal contents * Surgery longer than expected (\>90 min)

Question 37

T/F: Intraoperative prevetative antibiotic use has been proven to be beneficial

Answer 37

FALSE

Question 38

What are the indications for therapeutic antibiotics?

Answer 38

Systemic infection Surgical site infection Any contaminated or dirty procedure

Question 39

What should therapeutic antibiotic choice be based on? When should it be given?

Answer 39

Based on C/S Start prior to surgery and continue \>2-3 days post surgery

Question 40

How can you minimize post-operative infections?

Answer 40

Use glove and wash hands Protect/clean incisions Drains and catheters