Wound classification, infection and antimicrobial use Flashcards
Surgical wound are classified by degree of what?
Contamination
What does classification of surgical wounds predict?
Likelihood of infection
What number of organisms must be present in order to diagnose a bacterial infection?
> 100,000 organisms/gram of tissue
What are the 4 classifications of surgical wounds?
- Clean
- Clean contaminated
- Contaminated
- Dirty
T/F: A clean wound is a non-traumatic, non-infected operative wound
TRUE
In order to be classified as a clean wound, which tracts must NOT be entered? Examples?
Oropharyngeal, GIT, urinary, and respiratory tracts not entered
Ex: exploratory, neuter
What is a clean contaminated wound? What are some examples?
Clean wound in which tract is penetrated
No gross contamination
Ex: gastrotomy, hole in glove detected
Which wound classification does this describe:
Traumatic wound
No purulent discharge
Spillage of GIT contents or urine
Major aseptic break
Contaminated
What are two examples of a contaminated sx wound?
Bile spillage
Touched mask
Can a contaminated wound be converted to a clean contaminated wound?
Yes–early debridement and lavage can convert them
What classifies as dirty wounds?
- Infected wounds
- Wounds with pus
- Perforated hollow viscus
- > 100,000 organisms/gram of tissue
A ruptured stomach and cat fight abscess classify as which type of wound?
Dirty
T/F: All surgical wounds are contaminated by bacteria
TRUE
What is the incidence of infection for surgical wounds?
5%
What is the goal of aseptic technique?
Minimize the incidence of surgical wound infection
What are the degrees of bacterial contamination for each wound classification (percentages)?
- Clean = 0-4.8%
- Clean contaminated = 3.5-5%
- Contaminated = 4.6-12%
- Dirty = implies infection
How does clipping at the surgical site increase risk of contamination? How can you minimize that risk?
Leaves nicks in skin–>allows bacteria to colonize
Only clip immediately pre-operatively
T/F: normal wound healing enhances the immune system
FALSE–it suppresses the immune system
How can longer surgeries increase risk of infection?
- Tissue trauma
- Suture/hemostasis
- Environmental exposure
T/F: For duration of both surgery and anesthesia, risk of infection doubles every hour
TRUE
Can prolonged exposure to anesthetic drugs suppress immunity?
YES
T/F: Anesthetic drugs don’t have any chances of becoming contaminated
FALSE–some drugs are eaily contaminated
Ex: propofol can support microbial growth
What 3 endocrinopathies are risk factors for infection?
Diabetes mellitus
Hyperadrenocorticism
Hypothyroidism
Which sex has a higher risk factor for infection? Why?
Intact male cats and dogs
Androgens effect on the immune system
T/F: The higher number of people in the OR, the higher the chance of infection in the patient
TRUE
T/F: Supplemental oxygen may increase the risk of surgical wound infection
FALSE
What is the difference between prophylactic and therapeutic antibiotics?
- Prophylactic
- Use of an antibiotic to protect a patient from an anticipated bacterial invasion
- Administered prior to wound contamination
- Use of an antibiotic to protect a patient from an anticipated bacterial invasion
- Therapeutic
- Infection already exists and needs to be treated
When should prophylactic antibiotics be used?
Examples?
- 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
Which is preferred when selecting antibiotics: -static or -cidal?
-cidal
What bac. and antibiotic choice occurs in clean procedures?
Staphylococcus
Cephazolin
What bac. and antibiotic choice occurs in clean contaminated procedures of the upper GIT?
Enterococci
Cephazolin
What bac. and antibiotic choice occurs in clean contaminated wounds of the cecum and colon?
Anaerobes
Cefotoxin 2nd generation
What is the goal of correct timing of prophylactic antibiotics?
To achieve highest concentrations at start of and duration of surgery
When should prophylactic antibiotics be administered?
1 hour prior
Repeat every 2 hours during surgery
When should prophylactic antibiotics NOT be delivered? Why? Is there an exception?
- Do not administer beyond 24 hrs post surgery
- Alters organism susceptibility
- Increases infection rates
- Unless gross contamination
- Prophylactic becomes therapeutic
When are preventative antibiotics used in surgery?
- Intraoperative use when unexpected contamination occurs
- Spillage of intestinal contents
- Surgery longer than expected (>90 min)
T/F: Intraoperative prevetative antibiotic use has been proven to be beneficial
FALSE
What are the indications for therapeutic antibiotics?
Systemic infection
Surgical site infection
Any contaminated or dirty procedure
What should therapeutic antibiotic choice be based on? When should it be given?
Based on C/S
Start prior to surgery and continue >2-3 days post surgery
How can you minimize post-operative infections?
Use glove and wash hands
Protect/clean incisions
Drains and catheters
