Revision 4, SSI and use of antibiotics Flashcards
Classification of surgical wounds
- Classified by degree of contamination – help predict the likelihood of infection
- Having more than 10x5 bacteria per gram of tissue → bacterial infection
- Infection rate for all types of surgical wounds approximately 5%
- 4 categories
Clean
- Inf rate 0-6%
- AB not warranted
- Prophylactic AB appear to be indicated in some clean procedures
(orthopedic implants) - Given at induction (30-60min prior to incision)
- Discontinued within 24 hours of the procedure (at the end of
surgery) - Most likely postoperative infection
- Severe trauma with multiple fractures
- Traumatic procedures
- Orthopedic surgeries
Clean-contaminated
- Minor break in aseptic technique
- Inf rate 4.5-9.3%
- Antimicrobial prophylaxis indicated
- Choice of AB based on anticipated flora
- Most likely postoperative infection
- Clean-contaminated fractures of the pelvis and long bones
Contaminated
- Not infected initially, but have potential
- Inf rate 5.8-28.6%
- Antimicrobial prophylaxis indicated
- Choice of AB based on anticipated flora → then modified according to culture and sensitivity results
- Most likely postoperative infection
- Contaminated fractures of the pelvis and long bones
- Contaminated urogenital procedures - Delicate debridement, copious (runsas) lavage, antibiotic therapy → clean wound
- Inadequate therapy → dirty wound
Dirty
- Gross infection present at the time of surgical intervention
- Traumatic wounds with retained devitalized tissue, foreign bodies,
fecal contamination - AB therapy, later modified according to culture and sensitivity
results - Copious lavage, debridement
Do you use prophylactic or therapeutic ABs in case of clean wound?
Usually neither, in some cases prophylactic
E.g. Despite being a clean wound, the use of prophylactic antibiotics is indicated due to the nature of the surgery involving implantation of a prosthetic device.
Do you use prophylactic or therapeutic ABs in case of clean-contaminated wound?
Prophylactic
E.g. Prophylactic antibiotics are indicated because the procedure involves entering a potentially contaminated area
Do you use prophylactic or therapeutic ABs in case of contaminated wound?
Both are possible
Scenario: A dog presents with a compound fracture with extensive soft tissue damage after being hit by a car. The fracture is classified as contaminated due to exposure to environmental debris.
Management: Prophylactic antibiotics are administered before surgery to reduce the risk of infection during fracture repair.
Scenario: A cat develops a deep abscess after being bitten by another cat. The wound becomes swollen, painful, and starts to discharge pus.
Management: Therapeutic antibiotics are initiated based on culture and sensitivity results to treat the established infection in the contaminated wound.
Do you use prophylactic or therapeutic ABs in case of dirty wound?
Prophylactic so and so, maybe if started earlier.
Therapeutic yes.
Scenario: A horse develops cellulitis and abscessation at the site of a puncture wound on its leg. The wound is swollen, painful, and discharging purulent material.
Management: Therapeutic antibiotics are initiated based on culture and sensitivity results to treat the established infection in the dirty wound.
Classification of SSIs
- With primary surgical disease
- As a complication of a surgical procedure not commonly associated with infection
*As a complication of a support procedure
*With prosthetic implants
SSI: With primary surgical disease
- Nonsterile source (skin, GI tract, urinary tract)
- Subject only to surgical treatment not surgical prevention
- AB based on expected bacterial flora – then modified if necessary
- Osteomyelitis secondary to open fracture, pyometra, prostatic
abscessation
SSI: As a complication of a surgical procedure not commonly associated with infection
- All surgical procedures cause some bacterial contamination!
- Development of infection?
- Number and virulence of the bacteria
- Competence of host defenses
- Amount of tissue damage
- Amount of dead space resulting from the procedure - Infections can be minimized!
E.g. SSI occurs as a complication of a spay surgery, which is not commonly associated with infections due to its clean nature and routine performance
SSI: As a complication of a support procedure
- Weakened, traumatized, immunocompromised patients
- Intravenous catheters
- Cephalic catheters changed every 48 to 72 h
- Jugular catheters changed every 7 to 10 days - Urinary catheters
- Common source of infection after 2-3 days - Prolonged endotracheal intubation
- Foreign body, disrupted cough reflex
SSI: With prosthetic implants
- Foreign material in contaminated/infected wounds increase chance for chronic infection
- AB treatment seldom successful until implant removed
- Aseptic technique, AB prophylaxis – infection, implant rejection rare
- Nonabsorbable suture, polypropylene mesh, TTA
What is the primary objective of aseptic surgery?
Prevention of surgical infections
