5 - Surgical Prophylaxis Flashcards
What is a surgical site infection?
Superficial or deep incisional or organ/space infection w/in 30 days of surgery or w/in 1 year of placement of prosthetic implant
What is important about surgical site infections?
- Increase hospital stay
- 5x re-admission
- 2-3x mortality
What are the most important patient-related risk factors for SSIs?
- Advanced age, obesity, malnutrition
- Hypoxia associated w/ smoking or COPD
- Diabetes, perioperative hyperglycemia
- Immunocompromised (especially HIV or HCV)
- Co-existing infection
- Colonization w/ resident organism
What are the most important surgery-related risk factors for SSIs?
- Infection control processes or sterilization and ventilation; equipment and technique
- Surgical wound classification
- Intraoperative thermoregulation, glucose control, O2 supplementation
- Placement of foreign material
- Duration and type of surgery
What is a clean surgical wound?
- No mucosal incision or entry to respiratory, GI, or GU tracts
- No inflammation/infection
- Primarily closure
What is a clean-contaminated surgical wound?
Mucosal incision or entry to respiratory, GI, GU tract w/o unusual contamination
What is a contaminated surgical wound?
- Acute wound/trauma
- Non-purulent inflammation
- Major break in sterile technique/ spillage
What is a dirty surgical wound?
- Chronic wound
- Perforated viscera
- Purulent inflammation/ infection
- Warrants antimicrobial therapy
What are the most common pathogens associated w/ SSIs?
- Staph aureus
- Streptococcus spp
- CoNS, most commonly staph epidermidis
- E. coli, Klebsiella, enterobacter, P. aeruginosa
When is E. coli most often associated w/ an SSI?
In urinary tract and gut surgeries
When is pseudomonas most often associated w/ an SSI?
Immunocompromised px previously on broad spectrum antibiotics
When is enterococcus most often associated w/ an SSI?
Immunocompromised pt w/ GI surgery (usually not pathogenic in wound infections unless the pt is immunocompromised)
What is the goal of antimicrobial prophylaxis for surgery?
- Reduce bacterial burden at incision site
- Prevent SSIs and associated pt morbidity, mortality, and healthcare costs
- Minimize collateral resistance (MRSA, ESBL, VRE)
- Avoid antimicrobial-associated adverse effects including C. difficile
What are the optimal characteristics for antimicrobial prophylaxis for surgery?
- Bactericidal w/ spectrum that covers most likely pathogens, but sufficiently narrow to minimize collateral resistance
- PK to provide adequate tissue concentrations for duration of surgery from incision to closure
- High safety profile
- Cost effective
What are some institutional initiatives that may improve delivery of optimal antimicrobial prophylaxis for surgery?
- Education
- Standardized guidelines for timing of preoperative dose w/in 1 h of incision, re-dosing during surgery as required and limiting duration
- Audits and reporting of performance, compliance and outcomes
Which antibiotics are the most commonly prescribed for surgical prophylaxis and why?
- Cephalosporins
- Broad spectrum, favourable PK profile, low adverse effects, and low cost
What are some generalizations that can be made about the antibiotics used for surgical prophylaxis?
- First gen cephalosporins (like cefazolin) are preferred choice (used when targeting skin microbes)
- Vanco is used for procedures involving implantation of a prosthetic device in which the rate of MRSA is high
- If MRSA risk is low and a beta-lactam allergy exists, clinda is used
What is important to remember during cardiac surgery?
- Pt is attached to a bypass machine so the heart isn’t beating, which drastically increases the Vd of the pt
- Should consider giving a higher dose, dosing more frequently, or using a continuous infusion
