Lecture 37 Surgical site infections Flashcards
What are risk fx for surgical site infections (SSIs)?
coincident remote site infections or colonization
DM, smoking, systemic steroid use or other immunosuppressants, obesity, age extremes, malnutrition, perioperative transfusion
What are ways to help prevent SSIs?
sterile ORs with positive pressure
strict aseptic tech
Pt Prep: tx of pre-existing infections, shower with soap or antiseptic at least a night before surgery, adequate skin prep (hair clipping rather than shaving)
What are important aspects of SSI prophylaxis?
A: use agent shown to reduce SSIs for that type of surgery
B: use safe agent thats inexpensive and bactericidal with spectrum that covers most probables
C: time infusion so that conc of antibiotic of drug established in serum and tissues by time skin is incised
D: main therapeutic levels in serum and tissues until at most a few hours after incision closed
What is the best timing for prophylaxis for SSIs?
optimal timing within 60 min before surgical procedure for most antibacterials
fluoroquinolones and vancomycin require prolonged infusion times - infusion should begin within 2 hours of incision
What are the classifications of surgical wounds?
Class I: uninfected wound with no inflammation and the respiratory, alimentary, genital or uninfected UT is not entered
Class II: respiratory, alimentary, genital or uninfected UT entered under controlled circumstances without unusual contamination
Class III: open, fresh, accidental wounds, ruptured bowel
operations with major break in tech ex. spillage from GI, open cardiac massage
Class IV: old traumatic wounds with retained devitalized tissue, existing clinical infection or perforated viscera
obvious pre-existing infections present
What are the usual antibacterials chosen for SSI prophylaxis?
only necessary if significant risk of infection
cephalosporins best studied
CEFAZOLIN widely used (clindamycin or vancomycin chosen if serious cefazolin allergy)
surgery on distal GI tract requires agent that provides anaerobic coverage including B. fragilis - ex. cefoxitin or (cefazolin + metronidazole), alternative gentamicin + metronidazole OR clindamycin
3rd or 4th gen not routinely recommended
vanco really only used if high incidence of MRSA or MRSE post-operative infections, may be chosen in severe cefazolin allergy, should be chosen for pt with known MRSA colonization or at high risk for MRSA from surveillance data (ex. recent hospitalization, hemodialysis)
What is the recommended prophylaxis tx for SSI in abdominal laparoscopic, or vaginal hysterectomy (pathogens)?
pathogens: enterobacterales, anaerobes, GBS, enterococci
Tx: Cefazolin 2 g IV +/- metronidazole 500 mg IV x 1 dose WITHIN 60 MINUTES OF INCISION
if allergy: Clindamycin OR Vancomycin + Gentamicin OR FQ
OR metronidazole + (Gentamicin + FQ)
What is the recommended prophylaxis tx for SSI in C-sections (pathogens)?
pathogens: enterobacterales, anaerobes, GBS, enterococci
tx: cefazolin WITHIN 60 MIN OF INCISION
if allergy: Clindamycin + Gentamicin
What is the recommended prophylaxis tx for SSI in orthopedic join replacement (pathogens)?
Pathogens: S. aureus, S. epidermidis
Tx: Cefazolin 2 g IV, if MRSA suspected: add Vancomycin 15 mg/kg IV
if allergy to B-lactam: Vancomycin OR Clindamycin
What is the recommended prophylaxis tx for SSI in cardiothoracic/vascular surgery (pathogens)?
Pathogens: S. aureus, S. epidermidis, Enterobacterales
Tx: Cefazolin 2 g OR Cefuroxime 1.5 g IV
if MRSA suspected: add Vancomycin 15 mg/kg IV
if allergy to B-lactam: Vancomycin (possibly Clindamycin)
What is the recommended prophylaxis tx for SSI in colorectal surgery (pathogens)?
Pathogens: enterobacterales, anaerobes
Tx: mechanical bowel prep with Neomycin 1 g PO + Metronidazole 1 g PO (1300 h, 1500 h, 2000 h before surgery) THEN Cefazolin 2 g IV + metronidazole 500 mg IV
if allergy to B-lactam: same mechanical prep then Clindamycin + (Gentamicin + FQ) OR Metronidazole + (Gentamicin + FQ)
What is the recommended prophylaxis tx for SSI in appendectomy (pathogens)?
Pathogens: non-perforated
Tx: Cefazolin 2 g IV + metronidazole 500 mg IV
if allergy to B-lactam: Clindamycin + (Gentamicin OR FQ) OR Metronidazole + (Gentamicin OR FQ)
