Ch. 10 Infections and Antimicrobials Flashcards
Six key risk factors identified in risk of surgical wound infections
- duration of surgery
- duration of anesthesia
- surgical site preparation
- method of wound closure
- antimicrobial prophylaxis
- comorbidities
Criteria for a superficial surgical site infection
- within 30 days of operative procedure
- involves skin and/or SQ tissues of the incision
- one or more of the following: purulent drainage, bacteria aseptically cultured from the incision, diagnosis of a superficial incisional infection by the surgeon, heat/redness/painr OR localized swelling AND incision reopened by surgeon unless culture negative
criteria for a deep surgical site infection
- within 30 days (90 for some procedures)
- deep soft tissues of the incision (fascia or muscle) affected
- one or more of: purulent drainage, spontaneous dehiscence of deeper incision OR incision is deliberately opened when patient has fever/localized pain OR tenderness UNLESS culture is negative
criteria for organ/space surgical site infection
- within 30 days (90 for some procedures)
- any area other than the incision (skin, fascia, muscle) that was encountered during surgery
- one or more of: purulent drainage, bacteria, abscess or other evidence of infection on exam/reoperation/histo/imaging
How does duration of surgery increase risk of infection
greater ability of bacteria to be exposed to and adhere within the surgical wounds
also may have more tissue desiccation
How does duration of anesthesia increase risk of surgical site infection
no one true thing but anesthesia can lead to decreased body temp and impact the immune system
how does surgical site preparation influence risk of surgical site infection
such as traumatic clipping, excessive scrubbing, clipping/shaving well in advance of surgery… might be skin trauma?
how does the method of wound closure relate to risk of increased surgical site infection
not clearly demonstrated
skin staples were associated with an increased risk following stifle surgery in one retrospective but in another prospective, no difference between skin sutures and intradermal
Name the anticipated bacteria and prophylactic antimicrobial for: skin and reconstructive surgery
staph –> cefazolin
Name the anticipated bacteria and prophylactic antimicrobial for: elective orthopedic surgery
staph –> cefazolin
Name the anticipated bacteria and prophylactic antimicrobial for: head and neck surgery
staph, strep, anaerobes –> clindamycin or cefazolin
Name the anticipated bacteria and prophylactic antimicrobial for: thoracic and non GI abdominal surgery
staph –> cefazolin
Name the anticipated bacteria and prophylactic antimicrobial for: open fractures
staph, strep, anaerobes –> cefazolin or clindamycin, +/- aminoglycoside or flouroquinolone
Name the anticipated bacteria and prophylactic antimicrobial for: Upper GI surgery
gram positive cocci, enteric gram negative bacilli –> cefazolin
Name the anticipated bacteria and prophylactic antimicrobial for: lower GI surgery
enterococci, gram negative bacilli, anaerobes –> cefoxitin
Name the anticipated bacteria and prophylactic antimicrobial for: hepatobiliary surgery
Clostridium, gram negative bacilli, anaerobes –> cefoxitin
Name the anticipated bacteria and prophylactic antimicrobial for: urogenital surgery
streptococcus, staph, e coli, anaerobes –> cefazolin or ampicillin
What are the three strategies of the Surgical Care Improvement Project to administer prophylactic antibiotics
- base antimicrobial selection on the pathogens expected to be present
- ensure appropriate timing of the antimicrobial administration to ensure peak serum drug concentration at the time of first incision
- discontinue the use of prophylactic antimicrobials within 24 hours post op
What is the class and half life of cefazolin?
first generation cephalosporin
47 min –> that is why we redose every 90 min in surgery, we redose every two half lives
What is the class and half life of ampicillin
penicillin
48 min
What is the class and halflife of clindamycin
lincosamide
124-195 min (2-3 hours?)
what is the class and half life of cefoxitin
second generation cephalosporin
40-60 min
Description of a clean wound
non traumatic, uninfected
no break in aspetic technique
no inflammation encountered
primarily closed, elective, no drains
description of a clean contaminated wound
controlled entry into a hollow viscus organ, minor break in aseptic technique
description of a contaminated wound
open, fresh traumatic wound, incision into a site with acute non purulent inflammation, major break in aseptic technique
description of a dirty wound
pus encountered, perforated viscus organ, traumatic wound with devitalized tissues/foreign material/fecal contamination/older than 4 hours, acute bacterial infection
