Surgical Antibiotic Prophylaxis Flashcards
What is Surgical Antibiotic Prophylaxis (SAP)?
Administration of antimicrobials just prior to clean and clean-contaminated surgeries to prevent post-operative surgical site infections (SSI)
SSI is defined as:
- Infections occuring within 30days after after surgical operation
- Infections occuring within 1 year if an implant was left in place and affecting the incision or deep tissue at the operation site
What are the 3 levels of SSI?
- Superficial (skin and sc)
- Deep incisional (fascia and muscle)
- Involving organs or body spaces
What are some patient related risk factors for SSI?
- Age
- Smoking
- Coexistent infections at remote body site
- Colonization (MRSA)
- Recent surgical procedure*
- Underlying illness
- Obesity (>20% IBW)
- Nutritional status (malnourished)
- DM
- Length of pre-operative stay*
- (more likely to be colonized) - Altered immune response
What are some operation related risk factors for SSI?
- Duration of surgical scrub (disinfection time)
- Skin antisepsis
- Preoperative shaving - to clear pathogen
- Preoperative skin prep - to clear pathogen
- Duration of surgery (longer duration, higher risk of SSI)
- Antimicrobial prophylaxis
- Operating room ventilation
- Inadequate sterilization of instruments
- Foreign material in surgical site - biofilm?
- Surgical drains - biofilm?
- Surgical technique of surgeon
An ideal prophylactic antimicrobial regimen should be
- Effective against pathogen most likely to contaminate the surgical site (generally skin flora)
- Given at appropriate dose, that achieves highest tissue conc. upon skin incision
- Administered for shortest effective period to minimize ADR, minimize development of AMR, minimize cose
SAP is indicated for what type of surgery?
- Clean surgery
- Required if prosthesis or implant inserted
- NOT required if mucosa and cavity not traversed - Clean-contaminated surgery
- Always required as mucosa and cavity is penetrated under controlled conditions w/o unusual contamination
*SAP can be justified for any other procedure whereby pt has underlying medical condition (e.g., DM) associated with increased risk of SSI or if pt is immunocompromised
Is SAP indicated for contaminated surgery?
No. Contaminated surgery is defined as macroscopic soiling of operative field. (e.g., large bowel resection)
Antibiotic is used as TREATMENT rather than prophylaxis in contaminated surgeries
What spectrum of antibiotics are preferred for SAP?
Why?
Narrow-spectrum, able to cover expected pathogens for operative site (but may not cover 100%)
Because broad spectrum agents incr risk of AMR
Some agents (e.g., 3rd gen cephalosporins, fluoroquinolones, clindamycin) also incr risk of C. diff infections
*Also consider local resistance pattern
Antibiotic chosen for SAP should concentrate in high levels at the site __________
Prior to incision
In which group of pt is screening for MRSA colonization required?
Patient who will be undergoing high-risk surgeries (e.g., cardiac, orthopaedic, neurosurgery with implant)
=> Should be screened for MRSA colonization to decolonize accordingly
Which antibiotic should be considered for prophylaxis in pt with known MRSA colonization or recent MRSA infection?
Vancomycin
When should Cefazolin be used for SAP?
Cefazolin can be added to vancomycin for prophyalxis in MRSA colonized patients since vancomycin is less effective against MSSA
Patients with B-lactam allergies are at ___________ of SSI because ___________________
Increased risk/odds
Because they have to use 2nd line SAP
Patients with severe Penicillin allergy (anaphylaxis, urticaria, bronchospasm, angioedema, SJS, TEN) should NOT receive B-lactam for prophylaxis
Patients with uncomplicated non-IgE mediated allergic reaction to penicillin (e.g., maculopapular rash) can consider?
- Cephalosporins (discuss with patient and allergy team)
- Cefazolin (unique R1 side chain, no cross-reactivity expected)
