What is the vancomycin (Vanc) trough goal for preventing perioperative infections?

Vancomycin Trough Goals for Perioperative Infection Prevention

For perioperative infection prophylaxis, vancomycin trough concentrations of at least 10 mg/L are appropriate when used with local vancomycin therapy or rifampin, while trough concentrations of 15-20 mg/L are recommended for MRSA prophylaxis without these adjuncts. 1

Dosing Recommendations

• Vancomycin should be dosed at 15 mg/kg IV for perioperative prophylaxis, rather than using a fixed 1g dose, which frequently results in underdosing 2, 3
• Prophylactic vancomycin should be infused within 120 minutes before surgical incision to ensure adequate tissue concentrations 1
• For patients known to be colonized with MRSA, vancomycin is a reasonable choice for perioperative prophylaxis, though it should be considered in combination with cefazolin as vancomycin alone is less effective against methicillin-susceptible S. aureus (MSSA) 1

Trough Concentration Targets

• For MRSA prosthetic joint infections (PJI) treated without rifampin or local vancomycin spacers, trough concentrations of 15-20 mg/L are recommended 1
• When rifampin or vancomycin-impregnated spacers are utilized, trough concentrations of at least 10 mg/L may be appropriate 1
• Weight-based dosing (15 mg/kg) is crucial for achieving target trough concentrations, as fixed 1g dosing results in 64-69% of patients being underdosed 2, 3

Special Considerations

• Target troughs should be chosen with guidance from infectious disease specialists based on the pathogen, its in vitro susceptibility, and use of adjunctive therapies 1
• For patients with oxacillin-resistant, coagulase-negative staphylococci, it remains unclear if the higher trough concentrations (15-20 mg/L) are necessary 1
• Monitoring for efficacy and toxicity is advisable, especially with higher dosing regimens 1, 4

Pitfalls and Caveats

• Fixed 1g dosing of vancomycin results in subtherapeutic levels in most patients, potentially increasing the risk of surgical site infections 2, 3
• Studies have shown that patients receiving vancomycin prophylaxis have a higher rate of periprosthetic joint infection (2%) compared to those receiving cefazolin (1%) when not properly dosed 2
• Trough-only monitoring may underestimate the true AUC by approximately 23%, potentially leading to unnecessary dose increases and toxicity risk 5
• For serious infections, an AUC:MIC ratio ≥400 is the most useful pharmacodynamic parameter to predict vancomycin effectiveness 4, 5
• Extending perioperative antimicrobials beyond 24 hours can lead to hypersensitivity reactions, renal failure, antimicrobial resistance, and C. difficile-associated diarrhea 1

Algorithm for Perioperative Vancomycin Prophylaxis

1. Determine if patient has MRSA colonization or penicillin allergy requiring vancomycin 1
2. Calculate weight-based dose at 15 mg/kg rather than using fixed 1g dose 2, 3
3. Administer vancomycin 120 minutes before surgical incision 1
4. Consider combination with cefazolin if MRSA risk and no beta-lactam allergy 1
5. For patients with implants or prosthetics, aim for trough of 15-20 mg/L if used alone, or at least 10 mg/L if used with local vancomycin therapy 1
6. Discontinue prophylactic vancomycin within 24 hours after clean or clean-contaminated procedures 1