The most important factor to preventing infection in open fractures is time to antibiotics, less than 1 hour from time of injury is ideal.

Summary Chart:

*Can’t use metronidazole with intoxicated folks

• Levo 500mg IV q24h

• Metro 500mg IV q8h

• Ceftriaxone 2gIV q 24h

• Vanc 15mg/kg IV q12h

• Clinda 900mg IV q8h

• Zosyn 4.5g IV q8h

• Ancef 2g IV q8 (3g if >120kg)

Gustillo-Anderson Classification for Open Fractures:

• Type 1: Laceration <1cm in diameter

• Type 2: Laceration >1cm <10cm without signs of high energy (Extensive soft tissue injury despite intact skin)

• Type 3: >10cm soft injury (All High Energy open fracture or those with gross contamination regardless of the size of the wound)

• Type 3 A: Adequate soft tissue for coverage of fracture

• Type 3 B: Inadequate soft tissue coverage, Flap required

• Type 3 C: Associated arterial injury requiring repair

• Open Fractures

• Always Start with Cefazolin (Ancef)

• 2-grams IV immediately and then every 8 hours 

• Infection rate after Ancef prophylaxis is markedly lower than compared with other antibiotics

• If allergic to Ancef, give Clindamycin or Vancomycin (if high prevalence of MRSA) 

• Gram-negative coverage for type 3 open fractures

• Aminoglycosides

• Once daily dose Gentamicin 5mg/kg/d is preferred to decrease risk of acute kidney injury and ototoxicity

• Fluoroquinolone if concern for kidney problems

• Avoid if on warfarin (can decrease warfarin liver metabolism

• Inhibits endochondral ossification (Don’t use in pediatric open fractures)

• May inhibit fracture healing in rats (not well defined in adults)

• Barnyard Type Injuries (Soil or Feces = Clostridium Species)

• High Dose Penicillins for anaerobic coverage

• Piperacillin-Tazobactam (Zosyn)

• Noninferiority to use as monotherapy instead of Ancef and Gentamicin in type 3 open fractures

• Avoids adverse reactions to aminoglycosides (kidney injury and ototoxicity)

• Penicillin allergy

• Author example of other antibiotic options

• Type 1 and 2

• Ancef 2g IV immediately then Q8 hours 

• Penicillin allergic

• Clindamycin 900mg IV immediately and q8 hours

• Type 3 injuries

• Ceftriaxone 2g IV immediately for 1 dose

• Vancomycin 1g IV immediately and q12 hours

• Penicillin allergy

• Aztreonam 2g IV immediately and q8 hours

• Vancomycin 1g IV immediately and q12 hours

•  Duration of Therapy

• Type 1 and 2 open fractures

• Discontinue antibiotics 24 hours after wound closure in type 1 and type 2 injuries regardless of duration of therapy between presentation and surgery

• Type 3 open fractures

• Antibiotics for 72 hours after injury or 24 hours after soft-tissue coverage

References:

https://www.ncbi.nlm.nih.gov/pubmed/31851021

https://www.orthobullets.com/trauma/1004/open-fractures-management

https://www.nebraskamed.com/sites/default/files/documents/for-providers/asp/Antibiotic-Prophylaxis-in-Open-Fractures-Guideline.pdf