What antibiotics are recommended for mastoid fractures?

Antibiotic Management for Mastoid Fractures

Primary Recommendation

For mastoid fractures (open/compound skull fractures), initiate cefazolin 2g IV immediately upon presentation and continue for 3 days for less severe fractures or 5 days for severely contaminated fractures. 1

Initial Antibiotic Selection

• First-line agent: Cefazolin 2g IV is the recommended first-generation cephalosporin for most open skull fractures, including mastoid fractures 1
• For severely contaminated mastoid fractures, add an aminoglycoside (such as gentamicin) to enhance gram-negative coverage 1
• Beta-lactam allergy alternatives: Use clindamycin 900mg IV or vancomycin 30mg/kg over 120 minutes 2

Timing of Administration

• Antibiotics must be started immediately upon presentation - delaying beyond 3 hours post-injury significantly increases infection risk 1
• Mastoid fractures are contaminated wounds requiring therapeutic antibiotics, not just prophylaxis 1
• If surgical intervention is planned, ensure antibiotic infusion is completed within 60 minutes before incision 2

Duration of Therapy

• Continue antibiotics for 3 days for less severe open fractures 1
• Continue for 5 days for severe open fractures with significant contamination 1
• Continuing antibiotics beyond these recommended durations without documented infection increases antibiotic resistance risk 1

Adjunctive Measures

• Antibiotic therapy is an adjunct to surgical debridement, not a replacement - adequate surgical management remains essential 1
• Consider local antibiotic delivery systems (antibiotic-impregnated beads) as adjuncts in severe cases 1
• Re-dosing of cefazolin is required every 4 hours for prolonged procedures 1

Critical Pitfalls to Avoid

• Never delay antibiotic administration - the critical window is within 3 hours of injury 1
• Do not rely solely on antibiotics without adequate surgical debridement 1
• Avoid extending antibiotics beyond 3-5 days without documented infection to prevent resistance 1
• Do not confuse mastoid fractures with elective mastoid surgery (which showed no benefit from prophylactic antibiotics in one older study) 3 - traumatic fractures require immediate therapeutic antibiotics