What antibiotics (ATB) are used to treat burn infections?

Antibiotic Treatment for Burn Infections

For established burn wound infections with systemic signs, initiate empiric broad-spectrum IV antibiotics immediately that cover both Gram-positive organisms (including MRSA based on local epidemiology) and Gram-negative pathogens including Pseudomonas aeruginosa, using high doses with continuous infusion when possible, guided by cultures and therapeutic drug monitoring. 1

Key Principle: Prophylaxis vs. Treatment

Do NOT use sustained systemic antibiotic prophylaxis in burn patients without active infection. 1 The Surviving Sepsis Campaign explicitly recommends against sustained antimicrobial prophylaxis in severe inflammatory states of noninfectious origin, including burn injury. 1

However, systemic antibiotic prophylaxis administered in the first 4-14 days significantly reduced all-cause mortality by nearly half in severe burns, though topical antibiotic prophylaxis showed no beneficial effects. 1

When to Initiate Antibiotics

Antibiotics should be administered for:

• Patients with systemic signs of infection (fever, hemodynamic instability, altered mental status) 1
• Severe cellulitis spreading from burn wound 1
• Patients with compromised immune status or severe comorbidities 1
• Severe and deep wounds with clinical evidence of infection 1

If sepsis or septic shock is present, administer IV antimicrobials within one hour of recognition. 1

Microbiology of Burn Infections

Burn wound infections are typically polymicrobial: 1

• Early colonization (first 48 hours): Gram-positive bacteria from endogenous skin flora (S. aureus, including MRSA) 1
• Later colonization (within one week): Gram-negative bacteria predominate, particularly Pseudomonas aeruginosa and Acinetobacter species 1, 2
• Common pathogens include: S. aureus (46%), S. epidermidis, E. coli, Proteus spp., Klebsiella pneumoniae, and P. aeruginosa 3
• Fungal infections: Candida spp., Aspergillus spp., and Fusarium spp. may occur in severe cases 2

Empiric Antibiotic Regimens

First-Line Broad-Spectrum Coverage

Empiric therapy must cover all likely pathogens including Gram-positive, Gram-negative, and potentially fungal organisms. 1

Recommended empiric regimens:

• Vancomycin PLUS piperacillin-tazobactam - This combination provides comprehensive coverage of MRSA and multidrug-resistant Gram-negative organisms 2
• Vancomycin PLUS ceftazidime or cefepime - Alternative for Pseudomonas coverage 4
• Vancomycin PLUS meropenem - For critically ill patients or suspected multidrug-resistant organisms 2, 4

MRSA Coverage

Include empiric MRSA coverage based on: 1

• Local epidemiology (>20% MRSA in invasive hospital isolates)
• High community MRSA circulation
• Previous MRSA colonization or infection

Vancomycin and clindamycin are the most important reserve antibiotics for MRSA. 2 Oxazolidinones and streptogramins have shown high effectiveness against Gram-positive infections. 2

Multidrug-Resistant Gram-Negative Coverage

For infections with multidrug-resistant Pseudomonas or Acinetobacter, colistin has re-emerged as highly effective. 2 Vancomycin plus colistin should be used for at least three days when these organisms are documented. 2

Critical Dosing Considerations

Burn patients require HIGH DOSES and preferably CONTINUOUS INFUSION of beta-lactam antibiotics due to altered pharmacokinetics. 4, 5

Pharmacokinetic Alterations in Burns

Burn injury causes profound changes: 4, 6, 5

• Augmented renal clearance (creatinine clearance ≥130 mL/min) during hypermetabolic phase
• Increased volume of distribution
• Enhanced drug elimination
• Wide inter- and intra-individual variability

Specific Dosing Recommendations

Use therapeutic drug monitoring whenever possible to optimize pharmacokinetic-pharmacodynamic target achievement. 1, 4, 5 Standard package insert doses often fail to achieve adequate PK-PD parameters in burn patients. 5

Optimize dosing based on accepted pharmacokinetic/pharmacodynamic principles. 1

For broad-spectrum beta-lactams (meropenem, piperacillin-tazobactam, ceftazidime, cefepime, imipenem-cilastatin, aztreonam): 4

• Use high doses
• Administer via continuous infusion when feasible
• Monitor drug concentrations to guide therapy

Duration and De-escalation

Reassess antimicrobial regimen daily for potential de-escalation. 1

Narrow therapy once pathogen identification and sensitivities are established and/or adequate clinical improvement is noted. 1

Typical duration: 7-10 days for most serious infections. 1 Longer courses may be appropriate for: 1

• Slow clinical response
• Undrainable foci of infection
• S. aureus bacteremia
• Fungal infections
• Immunologic deficiencies

Essential Adjunctive Measures

Surgical source control is CRUCIAL and takes priority: 1

• Early excision of eschar substantially decreases invasive burn wound infection incidence 1
• Debridement of necrotic tissue is mandatory 1
• Removal of contaminated material 1

Obtain bacterial cultures to guide antibiotic selection, especially given high rates of drug resistance. 1

Common Pitfalls

• Avoid silver sulfadiazine - Associated with increased burn wound infection rates and longer hospital stays compared to dressings/skin substitutes 1
• Do not use routine prophylaxis in non-infected burns - increases MRSA rates without reducing infection 1
• Do not underdose - Standard doses are inadequate due to altered pharmacokinetics 4, 5
• Do not delay source control - Antibiotics alone are insufficient without surgical debridement 1