What is the recommended treatment for deep tissue infections?

Treatment of Deep Tissue Infections

The recommended treatment for deep tissue infections includes prompt surgical debridement combined with broad-spectrum empiric antibiotic therapy, with specific regimens tailored based on infection severity, suspected pathogens, and patient factors. 1, 2

Classification and Initial Assessment

• Deep tissue infections should be classified as either necrotizing or non-necrotizing, as this distinction guides management decisions and urgency of intervention 1
• Severity assessment should categorize patients into mild/moderate or high risk of poor outcome to guide treatment intensity 1
• Evaluate for signs suggesting necrotizing infection requiring immediate surgical intervention, including pain disproportionate to physical findings, violaceous bullae, skin sloughing, rapid progression, and gas in tissue 2

Surgical Management

• Prompt surgical consultation is essential for patients with aggressive infections, signs of systemic toxicity, or suspicion of necrotizing fasciitis or gas gangrene 1
• All necrotizing soft tissue infections (NSTIs) require surgical debridement as the primary intervention - delaying surgery increases mortality 1
• For abscesses, incision and drainage is the primary treatment, with antibiotics as adjunctive therapy 1
• For surgical site infections, opening the incision, evacuating infected material, and performing wound cultures are the most important initial steps 1

Antibiotic Therapy

For Non-Necrotizing Infections:

• For mild-moderate infections without systemic signs, targeted antibiotic therapy based on likely pathogens is appropriate 2
• For surgical site infections following clean procedures, consider:
  • Oxacillin/nafcillin 2g IV every 6h, cefazolin 0.5-1g IV every 8h, or vancomycin 15mg/kg IV every 12h (if MRSA risk) 1

For Necrotizing Infections:

• Empiric antibiotic treatment should be broad-spectrum as these infections can be polymicrobial or monomicrobial 1
• Recommended regimens include:
  • Single-drug options: Piperacillin-tazobactam 3.375g every 6h or 4.5g every 8h IV, carbapenem (imipenem, meropenem, or ertapenem), or ampicillin-sulbactam 1, 3
  • Combination regimens: Ceftriaxone 1g every 24h plus metronidazole 500mg every 8h IV, or fluoroquinolone plus metronidazole 1
  • Add MRSA coverage with vancomycin 15mg/kg IV every 12h, linezolid 600mg every 12h, or daptomycin 4-6mg/kg daily when indicated 1
• For documented group A streptococcal necrotizing fasciitis, penicillin plus clindamycin is recommended 1

For Multidrug-Resistant Organisms:

• For infections with carbapenem-resistant gram-negative bacteria, consider colistin (loading dose 9 MU followed by 4.5 MU twice daily) with close monitoring of renal function 1
• Newer agents like ceftazidime-avibactam, ceftolozane-tazobactam, and imipenem-cilastatin-relebactam may be considered for difficult-to-treat Pseudomonas infections 1

Special Considerations

• For diabetic patients with lower extremity infections, evaluate for underlying osteomyelitis which may require longer treatment duration 2, 4
• In injection drug users, consider community-based models of IV antibiotic therapy to improve treatment completion rates 5
• For infected burns, obtain cultures before starting antibiotics and consider coverage for both gram-positive and gram-negative organisms 6
• Duration of therapy should be guided by clinical response, typically 7-14 days for soft tissue infections without osteomyelitis 2, 6

Monitoring and Follow-up

• Reassess within 24-48 hours to evaluate response to therapy 2
• Consider repeat surgical debridement if clinical improvement is not observed 2
• Adjust antibiotics based on culture results and clinical response 2, 7
• For patients with severe infections who improve clinically, transition from IV to oral therapy when possible 1

Common Pitfalls to Avoid

• Delaying surgical consultation for potentially necrotizing infections 1
• Failing to obtain appropriate cultures before initiating antibiotics 2
• Inadequate debridement of necrotic tissue 1
• Overreliance on antibiotics alone for infections with necrotic tissue 4
• Failing to monitor for antibiotic toxicity, particularly with agents like colistin 1