What's the best course of action for a patient with a severe infected thigh hematoma (hematoma infection) that's not responding to antibiotics and where interventional radiology (IR) drainage was unsuccessful?

Management of Infected Thigh Hematoma Failing Conservative Treatment

Proceed urgently to open surgical drainage and debridement, as this represents a failed minimally invasive approach requiring definitive surgical intervention to prevent progression to necrotizing infection or sepsis.

Immediate Assessment and Stabilization

Clinical evaluation priorities:

• Assess for systemic sepsis indicators: tachycardia, hypotension, altered mental status, elevated lactate, and procalcitonin 1
• Examine for signs of necrotizing soft tissue infection: crepitus, skin necrosis, rapid progression, severe pain disproportionate to exam 1
• Obtain urgent laboratory studies: complete blood count, coagulation parameters, blood cultures, inflammatory markers (CRP, procalcitonin) 1
• Ensure hemodynamic stability with fluid resuscitation and blood transfusion if hemoglobin <7 g/dL 1

Imaging reassessment:

• Obtain repeat CT or MRI to evaluate collection size, loculations, and extent of soft tissue involvement 1
• Look for undrained pockets, septations, or fistulous communications that explain IR drainage failure 1

Antibiotic Management

Broaden antibiotic coverage immediately:

• Initiate broad-spectrum empiric therapy targeting aerobic gram-positive cocci (including MRSA), gram-negative bacilli, and anaerobes 1
• Consider vancomycin plus piperacillin-tazobactam or a carbapenem as initial regimen 1
• Add antifungal coverage if patient is immunocompromised or has prolonged antibiotic exposure 1
• Obtain deep tissue cultures (not swabs) during surgical intervention to guide definitive therapy 1

Critical caveat: Antibiotics alone are insufficient without adequate source control through drainage 1. Continuing antibiotics without addressing the undrained collection will lead to treatment failure and potential septic complications.

Definitive Surgical Intervention

Open surgical drainage is indicated when:

• Percutaneous drainage has failed to adequately drain the collection 1
• Multiple loculations or septations prevent complete percutaneous evacuation 1
• Underlying vascular injury or foreign body requires surgical exploration 2
• Signs of necrotizing infection are present 1

Surgical approach:

• Perform extensive incision and drainage with exploration of all pockets 1
• Obtain deep tissue specimens for aerobic and anaerobic culture and histopathology 1
• Debride all necrotic and infected tissue aggressively 1
• Place surgical drains for ongoing drainage postoperatively 1
• Consider negative pressure wound therapy for large defects 1

Laparoscopic drainage may be considered if the collection is accessible and the patient is stable, though open surgery provides superior visualization and ability to address complex anatomy 1.

Why IR Drainage May Have Failed

Common reasons for percutaneous drainage failure:

• Collection too viscous or organized for catheter drainage 1
• Multiple septations or loculations not accessible via single catheter 1
• Ongoing source (fistula, vascular injury, foreign body) maintaining infection 1, 2
• Inadequate catheter size or positioning 1
• Catheter malfunction or premature removal 1

The ACR guidelines note that approximately one-third of abscesses may not be amenable to percutaneous drainage 1, and your case appears to fall into this category.

Timing and Urgency

Do not delay surgical intervention:

• Persistent infection despite antibiotics and drainage indicates treatment failure requiring escalation 1
• Risk of progression to necrotizing fasciitis, septic shock, or death increases with delay 1
• Mortality from undrained abscesses ranges from 45-100% 3

Proceed to surgery within 24 hours of recognizing treatment failure, as temporizing with continued antibiotics and inadequate drainage significantly increases morbidity and mortality 1, 3.

Post-Surgical Management

Continued antibiotic therapy:

• Tailor antibiotics based on intraoperative culture results 1
• Continue parenteral antibiotics until clinical improvement (resolution of fever, normalization of inflammatory markers, wound improvement) 1
• Duration typically 2-3 weeks for moderate to severe soft tissue infections 1

Wound management:

• Monitor surgical drains for output and character 1
• Remove drains when output <10-20 cc daily and no residual collection on imaging 1
• Serial imaging may be needed to confirm resolution 1

Follow-up:

• Close monitoring for recurrence or complications 1
• Repeat imaging if clinical deterioration occurs 1

Critical Pitfalls to Avoid

• Do not continue failed conservative management: Persistent infection despite antibiotics and IR drainage mandates surgical intervention 1, 3
• Do not wait for fever to diagnose worsening infection: Tachycardia, increased pain, and elevated inflammatory markers indicate progression even without fever 1, 4
• Do not rely on swab cultures: Deep tissue specimens obtained surgically provide accurate microbiologic diagnosis 1
• Do not remove drains prematurely: Ensure clinical and radiographic resolution before drain removal 1