Oral Board Case: Necrotizing Soft Tissue Infection

What is your leading diagnosis and what features support it?

Expected answer

Necrotizing soft tissue infection (necrotizing fasciitis). Supporting features are pain out of proportion to exam, rapid progression, crepitus, skin necrosis, systemic toxicity/sepsis, and the high-risk host (diabetes, obesity). This is a surgical emergency, not simple cellulitis.

How do you distinguish NSTI from severe cellulitis or a simple abscess?

Expected answer

NSTI is suggested by pain out of proportion, rapid progression despite antibiotics, systemic toxicity, tense edema beyond the area of erythema, bullae, ecchymosis, crepitus, cutaneous anesthesia, and skin necrosis. Cellulitis lacks crepitus, necrosis, and disproportionate pain. The diagnosis is ultimately clinical and surgical — when in doubt, explore.

What initial workup and labs do you order, and how does the LRINEC score help?

Expected answer

CBC, complete metabolic panel, CRP, lactate, blood cultures, and coagulation studies. The LRINEC score uses WBC, hemoglobin, CRP, sodium, glucose, and creatinine; a score ≥6 indicates high likelihood of NSTI. It is an adjunct only — a low score does NOT rule out NSTI and must never delay operative exploration in a convincing clinical picture.

This patient is septic. What is your resuscitation and antibiotic plan?

Expected answer

Aggressive IV crystalloid resuscitation, monitor end-organ perfusion (urine output, lactate, mental status), correct hyperglycemia and electrolytes, and admit to a monitored/ICU setting. Start broad-spectrum empiric antibiotics covering gram-positives, gram-negatives, and anaerobes including clostridia — e.g., vancomycin (or linezolid) plus a broad gram-negative agent (piperacillin-tazobactam or carbapenem) plus clindamycin for antitoxin/anti-toxin effect. The source regimen lists penicillin G, vancomycin, gentamicin, and clindamycin.

Resuscitation is underway. Do you wait for imaging before going to the OR?

Expected answer

No. With crepitus, necrosis, and septic physiology the diagnosis is clinical and operative exploration/debridement is the definitive intervention. Imaging (CT showing fascial gas/edema) may support equivocal cases but must never delay the OR in a clear or unstable presentation. Nonoperative management approaches 100% mortality.

Describe your operative goals and how you judge adequacy of debridement.

Expected answer

Wide, aggressive debridement of all necrotic skin, subcutaneous tissue, and fascia, extending to healthy, bleeding, viable tissue at all margins. Look for gray, dishwater fluid, easy finger dissection along fascial planes, lack of bleeding, and thrombosed vessels. Send tissue/fluid for Gram stain and culture. Do not be limited by cosmetic concerns; leave the wound open and packed.

What is your plan after the first operation?

Expected answer

ICU-level critical care with ongoing resuscitation, broad-spectrum antibiotics (narrowed when cultures return), and management of comorbidities (glycemic control). Planned return to the OR within 24 hours for re-evaluation and further debridement; most patients require 3–4 serial debridements until the infection is controlled.

You have a lower-suspicion case where exploration is uncertain. How can you confirm the diagnosis?

Expected answer

Perform a bedside incision and probe. If you can easily slide a finger along the fascial plane with loss of normal tissue resistance, find necrotic tissue, or encounter 'dishwater' gray fluid, the diagnosis is confirmed and the patient goes to the OR for formal debridement. If exploration is negative, treat with antibiotics, IV fluids, and close observation.

What does long-term recovery and follow-up involve?

Expected answer

A multidisciplinary approach: ongoing wound management (negative-pressure dressings), reconstruction with skin grafting or flap coverage of large defects, physical rehabilitation, nutritional support, and tight management of diabetes and other comorbidities.