Episode 204: Necrotizing Fasciitis

We discuss the recognition and treatment of necrotizing fasciitis.

Hosts:

Aurnee Rahman, MD

Brian Gilberti, MD

https://media.blubrry.com/coreem/content.blubrry.com/coreem/Necrotizing_Fasciitis.mp3

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Tags: Critical Care, General Surgery

Show Notes

Table of Contents

0:00 – Introduction

0:41 – Overview

1:10 – Types of Necrotizing Fasciitis

2:21 – Pathophysiology & Risk Factors

3:16 – Clinical Presentation

4:06 – Diagnosis

5:37 – Treatment

7:09 – Prognosis and Recovery

7:37 – Take Home points

Introduction

Necrotizing soft tissue infections can be easily missed in routine cases of soft tissue infection.

High mortality and morbidity underscore the need for vigilance.

Definition

A rapidly progressive, life-threatening infection of the deep soft tissues.

Involves fascia and subcutaneous fat, causing fulminant tissue destruction.

High mortality often due to delayed recognition and treatment.

Types of Necrotizing Fasciitis

Type I (Polymicrobial)

Involves aerobic and anaerobic organisms (e.g., Bacteroides, Clostridium, Peptostreptococcus).

Common in immunocompromised patients or those with comorbidities (e.g., diabetes, peripheral vascular disease).

Type II (Monomicrobial)

Often caused by Group A Streptococcus (Strep pyogenes) or Staphylococcus aureus.

Can occur in otherwise healthy individuals.

Vibrio vulnificus (associated with water exposure) is another example.

Fournier’s Gangrene (Subset)

Specific to perineal, genital, and perianal regions.

Common in diabetic patients.

Higher mortality, especially in females.

Pathophysiology

Spread Along Fascia

Poor blood supply in fascial planes allows infection to advance rapidly.

Tissue ischemia worsened by vascular thrombosis → rapid necrosis.

High-Risk Patients

Diabetes with vascular compromise.

Recent surgeries or trauma (introducing bacteria into deep tissue).

Immunosuppression (e.g., cirrhosis, malignancy, or immunosuppressive meds).

NSAID use may mask symptoms, delaying diagnosis.

Clinical Presentation

Early Signs & Symptoms

Severe Pain out of proportion to exam findings.

Erythema (often with indistinct borders).

Fever, Malaise (systemic signs of infection).

Rapid progression with possible color changes (red → purple).

Bullae Formation (fluid-filled blisters) and skin necrosis/gangrene.

Crepitus in polymicrobial cases (gas production in tissue).

Late-Stage Signs

Systemic toxicity: hypotension, multi-organ failure if untreated.

Diagnosis

Clinical Suspicion Is Key

Pain out of proportion, rapid progression, systemic signs.

The “finger test” (small incision to explore fascial planes).

Surgical Consultation

Early surgical exploration is often the definitive diagnostic step.

Lab Tests

LRINEC Score (CRP, WBC, Hemoglobin, Sodium, Creatinine, Glucose) to stratify risk.

Not definitive but can guide suspicion.

Imaging

CT scan may reveal gas in tissues, fascial edema, or muscle involvement.

Must not delay surgical intervention if clinical suspicion is high.

Treatment Principles

Immediate & Aggressive Surgical Debridement

Often multiple surgical procedures are required as necrosis progresses.

Debridement back to healthy tissue margins.

Empiric Broad-Spectrum Antibiotics

Cover gram-positive (including MRSA), gram-negative, and anaerobes.

Examples include:

Vancomycin or Linezolid (for MRSA).

Piperacillin-tazobactam or Carbapenems (for gram-negative & anaerobes).

Clindamycin (to inhibit bacterial toxin production).

Adjust based on culture results later.

Adjunct Therapies

Hyperbaric Oxygen Therapy (if available) for resistant cases.

Evidence is mixed; not universally accessible.

Supportive Care

Intensive monitoring, often in an ICU setting.

Fluid resuscitation & vasopressors for septic shock.

Prognosis & Disposition

High Mortality Rate

Influenced by infection site, patient’s baseline health, and speed of intervention.

Importance of Rapid Intervention

Early recognition, aggressive surgery,