1. Necrotizing Fasciitis: Current Concepts and review of the Literature
Trauma Conference
4/28/2010
Emmanouil Palaios MD

2. Necrotizing Fasciitis: Current Concepts and Review of the Literature
High mortality: %
Mortality directly proportional to time of intervention.
Purpose: review the microbiology, pathophysiology, diagnosis, and treatment of NSTI.
Data from retrospective and nonblinded studies.

3. Necrotizing Fasciitis: Current Concepts and review of the Literature
“Many were attacked by erysipelas all over the body when the exciting cause was a trivial accident…flesh, sinews, and bones fell away in large quantities…there were many deaths.”
Hippocrates ( 500 BC)

4. Necrotizing Fasciitis: Current Concepts and review of the Literature
As early as 1871 Dr. Joseph Jones: 2642 cases/ mortality 46%
(1883): Dr. Jean Alfred Fournier: NSTI of perineum in 5 male patients: Fournier’ s gangrene
(1951) Dr. Wilson : Necrotizing Fasciitis
Necrotizing Soft Tissue Infection
First reported case back in (1871 Dr. Joseph Jones): 2642 cases with mortality 46%

5. Incidence
Rare disease
Incidence: 1000 cases/year, 0.04 cases/1000 person-years (U.S.A)
Increased incidence
Prevalence: one or two cases/career for average practitioner.

6. Classification Factor
Comment
Anatomic location
Fournier’s gangrene perineum/scrotum
Depth of Infection (correlates with mortality)
Necrotizing adipositis (most common), fasciitis, myositis.
Microbial cause
Type I: polymicrobial (most common, 55-75%)
Type II: Monomicrobial: (staph, strep, clostridia).
Type III: Vibrio vulnificus

7. Microbiology/ Risk Factors Type I
Most common ( 55-75%).
Polymicrobial (GPC, GNR, Anaerobes).
C. Perfingens rare cause of NSTI.
Perineum- trunk.
Immunocompromised patients (DM, PVD).
IV drug use.
No inciting event for 20 to 50 % of patients.

8. Microbiology/ Risk Factors Type I
Immunocompromised patients
Obesity
Chronic Renal Failure
HIV
Alcohol abuse
Abscess
IV drugs
Trauma (blunt/penetrating)
Insect bites
Surgical incisions
Indwelling catheters
Chicken pox
Perforation of GI tract (clostridium septicum)

9. Microbiology/ Risk Factors Type II
Group A Streptococcus (pyogenes): can survive in macrophage.
Staphylococcus Aureus
Association with Toxic Shock Syndrome.
MRSA soft tissue infection cultured in up to 40% necrotic wounds ( IV drug abusers)
Healthy, young, immunocompetent hosts.
Location: extremities .
Trauma or operation.

10. Microbiology/ Risk Factors Type III
Least common type
Vibrio vulnificus
Skin break
Warm sea water
Coastal communities
Risk factor: chronic HBV
Fulminant course

11. Pathophysiology Invasion SC tissues ( trauma, perforated viscus)
Production of toxins
Tissue ischemia: thrombosis perforating skin vessels from local hypercoagulable state prevents adequate delivery of ABXS.
Liquefactive necrosis
Systemic illness.
Extent of infection larger than that suggested by skin findings.
Infection spread 1 inch/hour with little overlying skin change

12. Medical illustration of advanced necrotizing fasciitis with necrosis of skin, vascular thrombosis and involvement of underlying muscle.

13. Progression of NSTI

14. Diagnosis Finding Percent of patients Erythema 66-100 73-95 Swelling
Pain / tenderness beyond erythema
73-95
Swelling
75-92
Crepitus/skin necrosis
0-31
Induration
12-45
Bullae
23-45
Fluctuance 11
Fever
32-53
Hypotension
11-18

15. Differential Diagnosis
Disorder
Characteristic
Cellulitis/adipositis
Erythematous edematous tissue with normal subc. fat and fascia
Myonecrosis
Noninfectious inflammation/ necrosis of muscle only
Noninfectious fasciitis
Chronic disorder, Dx. biopsy,
Tx. Steroids
Phlegmasia cerulea dolens
Edema of entire affected extremity
Myxedema
Systemic manifestations of severe hypothyroidism

16. History and Physical
Trauma/skin break 48 hrs. before symptoms (10-40%)
Local erythema
Swelling with pain beyond the apparent confines of infection.
Normal skin appearance in early stages.
Crepitus or skin necrosis: % cases
Vibrio vulnificus: fulminant NSTI
Proper diagnosis as low as 14 % of cases.

17. History and Physical 89 patients: 5 year f/u.
Proper Dx of NSTI: 14 % only.
Dx of cellulitis/abscess: 86%.
Progression to NSTI: 100%
Signs present in >50% patients: erythema, tenderness, edema.
Crepitus or skin necrosis present in only 16% of patients.
Wong CH, Haw-Chong C, et all: Necrotizing fascitis:clinical presentation, microbiology, and determinants of mortality. J Bone Joint Surg Am 2003;85:

18. Radiographic Testing Plain x-ray: poor screening test.
CT scan: more sensitive (plain)
inflammatory changes
gas formation
fascial thickening: 80% sensitivity
MRI: sensitivity %, specificity 50-85%
prohibitive in critically ill, or unstable patients. (contrast-enhanced study)

20. Necrotizing fasciitis with gas forming organisms

21. Laboratory Examination
Variable
Score
C-reactive protein >150 4
WBC / >25
1 / 2
HGB / <11
Sodium <135 2
Creatinine >141 mcg/L
Glucose >10 mmol/L 1
LABORATORY RISK INDICATOR FOR NECROTIZING FASCIITIS
A sum > 6 has high correlation with NSTI (PPV:92, NPV:96)

22. Operative Findings
Operative exploration is the gold standard modality for diagnosis of NSTI
“Dishwater” or foul-smelling discharge
Necrosis
Lack of bleeding
Loss of normal resistance to the fascia.
Biopsy from interface between live and dead tissue is rarely indicated.

23. Surgical Debridement (SD)
Treatment
Surgical Debridement (SD)
Cornerstone of therapy.
Delayed SD for more than 24 h is associated with a nine fold increase in mortality (Wong and colleagues)
Wide excision to comprise healthy, bleeding tissue.
Serial debridements ( 3 spaced 12 to 36 hrs.)
Amputation is a consideration ( IV drug users).
Diverting colostomy for perineal/perianal NSTI
Open wound , wet to dry dressings.
Wound vac.
Skin grafting for large wounds.

24. Treatment
IV ABXs: Vancomycin, Linezolid, Daptomycin, quinupristin/dalfopristin, clindamycin ( G+)
Clindamycin (anaerobes)
Quinolones ( G-)
IV IG: binds staph/strep toxins limiting SIRS.
Not FDA approved.
Critically ill patients from staph. or strept.
Hyperbaric O2: controversial and unproved.
inhibits toxin elaboration by clostridia, increases local O tension and killing ability of leukocytes.

25. Morbidity and Mortality
Timing of operation the most critical determinant.
Consider age, comorbidities, DM, shock, ARF, coagulopathy….
Morbidity as high as 82% (Eliot et all)
Amputation rate 15 to 30%
Complications: nosocomial infections, respiratory failure, ARDS, ARF, seizures, stroke, cardiac arrest….

26. Future efforts Monitor changes in microbiologic causes
Enhance imaging techniques for early detection
Role of adjunctive treatments

27. LLE NSTI in alcoholic patient from C. Perfingens

28. L upper thigh NSTI in diabetic patient after insulin injection.

29. Perineal gangrene in 60 yr. old woman

30. L upper extremity NSTI from strep milleri

31. Necrotizing Fasciitis Severe infection of the inguinal region .

32. Necrotizing Fasciitis of inguinal region after debridement.

33. Necrotizing Fasciitis from group A Streptococcus (pyogenes)

34. L face debridement for Necrotizing Fasciitis

35. NSTI of R gluteal region after debridement.

36. NSTI: Necrotic tissue from the left leg is being surgically debrided.