|
https://upload.orthobullets.com/topic/1007/images/flesh_eaten[1]_moved.jpg
https://upload.orthobullets.com/topic/1007/images/lrinec_1.jpg
https://upload.orthobullets.com/topic/1007/images/screen_shot_2017-04-02_at_9.29.47_am.jpg
https://upload.orthobullets.com/topic/1007/images/screen_shot_2017-04-02_at_9.29.27_am.jpg
https://upload.orthobullets.com/topic/1007/images/screen_shot_2017-04-02_at_9.28.33_am.jpg
https://upload.orthobullets.com/topic/1007/images/screen_shot_2017-04-02_at_9.28.11_am.jpg
https://upload.orthobullets.com/topic/1007/images/screen_shot_2017-04-02_at_9.28.01_am.jpg
Introduction
  • Necrotizing fasciitis is a life threatening infection that spreads along soft tissue planes
  • Risk factors
    • immune suppression
      • diabetes
      • AIDS
      • cancer
    • bacterial introduction
      • IV drug use
      • hypodermic therapeutic injections
      • insect bites
      • skin abrasions
      • abdominal and perineal surgery
    • other host factors
      • obesity
  • Associated conditions
    • cellulitis
      • overlying cellulitis may or may not be present
  • Prognosis
    • life threatening infection
      • mortality rate of 32%
      • mortality correlates with time to surgical intervention
Classification
 
 Necrotizing Fasciitis Classification
Type Organism Characteristics
Type 1 q Polymicrobial
Typical 4-5 aerobic and anaerobic species cultured:
• non-Group A Strep
• anaerobes including Clostridia
• facultative anaerobes
• enterobacteria
• Synergistic virulence between organisms
 • Most common (80-90%)
 • Seen in immunosuppressed (diabetics and cancer patients)
 • Postop abdominal and perineal infections
Type 2  Monomicrobial
• Group A β-hemolytic Streptococci is most common organism isolated
 • 5% of cases
 • Seen in healthy patients
 • Extremities
Type 3 Marine Vibrio vulnificus
(gram negative rods)
 • Marine exposure
Type 4 MRSA  
 
Presentation
  • Symptoms
    • early
      • localized abscess or cellulitis with rapid progression
      • minimal swelling
      • no trauma or discoloration
    • late findings
      • severe pain
      • high fever, chills and rigors
      • tachycardia
  • Physical exam      
    • skin bullae
    • discoloration 
      • ischemic patches
      • cutaneous gangrene
    • swelling, edema
    • dermal induration and erythema
    • subcutaneous emphysema (gas producing organisms)
Imaging
  • Radiographs
    • not required for diagnosis or treatment
Differentials
  • Gas gangrene 
Studies
  • Biopsy 
    • indications
      • emergent frozen section can confirm diagnosis in early cases 
    • technique
      • take 1x1x1cm tissue sample
      • can be performed at bedside or in operating room
      • surgical intervention should not be delayed to obtain
    • histological findings
      • necrosis of fascial layer
      • microorganisms within fascial layer
      • PMN infiltration
      • fibrinous thrombi in arteries and veins and necrosis of arterial and venous walls
  • LRINEC Scoring system
    • score > 6 has PPV of 92% of having necrotizing fasciitis
      • CRP (mg/L) 
        • ≥150: 4 points
      • WBC count (×103/mm3)
        • <15: 0 points
        • 15–25: 1 point
        • >25: 2 points
      • Hemoglobin (g/dL)
        • >13.5: 0 points
        • 11–13.5: 1 point
        • <11: 2 points
      • Sodium (mmol/L)
        • <135: 2 points
      • Creatinine (umol/L)
        • >141: 2 points
      • Glucose (mmol/L)
        • >10: 1 point
Treatment
  • Operative
    • emergency radical debridement with broad-spectrum IV antibiotics post q 
      • indications
        • whenever suspicion for necrotizing fasciitis
      • operative findings
        • liquefied subcutaneous fat
        • dishwater pus
        • muscle necrosis
        • venous thrombosis
      • technique
        • hemodynamic monitoring with systemic resuscitation is critical
        • hyperbaric oxygen chamber if anaerobic organism identified
      • antibiotics
        • initial antibiotics
          • start empirically with penicillin, clindamycin, metronidazole, and an aminoglycoside
        • definitive antibiotics
          • penicillin G
            • for strep or clostridium
          • imipenem or doripenem or meropenem
            • for polymicrobial
          • add vancomycin or daptomycin
            • if MRSA suspected
    • amputation
      • indications
        • low threshold for amputation when life threatening
 

Please rate topic.

Average 4.3 of 50 Ratings

Questions (6)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(OBQ10.89) Poor outcomes with necrotizing fasciitis have been associated with which of the following factors? Review Topic

QID: 3177
1

Pre-existing cardiac dysfunction

1%

(15/2822)

2

Polymicrobial infection

2%

(69/2822)

3

Use of hyperbaric oxygen

1%

(26/2822)

4

Intravenous drug abuse

1%

(31/2822)

5

Delay in time to diagnosis

95%

(2675/2822)

Select Answer to see Preferred Response

PREFERRED RESPONSE 5

(OBQ12.136) A 16-year-old male presents to the emergency department one day after scratching his leg on a piece of scrap metal. He reports a progressive rash on his leg that has advanced over the last several hours. In the emergency room his temperature is 102.8 degrees and his systolic blood pressure is 98 mmHg. On physical exam the clinical finding shown in Figure A is found. What would be the most appropriate next step in treatment. Review Topic

QID: 4496
FIGURES:
1

MRI

17%

(733/4325)

2

Biopsy with urgent frozen section in the operating room

57%

(2485/4325)

3

Needle aspiration

10%

(423/4325)

4

CT

8%

(364/4325)

5

Ultrasound

7%

(295/4325)

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

(OBQ04.217) A 52-year-old diabetic male sustained minor blunt trauma to his left thigh 10 hours prior to presentation. He initially complained of extreme thigh pain with erythema and swelling but rapidly developed bullae and worsening erythema over the affected area along with fever and tachycardia. A clinical photo is shown in Figure A. What clinical factor has been shown to reduce mortality when treating this pathology? Review Topic

QID: 1322
FIGURES:
1

Presence of MRI findings

0%

(1/377)

2

Administration of pressors

1%

(2/377)

3

Decreasing time from admission to surgery

95%

(360/377)

4

Immediate identification of causative organism

2%

(8/377)

5

Location of injury

1%

(5/377)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3

(OBQ04.264) A 56-year-old diabetic male presents to the emergency department by ambulance after developing high-grade fevers, malaise, and altered mental status. Upon presentation, he is found to be hypotensive and initial labs show an elevated WBC with a profound left shift. Figure A shows skin manifestations confined to the foot at initial presentation. He is started on broad spectrum antibiotics. Upon follow-up exam 3 hours later his clinical condition deteriorates (Figure B) and he is taken to the operating room for surgical debridement. In a bacterial culture, what would be the most common single isolate for this condition? Review Topic

QID: 1369
FIGURES:
1

Staphylococcus aureus

17%

(309/1783)

2

Staphylococcus epidermidis

2%

(33/1783)

3

Group A streptococcus

76%

(1348/1783)

4

Enterobacteriaceae

1%

(16/1783)

5

Pseudomonas

4%

(64/1783)

Select Answer to see Preferred Response

PREFERRED RESPONSE 3
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
ARTICLES (16)
VIDEOS (1)
GROUPS (1)
Topic COMMENTS (13)
Private Note