questions 5

Necrotizing Fasciitis

Topic updated on 08/04/15 11:03pm

Snap Shot
  • PhotoA 45-year-old woman presents to the emergeny room with an infection on her hand that started with a bee sting on knuckle of her long finger and has spread to the distal wrist in two days. She is extremely concerned because her finger tips and the dorsal surface of her hand have started to turn purple and black.
  • Infection that spreads along fascial planes
  • Characterized by rapid progression to necrosis and gangrene followed by sepsis
  • Often involves multiple aerobic and anaeobic organisms simultaneously
  • Most common pathogens include
    • S. pyogenes (Group A strep)  
    • Clostridium perfringens
      • identifed by subsequent crepitus palpable at the surface along sites of infection
  • Symptoms
    • severe pain at sites of infection
    • fever
  • Physical exam
    • patients appear severely ill
    • surface crepitus
      • may be noted along sites of infection due to gas-producing bacteria
  • Labs
    • elevated WBC
  • Culture and Sensitivities
    • critical for identifying pathogens and direct therapy, however, usually polymycrobial and coverage is empiric
  • Cellulitis 
  • Operative
    • early IV antibiotics and surgical debridement   
      • antibiotics
        • IV penicillin and clindamycin
          • indicated in all cases as first-line therapy
          • broad-spectrum systemic antibiotics are critical to slow or prevent further spread of infection
        • sensitivity-guided antibiotic therapy
          • implement as soon as culture results are reported
      • surgical debridement
        • indicated to prevent further spread along fascial planes
        • must be immediate and extensive
Prognosis, Prevention, and Complications
  • Prognosis
    • poor to lethal in most cases
  • Prevention
    • proper care of superficial wounds can prevent deeper spread of bacteria
  • Complications
    • high mortality if debridement is not performed immediately and extensively


Qbank (2 Questions)

(M2.DM.5) A 27-year-old man comes to the emergency department complaining of extreme pain in his left calf. He is a surfer and cut his leg on a reef over the weekend. He says he cleaned the wound himself and bandaged it, but has been having worsening pain. On exam, T is 101.8 F, HR is 108 bpm, RR 18 rpm, and BP 115/75 mmHg. The man's leg is exquisitely tender and shown in Image A. You note crepitus on palpation. Which of the following is most appropriate next step? Topic Review Topic
FIGURES: A          

1. Watchful waiting
2. Wound culture for directed antibiotic treatment
3. Empiric antibiotic coverage
4. Empiric antibiotic coverage and surgical debridement
5. Amputation

(M2.DM.73) A 47-year-old female presents to the emergency department in distress with a wound on her right lower leg. The patient describes intense pain over the site yesterday that has since dissipated; she is now insensate and not in pain. She also states that the area has been changing colors from first red to now purple/black. She reports having been stung by a bee near that spot 2 days ago. Her medical history is significant for type II diabetes, which is controlled with glipizide, and chronic headaches, for which she regularly takes naproxen. Her vital signs are as follows: T 38.9 C, HR 109, BP 80/57, RR 22, and SpO2 96%. Physical examination shows a 5cm x 12cm wound over the anterior right lower leg that is discolored purple and black towards the center of the wound with expanding edema and erythema towards the edges (Figure A). The area is insensate to light touch and pin-prick. No crepitus is noted on palpation of the wound. Which of the following is the most likely causative organism in this patient's presentation? Topic Review Topic
FIGURES: A          

1. Staphylococcus aureus
2. Streptococcus pyogenes
3. Pseudomonas aeuroginosa
4. Escherichia coli
5. Clostridium botulinum


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