Hand CASE 25

CASE                               25                               

A 42-year-old man presents to the hospital with pain and swelling of the dorsum of his hand. He reports blunt trauma against a metal shelf, but does not remember a break in the skin. There is a blister of the skin. He reports erythema started approximately 6 hours ago of the hand but it now extends to the wrist. He is febrile to 102 degrees, heart rate is 110, and blood pressure is 92/38. He has significant pain to palpation and induration of the dorsum of the hand.

What is the most appropriate next step in management?

1. Splinting the hand in a position of function, elevation, IV antibiotics, observation for 24 hours

2. Bedside I&D of dorsal hand abscess

3. Echocardiogram to look for valvular vegetation

4. MRI of hand to evaluate underlying abscess

5. Emergent operative debridement

 

Discussion

The correct answer is (E). The patient is febrile, tachycardic and mildly hypotensive with induration and blistering of the dorsal hand tissues, which is consistent with a diagnosis of necrotizing fasciitis. The rapid spreading of the infection precludes observation. A bedside I&D will be inadequate to debride the affected tissue and control the infection. Echocardiogram will not treat the hand infection, and necrotizing fasciitis is not associated with endocarditis. An MRI will delay the patient’s care. Rapid debridement is critical to treat necrotizing soft tissue infections.

The patient is brought to the operating room and dishwater like fluid is drained from the wound. The fascial planes are easily separated with blunt palpation.

Tissue cultures are likely to show what type of bacteria?

1. Group A, Beta hemolytic Streptococcus

2. Group B Streptococcus

3. Methicillin-resistant Staphylococcus aureus

4. Serratia marcescens

5. Clostridium perfringens

 

Discussion

The correct answer is (A). Group A Strep and polymicrobial infections are the most common causes of necrotizing fasciitis. Clostridium is also associated with necrotizing soft tissue infections (gas gangrene), but is less common than Group A Strep and polymicrobial infections. Group B strep is largely harmless to adults but is of concern during vaginal deliveries to prevent infections in the newborn. MRSA is associated with hand infections and abscesses. A toxin produced by the bacteria can damage tissue but is not a common pathogen of necrotizing soft tissue infections. Serratia marcescens is a gram-negative rod that is not associated with necrotizing soft tissue infections as an isolated pathogen.

Which of the following laboratory values is not associated with a diagnosis of

soft tissue necrotizing infection?

1. WBC ⋅ 20,000/cc

2. Creatinine ⋅ >2.0 mg/dL

3. Sodium ⋅ 135 mg/dL

4. Potassium ⋅ 3.4 mg/dL

5. Glucose ⋅ 180 mg/dL

Discussion

The correct answer is (D). The laboratory risk indicator for necrotizing fasciitis is a scoring system utilized to assist in diagnosis with a score of greater to or equal than 6 raising suspicion for necrotizing fasciitis. Hyperkalemia, not hypokalemia, is consistent with tissue damage and is associated with a poor prognosis and concern for the need for amputation.

 

C-reactive Protein	Score
<150	0
≥150	4
WBC	0
<15	1
15–25	2
>25,000
Hemoglobin	0
>13.5	1
11–13.5	2
<11
Sodium	0
≥135	2
<135
Creatinine	0
<2.0	2
>2.0
Glucose	0
<180	1
>180

 

4.24 hours after the initial debridement, the patient has a dorsal hand wound measuring 5 × 4 cm with exposed tendon. His white blood count has decreased from 25,000/cc to 17,000/cc. His temperature is 98 degrees, heart rate is 88 bpm, and blood pressure is 100/64.

What is the most appropriate next step in management?

1. Split thickness skin graft

2. Primary closure

3. Local flap coverage

4. Free flap coverage

5. Second look procedure

 

Discussion

The correct answer is (E). A second look procedure is indicated in a necrotizing soft tissue infection, particularly without complete resolution of the WBC. Because the infection spreads so quickly, it is prudent to perform repeated debridements to ensure surgical control of the infection. Twenty-four hours after the initial debridement is too early to perform closure, particularly without complete clearance of the infection. In addition, the defect is too large for primary closure. Exposed tendons will not provide a vascularized bed for a split thickness skin graft. Local flaps will not provide adequate coverage of the dorsum of the hand with this large of a defect. Free tissue transfer or regional flap (reverse radial forearm flap) would provide reliable coverage of the described wound after clearance of the infection.

 

Objectives: Did you learn...?

 

 

Recognize the presentation of necrotizing fasciitis? Describe the appropriate treatment?

 

 

Identity the bacteria that cause necrotizing fasciitis? Select the expected laboratory values?