Necrotizing fasciitis: Difference between revisions

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==Background==
==Background==
Necrotizing fasciitis is a rare, rapidly progressive infection primarily involving the fascia and subcutaneous tissue. It is perhaps the most severe form of soft tissue infection and is potentially limb
*A rapidly progressive infection primarily involving the fascia and subcutaneous tissue
and life threatening. Early recognition and aggressive debridement of all necrotic fascia and subcutaneous tissue aremajor prognostic determinants, and delay increases mortality. <ref>Wong CH, Khin LW, Heng KS, Tan KC, Low CO (2004). "The LRINEC Laboratory Rother soft tissue infections". Critical Care Medicine 32 (7): 1535–1541. doi:10.1097/01.CCM.0000129486.35458.7D. PMID 15241098</ref>
*Formerly a rare diagnosis, frequency has risen due to an increase in immunocompromised patients with significant risk factors<ref>Hakkarainen TW et al. Necrotizing soft tissue infections: review and current concepts in treatment, systems of care, and outcomes. Curr Probl Surg. 2014 Aug. 51 (8):344-72.</ref>
*Gas-formation is NOT a requirement for diagnosis, and radiographical lack of the classically taught gas formation should NEVER rule out necrotizing infection<ref>Misiakos EP et al. Current concepts in the management of necrotizing fasciitis. Front Surg. 2014. 1:36.</ref>
*Most severe form of soft tissue infection and potentially limb and life threatening
*Early recognition and aggressive debridement are major prognostic determinants and delay increases mortality<ref>Wong CH, Khin LW, Heng KS, Tan KC, Low CO (2004). "The LRINEC Laboratory Rother soft tissue infections". Critical Care Medicine 32 (7): 1535–1541. doi:10.1097/01.CCM.0000129486.35458.7D. PMID 15241098</ref>
 
===Categories===
*Type I, polymicrobial
*Type II, [[group A streptococcal]]
*Type III, gas gangrene or [[clostridial]] myonecrosis
 
===Risk Factors===
===Risk Factors===
*[[DM]]
*[[DM]]
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==Clinical Features==
==Clinical Features==
[[File:NectrotizingFasciitis.jpeg|thumbnail|Nectrotizing fasciitis]]
[[File:NectrotizingFasciitis.jpeg|thumb|Nectrotizing fasciitis]]
*Skin exam
*Skin exam
**Erythema (without sharp margins)
**Erythema (without sharp margins)
**Exquisitely tender (pain out of proportion to exam)
**Exquisitely tender (pain out of proportion to exam)
***Caveat - some patients present with "la belle indifference"
***May be a result of ischemic, insensate tissue<ref>TheHealthScience. Emergent Management of Necrotizing Soft Tissue Skin Infections. Nov 22, 2013. https://thehealthscience.com/topics/emergent-management-necrotizing-soft-tissue-skin-infections.</ref>
**Skip lesions
**Skip lesions
**Hemorrhagic bullae (violaceous bullae)
**Hemorrhagic bullae (violaceous bullae)
***May be preceded by skin anesthesia (destruction of superficial nerves)
***May be preceded by skin anesthesia (destruction of superficial nerves)
**Crepitus (in type I infections)
**Crepitus (in type I infections)
**Lymphangitis and lymphadenopathy are absent in necrotizing fasciitis alone<ref>Seal DV. Necrotizing fasciitis. Curr Opin Infect Dis. 2001;14(2):127–32.</ref><ref>Golger A, Ching S, Goldsmith CH, Pennie RA, Bain JR. Mortality in patients with necrotizing fasciitis. Plast Reconstr Surg. 2007;119(6):1803–7.</ref>
***Lymphangitis is seen in [[cellulitis]]
***Fascia has no lymph drainage
*Swelling/edema may produce compartment syndrome
*Swelling/edema may produce compartment syndrome
*Constitutional
*Constitutional or toxic shock-like syndrome<ref>Puvanendran R et al. Necrotizing fasciitis. Can Fam Physician. 2009 Oct; 55(10): 981–987.</ref>
**Fever
**Fever
**Tachycardia
**Tachycardia
**Systemic toxicity
**Systemic toxicity, [[sepsis]]
**[[Conjunctivitis]]


==Work-Up==
==Differential Diagnosis==
{{SSTI DDX}}
{{Necrotizing Rashes DDX}}
 
==Evaluation==
[[File:CTNecrotizingFasciitis.png|thumb|CT of necrotizing fasciitis]]
===Work-Up===
*CBC
*CBC
*Chem
*Chem
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*Lactate
*Lactate


==Diagnosis==
===Evaluation===
[[File:CTNecrotizingFasciitis.png|thumbnail|CT of necrotizing fasciitis]]
*Surgical exploration is the ONLY way to definitively establish the diagnosis of necrotizing infection
*Surgical exploration is the ONLY way to definitively establish the diagnosis of necrotizing infection
*Imaging
*Imaging
**Should not delay surgical exploration
**Should not delay surgical exploration
**CT is study of choice
**CT is study of choice - soft tissue gas, edema and fluid collections, fascial thickening with fat stranding
**US may show thickened fascial planes, fluid between fascial planes, irregularity of the fascia, subcutaneous emphysema. The study may be limited by soft tissue gas. Video lecture<ref>Soft Tissue Ultrasound with Jacob Avila on Core Ultrasound. https://www.coreultrasound.com/sti/</ref>.
**MRI - T2 subcutaneous, intramuscular, and fascial edema
*Absence of gas on imaging '''does not''' exclude diagnosis, as gas may be occult and/or certain organisms do not classically produce gas (i.e. [[Streptococcus|Group A Strep]])
{{LRINEC SCORE}}


===HUCLA NF vs Non-NF Criteria (Wall et al)===
===HUCLA NF vs Non-NF Criteria:<ref>Wall DB et al. A simple model to help distinguish necrotizing fasciitis from nonnecrotizing soft tissue infection. J Am Coll Surg. 2000 Sep;191(3):227-31.</ref>===
*Retrospective study discovered:<ref>Wall DB et al. A simple model to help distinguish necrotizing fasciitis from nonnecrotizing soft tissue infection. J Am Coll Surg. 2000 Sep;191(3):227-31.</ref>
*Retrospective study discovered:
**'''WBC count''' '''>15.4'''(x10<sup>3</sup>/mm<sup>3</sup>) OR '''Na''' '''<135'''(mmol/L)  
**'''WBC count''' '''>15.4'''(x10<sup>3</sup>/mm<sup>3</sup>) OR '''Na''' '''<135'''(mmol/L)  
**Associated with NF and combo of both increased likelihood of NF
**Associated with NF and combo of both increased likelihood of NF
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**Helps distinguish NF from non-NF infection, when classic 'hard' signs of NF are absent however clinical judgment should still be used in patient with high suspicion of the disease
**Helps distinguish NF from non-NF infection, when classic 'hard' signs of NF are absent however clinical judgment should still be used in patient with high suspicion of the disease


===[[EBQ:LRINEC Score|Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score (Wong et al)]]===
==Management==
{{LRINEC SCORE}}
 
==Differential Diagnosis==
{{Template:SSTI DDX}}
 
==Treatment==
*Surgical exploration and debridement is both the definitive diagnostic modality and the definitive treatment
*Surgical exploration and debridement is both the definitive diagnostic modality and the definitive treatment
**Indicated in setting of severe pain, toxicity, fever, elevated CK (w/ or w/o radiographic evidence)
**Indicated in setting of severe pain, toxicity, fever, elevated CK (with or without radiographic evidence)
*[[Antibiotics]]
*[[Antibiotics]]
**Must cover Gram +/- and anaerobes (esp GAS and clostridium)
**Must cover [[gram positives]], [[gram negatives]], and [[anaerobes]] (especially [[GAS]] and [[clostridium]])
**[[Piperacillin-Tazobactam]] 3.375-4.5g q6hr AND [[clindamycin]] 600-900mg q8hr AND [[vancomycin]] 1gm IV q12hr
**[[Piperacillin-Tazobactam]] 3.375-4.5g q6hr AND [[clindamycin]] 600-900mg q8hr AND [[vancomycin]] 1gm IV q12hr (consider weight base dosing of 20 mg/kg)
*Diabetics
**[[Piperacillin-Tazobactam]] 3.375-4.5g q6hr and [[linezolid]] 600mg q12hr is an alternative regimen<ref>Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America [published correction appears in Clin Infect Dis. 2015 May 1;60(9):1448. Dosage error in article text]. Clin Infect Dis. 2014;59(2):e10-e52. doi:10.1093/cid/ciu444</ref>
**IVFs and IV Insulin (with high POCT glucose) for glycemic control (after paging surgery)
*In diabetics, maintain strict glycemic control (with [[IVFs]] and IV [[insulin]] if necessary)


==Disposition==
==Disposition==
Admit/OR
*Admit to ICU


==See Also==
==See Also==
*[[Necrotizing Soft Tissue Infections]]
*[[Necrotizing soft tissue infections]]
*[[LRINEC_score|Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score]]
*[[EBQ:LRINEC Score]]


==Source==
==References==
<references/>
<references/>


[[Category:ID]]
[[Category:ID]]

Latest revision as of 20:11, 17 April 2024

Background

  • A rapidly progressive infection primarily involving the fascia and subcutaneous tissue
  • Formerly a rare diagnosis, frequency has risen due to an increase in immunocompromised patients with significant risk factors[1]
  • Gas-formation is NOT a requirement for diagnosis, and radiographical lack of the classically taught gas formation should NEVER rule out necrotizing infection[2]
  • Most severe form of soft tissue infection and potentially limb and life threatening
  • Early recognition and aggressive debridement are major prognostic determinants and delay increases mortality[3]

Categories

Risk Factors

  • DM
  • Drug use
  • Obesity
  • Immunosuppression
  • Recent surgery
  • Traumatic wounds

Clinical Features

Nectrotizing fasciitis
  • Skin exam
    • Erythema (without sharp margins)
    • Exquisitely tender (pain out of proportion to exam)
      • Caveat - some patients present with "la belle indifference"
      • May be a result of ischemic, insensate tissue[4]
    • Skip lesions
    • Hemorrhagic bullae (violaceous bullae)
      • May be preceded by skin anesthesia (destruction of superficial nerves)
    • Crepitus (in type I infections)
    • Lymphangitis and lymphadenopathy are absent in necrotizing fasciitis alone[5][6]
      • Lymphangitis is seen in cellulitis
      • Fascia has no lymph drainage
  • Swelling/edema may produce compartment syndrome
  • Constitutional or toxic shock-like syndrome[7]

Differential Diagnosis

Skin and Soft Tissue Infection

Look-A-Likes

Necrotizing rashes

Evaluation

CT of necrotizing fasciitis

Work-Up

  • CBC
  • Chem
  • PT/PTT/INR
  • CK
  • Lactate

Evaluation

  • Surgical exploration is the ONLY way to definitively establish the diagnosis of necrotizing infection
  • Imaging
    • Should not delay surgical exploration
    • CT is study of choice - soft tissue gas, edema and fluid collections, fascial thickening with fat stranding
    • US may show thickened fascial planes, fluid between fascial planes, irregularity of the fascia, subcutaneous emphysema. The study may be limited by soft tissue gas. Video lecture[8].
    • MRI - T2 subcutaneous, intramuscular, and fascial edema
  • Absence of gas on imaging does not exclude diagnosis, as gas may be occult and/or certain organisms do not classically produce gas (i.e. Group A Strep)

Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score[9]

Has not been prospectively validated, index of suspicion is key and 10% of the patients with a score < 6 had Necrotizing Fasciitis. A score > 6 has PPV of 92% and NPV of 96% for necrotizing fasciitis.

  1. CRP (mg/L) ≥150: 4 points
  2. WBC count (×103/mm3)
    • <15: 0 points
    • 15–25: 1 point
    • >25: 2 points
  3. Hemoglobin (g/dL)
    • >13.5: 0 points
    • 11–13.5: 1 point
    • <11: 2 points
  4. Sodium (mmol/L) <135: 2 points
  5. Creatinine (umol/L) >141: 2 points
  6. Glucose >180 mg/dL (10 mmol/L): 1 point

Grouping by Scores

  • Low Risk: score 5 (10% of pts with score < 6 still had nec fasc)
  • Moderate Risk: score 6– 7
  • High Risk: score >8

Proposed algorithm

HUCLA NF vs Non-NF Criteria:[10]

  • Retrospective study discovered:
    • WBC count >15.4(x103/mm3) OR Na <135(mmol/L)
    • Associated with NF and combo of both increased likelihood of NF
    • PPV 26%/NPV 99%
  • Useful tool to rule out NF, not a good tool for confirming presence of NF
    • Helps distinguish NF from non-NF infection, when classic 'hard' signs of NF are absent however clinical judgment should still be used in patient with high suspicion of the disease

Management

Disposition

  • Admit to ICU

See Also

References

  1. ↑ Hakkarainen TW et al. Necrotizing soft tissue infections: review and current concepts in treatment, systems of care, and outcomes. Curr Probl Surg. 2014 Aug. 51 (8):344-72.
  2. ↑ Misiakos EP et al. Current concepts in the management of necrotizing fasciitis. Front Surg. 2014. 1:36.
  3. ↑ Wong CH, Khin LW, Heng KS, Tan KC, Low CO (2004). "The LRINEC Laboratory Rother soft tissue infections". Critical Care Medicine 32 (7): 1535–1541. doi:10.1097/01.CCM.0000129486.35458.7D. PMID 15241098
  4. ↑ TheHealthScience. Emergent Management of Necrotizing Soft Tissue Skin Infections. Nov 22, 2013. https://thehealthscience.com/topics/emergent-management-necrotizing-soft-tissue-skin-infections.
  5. ↑ Seal DV. Necrotizing fasciitis. Curr Opin Infect Dis. 2001;14(2):127–32.
  6. ↑ Golger A, Ching S, Goldsmith CH, Pennie RA, Bain JR. Mortality in patients with necrotizing fasciitis. Plast Reconstr Surg. 2007;119(6):1803–7.
  7. ↑ Puvanendran R et al. Necrotizing fasciitis. Can Fam Physician. 2009 Oct; 55(10): 981–987.
  8. ↑ Soft Tissue Ultrasound with Jacob Avila on Core Ultrasound. https://www.coreultrasound.com/sti/
  9. ↑ Wong C. "The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections". Crit Care Med. 2004. 32(7):1535-41.
  10. ↑ Wall DB et al. A simple model to help distinguish necrotizing fasciitis from nonnecrotizing soft tissue infection. J Am Coll Surg. 2000 Sep;191(3):227-31.
  11. ↑ Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America [published correction appears in Clin Infect Dis. 2015 May 1;60(9):1448. Dosage error in article text]. Clin Infect Dis. 2014;59(2):e10-e52. doi:10.1093/cid/ciu444
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