Management of Perineal necrotizing fasciitis: Guideline by WSES/AAST
M3 India Newsdesk May 12, 2022
This article elucidates the Guidelines from the World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST) that provide key recommendations for the management of perineal necrotizing fasciitis along with the proposed antibiotic regimens.
What is perineal necrotizing fasciitis?
Perineal necrotizing fasciitis or Fournier’s gangrene is a rare and potentially life-threatening necrotizing infection. The condition affects the fascia and subcutaneous tissues of the external genitalia or perineum. Empiric antimicrobial therapy should be started as soon as the diagnosis is suspected.
Perineal necrotizing fasciitis is a time-sensitive disease, which spreads quickly and widely. The infection rapidly spreads cranially to the abdominal wall and caudally to the legs. Testicular involvement is rare. Prompt diagnosis and treatment are critical but challenging.
Guidelines from the World Society of Emergency Surgery WSES and the American Association for the Surgery of Trauma AAST are as follows:
1. Clinical examination and biochemical investigations in patients with suspected Fournier’s gangrene
- In patients with suspected Fournier’s gangrene, it is suggested to collect a focused medical history and carry out a complete physical examination, including a digital rectal examination.
- Careful inspection of the perineum is mandatory.
- Perineal and/or scrotal pain, swelling, and erythema are the most common symptoms of Fournier’s gangrene. Fever and tachycardia are also present.
- Physical examination may reveal purulent discharge, crepitus (subcutaneous emphysema), and patches of the necrotic tissue with surrounding oedema. Cutaneous manifestations usually appear later in the disease process as these patches progress to florid gangrene.
- In patients with suspected Fournier's gangrene and signs of systemic infection or sepsis, it is suggested to carry out a complete blood count and the dosage of serum creatinine and electrolytes, inflammatory markers (e.g., C-reactive protein, procalcitonin) and blood gas analysis. Serum glucose, hemoglobinA1c, and urine ketones are also recommended to investigate undetected diabetes mellitus.
- The laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) score can be used for an early diagnosis. Fournier’s Gangrene Severity Index (FGSI) can help in evaluating prognosis and risk stratification.
2. Imaging investigations in Fournier’s gangrene
- A CT scan should be performed in stable patients with suspected Fournier’s gangrene.
- CT imaging is not recommended in patients with Fournier’s gangrene and hemodynamic instability (persisting after proper resuscitation).
- In patients with Fournier’s gangrene, the imaging investigations should not delay surgical intervention.
3. Surgery in patients with Fournier’s gangrene
- In patients with Fournier’s gangrene, surgical intervention should be carried out as soon as possible.
- Repeat surgical revisions (exploration and debridement) should be planned according to patient conditions. Seriated surgical revisions are suggested until the patient is free of necrotic tissue.
- In patients with Fournier’s gangrene, it is suggested to remove all the necrotic tissue.
- A multidisciplinary and tailored approach is suggested after considering the extent of perineal involvement, the degree of faecal contamination, and the possible presence of sphincter or urethral damage.
- Orchiectomy or other genital surgery should be performed only if strictly necessary and possibly after urologic consultation.
- The surgical management of early and delayed surgical sequelae should always be planned with a multidisciplinary and skilled team.
4. Antibiotic regimen in patients with Fournier’s gangrene
- Antibiotic treatment of Fournier’s gangrene should be prompt and aggressive. Empiric antimicrobial therapy should be started as soon as the diagnosis is suspected.
- The initial coverage should be broad and include cover for gram-positive, gram-negative, aerobic and anaerobic bacteria, and an anti-MRSA agent.
- It is recommended to obtain microbiological samples at the index operation to allow modification of the drug regimen based on the specific cultured pathogens.
- Antimicrobial de-escalation should be done after considering the clinical improvement, cultured pathogens, and results of rapid diagnostic tests where available.
- The WSES/SIS-E guideline should be referred for a detailed discussion of the management of skin and soft-tissue infections.
Proposed antibiotic regimens
In stable patients- Piperacillin/tazobactam 4.5 g 6-hourly + Clindamycin 600 mg 6-hourly
In unstable patients
One of the following antibiotics can be prescribed:
- Piperacillin/tazobactam 4.5 g 6-hourly
- Meropenem 1 g 8-hourly
- Imipenem/Cilastatin500 mg 6-hourly
+ One of the following antibiotics:
- Linezolid 600 mg 12-hourly
- Tedizolid 200 mg 24-hourly
Another anti-MRSA-antibiotic as:
- Vancomycin 25–30 mg/kg loading dose then 15–20 mg/kg/dose 8-hourly
- Teicoplanin loading dose 12 mg/kg 12-hourly for 3 doses, then 6 mg/kg 12-hourly
- Daptomycin 6–8 mg/kg 24-hourly (*Approved at the dosage of 4 mg/kg/24 h, it is currently used at higher dosages)
- Telavancin 10 mg/kg 24-hourly
- Clindamycin 600 mg 6-hourly
The guidelines for the management of anorectal issues by WSES and AAST will be discussed in this series pertaining to different conditions-Click here to read the previous parts-Anorectal abscess: Management guideline updates by WSES and AAST
Click here to see references
Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.
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