Necrotizing Fasciitis ppt by Dr Ahmed Zubair Abbasi.pptx

Necrotizing fasciitis is a subset of aggressive skin and soft tissue infections (SSTIs) that cause necrosis of the muscle fascia and subcutaneous tissues. The infection typically travels along the fascial plane, which has a poor blood supply.

1. Necrotizing Fasciitis Zubair Abbasi 2020/058 CG-A

2. Learning objectives Definition Causes Types Clinical features Diagnosis Treatment Complications

3. Definition Necrotizing fasciitis (NF) is a rare infection that means “decaying infection of the fascia,” which is the soft tissue that is part of the connective tissue system that runs throughout the body. NF is caused by one or more bacteria that attacks the skin, the tissue just beneath the skin (subcutaneous tissue) and the fascia causing these tissues to die (necrosis).

4. Causes of NF Bacterial Infection : Necrotizing Fasciitis is primarily caused by certain types of bacteria, most commonly Streptococcus pyogenes (group A streptococcus) and Staphylococcus aureus . Other bacteria such as Clostridium species can also cause this condition. Entry Through Skin Breaks : The bacteria typically enter the body through a break in the skin, such as a cut, scrape, surgical incision, puncture wound, or insect bite. Even minor injuries that might not seem serious can provide an entry point for the bacteria. Compromised Immune System : Individuals with weakened immune systems, such as those with diabetes, chronic illnesses, cancer, or immunodeficiency disorders, are at higher risk of developing Necrotizing Fasciitis.

5. Risk Factors : Certain risk factors increase the likelihood of developing Necrotizing Fasciitis, including obesity, intravenous drug use, chronic alcoholism, peripheral vascular disease, and malnutrition. These factors can impair the body's ability to fight off infections and contribute to tissue damage. Transmission : Necrotizing Fasciitis is not contagious from person to person like a cold or flu. It occurs when bacteria already present on the skin or in the environment enter the body through a wound or injury.

6. Types of NF

7. TYPE ORGANISM CHARACTERISTICS TYPE 1 Polymicrobial Typically 4-5 aerobic and anaerobic species cultured: Non-Group A Strep Anaerobes including Clostridia Facultative anaerobes Enterobacteria 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 Fungal

8. Clinical features Severe Pain: Patients often experience severe pain in the affected area, typically disproportionate to the visible signs of infection. Swelling and Redness: The affected area may appear swollen, red, and warm to the touch. The skin may also become discolored, ranging from red to purple or black. Fever and Chills: Patients may develop a fever and experience chills as the body responds to the infection. Skin Changes: The skin over the affected area may rapidly develop blisters, ulcers, or areas of necrosis (tissue death). These changes may progress quickly, sometimes within hours.

9. Systemic Symptoms: As the infection spreads, patients may experience systemic symptoms such as malaise, fatigue, nausea, and vomiting. Rapid Progression: Necrotizing fasciitis can progress rapidly, with the infection spreading along the facial planes and causing extensive tissue damage in a short period. Crepitus: In some cases, gas produced by the bacteria may accumulate under the skin, leading to a characteristic crackling sensation (crepitus) when the affected area is palpated. Hypotension and Shock: In severe cases, necrotizing fasciitis can lead to systemic inflammation, sepsis, hypotension, and shock, which can be life-threatening if not promptly treated.

10. Diagnosis Laboratory Tests: Blood tests are conducted to evaluate markers of inflammation (such as C-reactive protein and white blood cell count) and assess for signs of systemic infection (such as elevated lactate levels). Blood cultures may be taken to identify the causative bacteria. Imaging Studies: Imaging studies such as X-rays, ultrasound, computed tomography (CT) scans, or magnetic resonance imaging (MRI) may be performed to assess the extent of tissue involvement, identify areas of gas formation (which can indicate severe infection), and aid in surgical planning. Surgical Exploration: In some cases, surgical exploration and tissue biopsy may be necessary to confirm the diagnosis. During surgery, the surgeon can directly visualize the affected tissue, assess its viability, and obtain tissue samples for culture and histopathological examination.

11. Extensive soft tissue gas involving the right hand and visualized right forearm.

12. Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score  A LRINEC score of ≥6 should raise the suspicion of necrotizing fasciitis, and a score of ≥8 is strongly predictive of this disease.

13. Treatment Surgical: Prompt surgical intervention is the cornerstone of treatment for necrotizing fasciitis. Surgical debridement involves the removal of necrotic (dead) tissue and infected material to halt the spread of the infection. In severe cases, amputation of affected limbs or surgical interventions to control hemorrhage may be necessary. Broad-Spectrum Antibiotics: Empirical broad-spectrum antibiotics are initiated immediately upon suspicion of necrotizing fasciitis and are adjusted based on culture and sensitivity results. Antibiotics are typically administered intravenously to achieve high tissue concentrations. Coverage often includes antibiotics effective against common causative organisms such as Streptococcus pyogenes , Staphylococcus aureus (including methicillin-resistant strains), and anaerobic bacteria.

14. Supportive Care: Supportive measures may include intravenous fluids, electrolyte replacement, and nutritional support to maintain the patient's overall health and prevent complications such as dehydration and malnutrition. Patients may require monitoring in an intensive care unit (ICU) for hemodynamic stability and close observation for signs of systemic inflammation and organ dysfunction. Pain Management: Adequate pain management is essential, given the severe pain associated with necrotizing fasciitis. Analgesics, including opioids, may be used to alleviate pain and improve patient comfort. Monitoring and Follow-up: Patients require close monitoring during treatment to assess response to therapy, monitor for complications, and ensure wound healing. Long-term follow-up may be necessary to address potential complications such as chronic pain, functional impairment, and psychological sequelae .

15. Complication It can also result in life-long complications from  loss of limbs or severe scarring due to surgically removing infected tissue. Looking at data from the most recent five years: Even with treatment, up to 1 in 5 people with necrotizing fasciitis died from the infection.

16. References https://www.tamingthesru.com/blog/2018/9/3/necrotizing-fasciitis-and-the-spectrum-of-soft-tissue-infections https://radiopaedia.org/articles/necrotising-fasciitis https://www.icliniq.com/articles/infectious-diseases/necrotizing-fasciitis https://www.orthobullets.com/trauma/1007/necrotizing-fasciitis

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