Necrotizing Fasciitis

Necrotizing Fasciitis:

Necrotizing Fasciitis BY Hosam Mohammad Hamza, Msc Assistant lecturer of GI Surgery & Endsocopy Minia Faculty of Medicine Minia-Egypt

Outline recent:

Outline recent Definition Causes. Pathophysiology. Clinical features. Diagnosis D.D. Complications. Treatment

Definition :

Definition A progressive life-threatening soft-tissue infection (with liquifactive necrosis of subcutaneous fat and fascia) ± skin . Cheng NC, Su YM, Kuo YS, Tai HC, Tang YB. Factors affecting the mortality of necrotizing fasciitis involving the upper extremities. Surg Today . 2008;38(12):1108-13. ” التهــاب اللِّـــفَافَة المــُنخِـــر“

Causes:

Causes Surgery may induce local tissue injury and bacterial invasion (e.g. intraperitoneal or perianal abscesses) Trauma. IM injections. Local hypoxia with systemic illnes s ( immunosuppression or DM  compromise of the fascial blood supply ) Schwartz’s principles of surgery, 9 th ed. A possible relationship between the use of NSAIDs ( as ibuprofen ) and development of necrotizing fasciitis during varicella infections have been shown. Zerr DM, Alexander ER, Duchin JS, et al . A case - control study of necrotizing fasciitis during primary varicella . Pediatrics . Apr 1999;103 ( 4 Pt 1 ): 783-90 .

Idiopathic necrotizing fasciitis :

Idiopathic necrotizing fasciitis No obvious portal of entry. typically involves genetalia ( Fourniere Gangrene ) or lower extremities. caused by single organism (e.g. Strep. pyogenes) May be due to unrecognized breaks in skin or hematogenous spread

Pathophysiology:

Pathophysiology 1ry site of pathology is the superficial fascia. Surgery / Trauma  tissue hypoxia  PMNL dysfunction  good environment for f acultative aerob es  more ↓ oxidation  proliferat ion of anaerobic bacteria  angiothrombotic microbial invasion  liquefactive necrosis Microbiology: - G roup A h a emolytic streptococci . - Staph. Aureus. - O ther s : Bacteroides, Clostridium, and ( Vibrio vulnificus often in chronic liver D .) - Fungi (Rare and less aggressive forms) SCH A erobic metabolism  C o 2 + H 2 O . Ana erobic metabol .  H, N , H 2 S.

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Type I Polymicrobial ( aerobic and anaerobi c) C ommon with DM and PVD, after surgical procedures Type II - Monomicrobial (primarily by GAS, occasionally caused by community-associated MRSA).

Clinical features:

Clinical features ♂ : ♀ ratio = 2-3 : 1, adult or elderly. History of recent trauma or surgery. sudden onset of pain and swelling . hours to days anaesthesia . Early Diagnosis can be challenging as p hysical findings may be out of proportion with degree of patient discomfort (high degree of suspicion is mandatory).

Physical findings:

Physical findings Toxaemia (esp. late) area of erythema quickly spreads into normal skin without sharp demarcation dusky or purplish skin m ultiple identical patches of gangrenous skin - large area of skin gangren e. Bullae with putrid discharge. Local crepitus (infrequent) Fascial necrosis . Without ttt  myonecrosis. Fever. Shock. MOF

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Important distinguishing features: SAB wooden hard feel of subcut. Tissue. If an open wound  probing allows easy dissection of superficial fascial planes beyound wound margins with little pain.

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Source: Brunicardi FC, Andersen DK, Billiar TR, Dunn DL: Schwatrz’s Principles of Surgery. 9 th ed . All rights reserved

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Fourniere G After dental infections Post-traumatic Postop

Can affect any part of body:

Can affect any part of body Perineum : neglected ischiorectal/perineal abscess. Vulva: Bartholin’s gland duct abscess vulvar abscess post-op wound infection from C-section or episiotomy. Fourniere gangrene: GU infection or surgery. traumatic instrumentation Scalp/Periorbital : trauma, eyelid infections. Face/Neck : progressive dental infections, peritonsillar abscess, salivary gland infections, cervical adenitis, otologic sources - Trauma drug abuse insect bites (rare). post-op complication of abd surgery Complication of percutaneous catheter placement: chest tube or percutaneous drain of abd. abscess

Diagnosis:

Diagnosis It is mainly a Clinical Diagnosis . LAB: LRINEC L ab R isk I ndicator for NEC rotizing fascii. > 6 should raise suspicion of NF > 8 is highly predictive of NF Imaging PARAMETER POINTS CRP > 150 mg/L 4 Leucocytosis 15 – 25 X 103 > 25 X 103 1 2 Hb 11 – 13 g% < 11 g% 1 2 Serum Na < 135 Meq / L 2 Serum Glucose > 180 mg % 1

acute inflammatory cells in the necrotic tissue. - Bacteria are located in the haziness of their cytoplasm. - Obliterative thrombosis of a,v CURR:

acute inflammatory cells in the necrotic tissue . - Bacteria are located in the haziness of their cytoplasm. - Obliterative thrombosis of a,v CURR Imaging techniques ( such as MRI ) and frozen section biopsies, have been reported to be of value in early recognition of necrotizing fasciitis . Curr Opin Infect Dis 18:101–106. # 2005 Lippincott Williams & Wilkins.

D.D:

D.D Clinical Findings Type 1 Type 2 Gas Gangrene Pyomyositis Myositis viral/ parasitic Fever ++ ++++ +++ ++ ++ Diffuse Pain + + + + ++++ Local Pain ++ ++++ ++++ ++ ++ Systemic Toxicity ++ ++++ ++++ + + Gas in tissue ++ - ++++ - - Obvious portal of entry ++++ + ++++ - - DM ++++ + - - -

Complications::

Complications: - Overall mortality is up to 30% from: MOF Septic shock. Toxic shock syndrome (TSS) Contributing factors: * Old age. * DM. * Missed early diagnosis. * Trunkal invol. * Anorectal invol. * Late pres. * Failure after 1 st op. File TM, Tan JS . Group A strept. necrotizing fasciitis . Compr Ther. 2000;26 ( 2 ): 73-8.

Treatment:

Treatment D elay in diagnosis and treatment of necrotizing fasciitis increase s mortality McHenry CR, Piotrowski JJ, Petrinic D, Malangoni MA. Determinants of mortality in necrotizing soft tissue infections. Ann Surg 1995; 221:558–563. Aggressive ttt is needed even for suspected cases to reduce mortality .

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ABC. A ntibiotics as soon as possible ( aerobic and anaerobic bacteria ) Surgery: Aggressive resuscitation followed by aggressive debridement of all necrotic tissue . may need to be repeated ( careful daily postop inspection ). fasciotomies in extremities . Amputation for myonecrosis in limbs Postop use of unprocessed honey Stimulates epithelialization. Debrides Deodourizes wound Dehydrates Akram Rajiput, Waseem Abul Samad, Mortality in necrotizing fasciitis. J Ayub Med Coll Abbottabad 2008; 20(2)

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IV IG (UNDER STUDY) Hyperbaric oxygen therapy ( HBO ) Def. = use of 100 % O 2 at +++ pressure (3 AP). ↑ normal O 2 saturation in infected wounds by a thousand fold:  bacteriocidal effect.  ↑ PMN function  ↓ clostridial α toxin production.  enhanced wound healing . Mulla ZD. Hyperbaric oxygen in necrotizing fasciitis. Plast Reconstr Surg . Dec 2008;122 (6):1984-5.

Hyperbaric oxygen therapy :

Hyperbaric oxygen therapy Indications Contraindications Air embolism CO poisoning Necrotizing soft tissue infections Gas gangrene Crush injury Decompression sickness Enhancement of healing in selected wounds Osteomyelitis (refractory) Compromized skin grafts Untreated pneumothorax Asthma COPD Eustachian tube dysfunction Pregnancy Claustrophobia

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HBO cannot replace surgery . The best outcome is obtained using a combined approach of antibiotics, surgery, and HBO, when readily available .