flesh eating bacteria

[stabilo]

Necrotizing fasciitis

What is it?

• Bacterial infection
  Attacks soft tissue & fascia
  Sparing underlying muscles
  Uncommon
  May affect any part of the body

organism
Type I, or polymicrobial NF, usually occurs after trauma or surgery: This form may initially be mistaken for a simple wound cellulitis.
Type II, or group A streptococcal NF, is the so-called flesh-eating bacterial infection
Type III NF, or clostridial myonecrosis, is gas gangrene. This skeletal muscle infection may be associated with recent surgery or trauma

Etiology: 
Blunt or penetrating trauma
Surgery
IV drug use
Childbirth
Burns

Predisposing factors
Can happen to anyone...young, old, adult, child, any race, any size, healthy or not.
RISK…
Immunosuppression
Advancing age
Chronic renal failure
Peripheral vascular disease
Diabetes Mellitus 
Intravenous drug user
Obesity

Pathophysiology
Enters the body & quickly multiplies 
Produces toxins & enzymes that destroy the subcutaneous tissue & fascia
Tissues become gangrenous
Bacteria can hide itself from the body's innate immune system, allowing it to spread rapidly

Symptoms (early findings)
Begin with constitutional symptoms of fever
Pain
Erythema
Tachycardia
Swelling
Nerve affected à skin anesthesia

Symptoms (Late findings)
Extreme pain
Skin discoloration (purple or black)
Blistering
Hemorrhagic bullae
Crepitus on palpation
Severe sepsis or SIRS
MODS

photos of necrotizing fasciitis:

source: http://www.emedicine.com


source: webs.wichita.edu/.../lecture17/lecture17.html

Diagnosis is still primarily clinical & high index of suspicion


source: en.wikibooks.org/.../Necrotizing_fasciitis
56 year old man with acute leukemia and necrotizing fasciitis
note the gas on plain films (its absence does not rule out the disease)

Management
Immediate resuscitation
Broad spectrum IV antibiotics
Aggressive surgical debridement

Following debridement
Sterile dressing
Wound coverage
Split thickness skin grafting
Tissue transfer


split skin graft
source: http://www.vanceairscoop.com

Reference:
Hasham S, Matteucci P, Stanley PRW, Necrotising fasciitis, BMJ 330(7495) 830-833
Maynor M, Necrotizing Fasciitis, http://www.emedicine.com/EMERG/topic332.htm

Questions:
Is there a way to detect the problem earlier?
Can we differentiate cellulitis from necrotizing fasciitis in early course of the disease?
Can necrotizing fasciitis be prevented?
Can hyperbaric oxygen play a role in the management of this problem?

Let’s discuss them together
please inform me if there is any problem with this post
thanks 
[/list]

[Admin]

Necrotising fasciitis on appearance is more patchy and less uniform compared to cellulitis. Other than that, I am not sure how to differentiate between the two based on clinical presentations. Any opinions?

[shinzui]

so if a 25year old, previously healthy man, comes in with a painful erythematous right calf and he's looking real sick. Clinically you suspect he's having a nec fac, what would your first steps of management be? and what antibiotic would you start him on? why?

[Admin]

so if a 25year old, previously healthy man, comes in with a painful erythematous right calf and he's looking real sick. Clinically you suspect he's having a nec fac, what would your first steps of management be? and what antibiotic would you start him on? why?

NF is mostly caused by group A streptococus. Therefore intravenous antibiotics targeting gram possitive cocci like amoxillin will be appropriate.

[stabilo]

Suspected necrotizing fasciitis

- Take blood for FBC, BUN, CRP, blood culture, wound swab, Plain X ray
- IV access, fluid resuscitation according to clinical state
- IV antibiotics (as most cases are polymicrobial, empirical broad spectrum antibiotic should be used- cover Gram +ve cocci, facultative anaerobic Gram –ve rods and anaerobics- combination of Penicillin, gentamicin [check renal function prior to administration], metronidazole/ clindamycin)
- Subsequent antibiotic will be guided by result of culture and sensitivity
- Pain relief
- Prepare whole blood and clotting products for the patient before surgery is essential
- Aggressive surgical debridement (without delay)
- Excise all non-viable tissue
- Further surgical exploration 24 to 48 hours later (ensure infectious process not extended)
- Repeated debridement may be necessary until the infection has been controlled adequately

[shinzui]

Well said. Penicillin is the broad-spec of choice simply cos it's cheap and gives a good blanket I suppose.

SO what guidelines do you follow to estimate/ manage fluid resuscitation? HOw do you determine if adequate resuscitation is achieved? IF the pt were to have immediate surgery, how would you determine maintenance IV fluid? (this is relevant to 1st Q)

What would you prescribe for pain relief?

[stabilo]

Patient should be resuscitated according to his or her clinical state

Assessment of volume status:
1. Cold peripheries (vasoconstriction)
2. Increased capillary refill time
3. Tachycardia (often the first measurable sign)
4. Increase respiratory rate
5. Metabolic acidosis (anabolic metabolism of inadequately perfused cells, producing lactic acidosis)
6. Hypotension  (late sign)
7. Reduced urine output
8. Reduced conscious level

Standard, large (14 to 16 gauge) peripheral IV catheters are adequate for most fluid resuscitation
If patient is in shock, infuse 1 L of crystalloid (0.9%NS) in 10 to 15 min
(Crystalloid resuscitates both intravascular and interstitial space and promotes urine output)
Patient with intravenous volume depletion without shock can receive 500ml/h infusion of crystalloid
Reassess patient’s clinical state
continue infusion if necessary

Adequate end organ perfusion is best indicated by urine output of >0.5 to 1 ml/kg/hr
Heart rate, mental status and capillary refill may be unreliable


references:
fluid resuscitation, http://www.surgicalcriticalcare.net/Guidelines/fluid_resuscitation.pdf
Acute care, volume resuscitation, http://www.studentbmj.com/issues/04/04/education/144.php
intravenous resuscitation, http://www.merck.com/mmpe/sec06/ch067/ch067c.html


correct me if i am wrong. keen to learn more. thanks in advance 

[matthardy]

Over the last several years, you've heard stories about a flesh-eating bacteria that can dissolve muscles and skin, leading to amputations and even death. This supposedly new disease may be caused by taking non-steroidal anti inflammatory drugs such as ibuprofin, aspirin, Motrin and Tolectin when you are infected with a beta strep germ. A report in the New Zealand Medical Journal showed that five of seven cases of flesh-eating bacteria occurred in people who took these pain medicines.

When you get an infection, certain white blood cells called macrophages produce a chemical called tumor necrosis factor, which travels to your brain and causes your body to produce prostaglandins that cause fever and shut off tumor necrosis factor. Aspirin and nonsteroidal anti inflammatory drugs block the production of prostaglandins, causing the white blood cells to keep on producing tumor necrosis factor. This can allow the bacteria to spread through the body, producing toxins which dissolve tissue and even cause shock and death.

[amanda]

what do you mean by beta strep germ? is it the strep throat infection? how does it diagnose? and what are the significant way to prevent this kind of infection?

[neodesigns]

This is just one more reason why you should always wash your hands and keep things clean!

[justinbarby]

Well I have heard stories about a flesh-eating bacteria that can dissolve muscles and skin, leading to amputations and even death. This supposedly new disease may be caused by taking non-steroidal anti inflammatory drugs such as ibuprofin, aspirin, Motrin and Tolectin when you are infected with a beta strep germ.

[naturalimmunity]

It sounds like a relatively new disease

[ralssonjack]

This allegedly new ache may be acquired by demography non-steroidal anti anarchic drugs such as ibuprofin, aspirin, Motrin and Tolectin if you are adulterated with a beta strep germ.