Transcript gas gangrene

GAS GANGRENE
Dr. Ehsanur Reza Shovan
• It is a rapidly progressive, potentially fatal condition
characterized by widespread necrosis of the
muscles and subsequent soft-tissue destruction.
• This is a dreaded consequence of inadequately
treated missile wounds, crushing injuries and highvoltage electrical injuries.
Causative agent
• Clostribium species – spore forming, Gram +ve
c.septicum
c.novyi
c. Perfringens
(mostly)
• They are present in the soil
and have also been
isolated from the human
gastrointestinal tract and
female genital tract.
• Non-clostridial gasproducing organisms such
as coliforms have also
been isolated in 60–85% of
cases of gas gangrene.
vegetative
cells multiply
Spores
germinate
Anaerobic
environment
Carbohydrates
Fermentation
PATHOGENESIS
Incubation period is
Gas production
In tissues
1-7 days
Toxemia and
death
Distension of
tissues
Interfering
Blood supply
Ischemia/
gangrene
Pathogenesis
- Bacteria
enters the
broken skin or
wound
- Spores
are
produced
- The toxins
(lecithinase)
and enzyme
are produced
- The
bacteria are
grow and ferment
the muscle
carbohydrate
- The bacteria
present in
circulation
system
the anaerobic
tissue present
Examples of enzyme:
colagenases, proteases
and lipases
- These enzymes will
kill other host cell and
extend the anaerobic
environment
- Produce gases (nitrogen,
hydrogen sulphide and
carbon dioxide)
- Crepitant tissue
( destroyed tissue)
Epidemiology
– The persons at risk those with Diabetes Mellitus,
blood vessel disease and colon cancer
– Contact with contaminated cloth and other
foreign material
– Trauma or recent surgical wound
Symptoms
•
•
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High fever
Shock
Massive tissue destruction
Blackening of skin
Severe pain around a skin of wound
Blisters with gas bubbles form near the
infected area,
• the heartbeat and breathing become
rapid.
Presentation
Crepitation in tissues,
sickly sweet odor discharge,
rapidly progressing necrosis,
fever, hemolysis, toxemia,
shock,
renal failure, and death
Lab. Investigations
Culture and sensitivity
Storming fermentation
Lecithinase test
G
A
S
I
N
S
O
F
T
T
I
S
S
U
E
G
A
S
I
N
U
T
E
R
U
S
G
A
S
I
N
U
T
E
R
U
S
G
A
S
I
N
U
T
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R
U
S
Prevention
• Cleaning the wound
• Avoid the contaminated material
• improve circulation in
patients with poor circulation
• antitoxin
Prevention
(1) Do a thorough wound toilet.
(2) In high risk wounds give the patient
penicillin 1.5 megaunits 4 hourly,
or tetracycline
Treatment
• High doses of antibiotic : Penicillin
• The dead tissue is removed or limbs are
amputated
• No vaccine
10 megaunits of benzyl penicillin daily for 5
days as four 6 hourly doses.
Or
Tetracycline 0.5 g intravenously
or 1 g orally every 6 hours.
Clostridia not sensitive to metronidazole,
some other anaerobic bacteria are, so give
it.
EXPLORATION
Do this in a septic theatre,
or even in the out-patient department,
and not where clean cases go for operation.
AMPUTATION
Amputate under a tourniquet
Close the stump by delayed
primary suture
Myonecrosis of right leg
Myonecrosis of left foot
Stump of above knee amputation
• Patients should be admitted to ICU and
treated aggressively with careful monitoring.
• The role of HBO is not as clear as in
necrotising fasciitis but it is recommended in
severe cases if the facilities are available.
– increases the normal oxygen saturation in the
infected wounds by 1000-fold leading to
• Bacteriocidal effect,
• Improves neutrophil function,
• Enhanced wound healing