MYONECROSIS
OR GAS GANGRENE
Dr. Mansoor KhanResident Surgery, MBBS, FCPS-I
Khyber Teaching Hospital, Peshawar
BACTERIA
GRAM (+) GRAM (-)
AEROBIC ANAEROBIC AEROBIC ANAEROBIC
CLOSTRIDIUM
CLOSTRIDIUM PERFRINGENS
Clostridium perfringens A is important in human
Cellulitis: Infection with gas formationin the soft tissue.
Fasciitis or suppurative myositis:Infection and gas in the muscle planes.
Myonecrosis:or gas gangrene:a life-threatening disease.
Range of infections
Spores germinate
Distension oftissues
InterferingBlood supply
Ischemia/gangrene
Toxemia anddeath
vegetative cells multiply
Spores germinate
CarbohydratesFermentation
Gas productionIn tissues
PATHOGENESISIncubation period is
1-7 days
Crepitation in tissues,foul smelling discharge,
rapidly progressing necrosis,fever, hemolysis, toxemia, shock,
renal failure, and death
Presentation
Culture and sensitivity
Storming fermentation
Lecithinase test
Lab. Investigations
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
E
R
U
S
(1) Do a thorough wound toilet.(2) In high risk wounds give the patient penicillin 1.5 megaunits 4 hourly, or tetracycline
Prevention
Isolate the patient from other surgical patients
10 megaunits of benzyl penicillin daily for 5 days as
four 6 hourly doses.
OrTetracycline 0.5 g
intravenously or 1 g orally every 6 hours.
Clostridia not sensitive to metronidazole, some other anaerobic bacteria are, so give it.
Do this in a septic theatre, or even in the out-patient department,
and not where clean cases go for operation.
EXPLORATION
AMPUTATION
Amputate under a tourniquet Close the stump by delayedprimary suture
Fournier,s gangrene
Myonecrosis of right leg
Myonecrosis of left foot
Stump of above knee amputation
Dr. Mohammad ZarinFCPS, MRCS (Eng), FMASAssistant Prof. SCW
A disease caused by Clostridium tetani characterized by local or generalized spasmodic contraction of muscles
Gram positive, anaerobic, spore forming rods
Clostridium tetani
Contamination of devitalized tissue with the spores, germination of the spores,
release of tetanospasmin, the toxin reaches CNS by retrograde axonal transport or via the bloodstream
the toxin is fixed to gangliosides in spinal cord or brainstem and exerts its actions
TETANOSPASMIN
Inhibits release of an inhibitory mediator
(e.g., GABA or glycine) which acts on
postsynaptic spinal neurons
(causing spastic paralysis).
Localized tetanus
Confined to the musculature of
primary site of infection
Neonatal tetanus
(infection of the umbilical wound):
mortality > 90%, and developmental defects are present in survivors.
Generalized tetanus first the area of injury, then the muscles of the jaw (trismus or lockjaw risus sardonicus.
Other voluntary muscles become involved gradually, resulting in generalized tonic spasms (opistotonus).
Death usually results from interference with respiration. The mortality rate of generalized tetanus: ~50%.
Prevention is much more important than treatment:
1. Active immunization with toxoid.
‘Booster shot’ for previously immunized individuals. This may be accompanied by antitoxin injected into a different area of the body.
2. Proper care of wounds. Surgical débridement to remove
the necrotic tissue.
3. Prophylactic use of antitoxin.
4. Antibiotic treatment. Metronidazole
*Patients with symptoms of tetanus should receive muscle relaxants, sedation and assisted ventilation.
Prevention and treatment
Prophylaxis
THANKS