Necrotising soft tissue infection

1. GANGRENE
BY IKWANG ARNOLD

2. OVERVIEW
• Gangrene refers to the death of body tissues
due to either lack of blood flow or serious
tissue infection. Gangrene commonly affects
the extremities i.e fingers ,toes and limbs. It
can aswell affect muscles.

3. What is gangrene?
Localized cell death by obstructed circulation
with superadded bacterial infection.

4. Etiology
 Lack of blood supply; blood provides oxygen and
nutrients to body cells aswell as immune systeme
components such as antibodies. Without a proper
blood supply, cells can’t survive and tissues may decay.
 Infection; if bacteria thrive unchecked for long,
infection can take over and cause tissues to die,
causing gangrene.
 Trauma; Traumatic wounds such as gunshot wounnds
and crushing injuries from car accidents can cause
bacteria to invade deep tissues within the body. When
such tissues are infected, they can cause gangrene to
occur.

5. Risk factors
Diabetes; High blood sugars can damage
blood vessels, decreasing blood flow to parts
of the body
Blood vessel disease; Hardened and narrowed
ateries[atherosclerosis] aswell as blood clots
can block blood flow to body parts
Severe injury or surgery; Any process that
causes trauma to your skin and underlying
tissues increases risk of developing gangrene

6. Smoking; It can lead to atherosclerosis thus
reducing blood supply to affected body tissues
Obesity; It is usually accomponied by vascular
diseases which may reduce blood flow to
affected body tissues.
Immunosuppression; The body’s ability to fight
off infections is impaired. Eg. In HIV,
chemotherapy.

7. TYPES OF GANGRENE
• Dry gangrene
• Dry gangrene is characterised by dry and
wrinkled skin ranging in color from brown to
purplish blue or black
• Dry gangrene may develop slowly
• It occurs most commonly in people who have
arterial blood vessel disease, such as
atheroslerosis or in diabetic people.

9. • Wet gangrene
• Gangrene is reffered to as wet if there is bacterial
infection in the affected tissue.
• Swelling, blistering and a wet appearance are
common features of wet gangrene.
• It may develop after a severe burn, frostbite or
injury.
• It oftenly occurs in people with diabetes who
unknowingly injure a toe or foot.
• Wet gangrene needs to be treated immediately
because it spreads quickly and can be fatal.

11. • Gas gangrene
• Gas gangrene typically affects deep muscle tissue.
• A bubbly appearance to your skin may become apparent,
and the affected skin may make a crackling sound when
you press on it because of the gas with in the tissue.
• Gas gangrene is most commonly caused by clostridium
perfrigens which develops in an injury or surgical site that
is depleted of blood supply.
• The bacteria produce toxins which release gas, hence the
name gas gangrene, which later causes tissue death.
• Gas gangrene can be life threatening.

13. • Internal gangrene
• Gangrene that affects one or more organs I
the body such as intestines, gallbladder or
intestines. This type occurs when blood flow
to internal organs is blocked. Eg, when
intestines buldge through a weakened area of
muscle in the abdomen[hernia] and become
twisted.
• Internal gangrene may cause fever and sever
pain. If left untreated, it can be fetal

14. • Fournier’s gangrene
• Fournier’s gangrene involves the genital
organs. Men are more oftenly affected, but
women can develop this type of gangrene
aswell.
• Fournier’s gangrene usually arises due to an
infection in the genital area or urinary tract.
• It causes genital pain, tenderness, redness and
swelling.

15. • Progressive bacterial synergistic gangrene[
Meleney’s gangrene]
• This rare type of gangrene typically occurs
after an operation, with

16. Diabetic gangrene
It is related to three factors:
 Trophic changes from peripheral neuropathy
 Ischaemia as a result of atheroma
(microangiopathy) .
 Low resistance to infection because of excess
sugar in the tissues.
Whatever the portal, any infection can spread
proximally with speed in subfascial planes.

17. • Treatment.
Diabetes control by diet and drugs.
Conservative approach if there is no major
arterial obstruction.
Antibiotic therapy
A rapid spread of infection requires
drainage by incision and the removal of
any obviously dead tissue.

18. Bedsores
• A bedsore is gangrene caused by local pressure.
• Five predisposing factors:
• Pressure, injury, anaemia, malnutrition and moisture.
• Appear in immobile patients and in those with debilitating
illness.
• Prophylactic measures:
• Avoidance of pressure over bony prominences by the use of
foam blocks or similar, regular turning, and nursing on
specially designed beds that reduce the pressure to the skin.
• A water bed or a ripple bed is sometimes desirable.
• Injury from wrinkled sheets and maceration of the skin by
sweat, urine or pus must be prevented by skilled nursing and
the use of an adhesive film dressing.

19. Frost bite

21. CLINICAL MANIFESTATION OF
GANGRENE
Skin discoloration; pale to blue, purple, black
or red.
Swelling or blister formation
Clear line between healthy and damaged skin
Sudden severe pain followed by a feeling of
numbness
A foul smelling discharge leaking from a sore
Skin that feels cool to touch

22. MANAGEMENT
• INVESTIGATIONS;
• CBC; Abnormally elevated white blood cell
count indicates the presence of an infection
• CT scan; can help t see any gas trapped under
skin and view internal organs
• Ultrasound doppler
• Arterogram; used to visualise arteries
• Fluid or tissue culture

23. Management
• Tissue that has been damaged by gangrene
cant be saved but steps can be taken to
prevent gangrene from progressing
• Complete history and physical examination
• Provide symptomatic treating like analgesia
• Do regular dressing.

24. • Surgery
• Perform debridment to remove dead tissue
inorder to prevent gangrene from spreading to
healty tissues
• If possible repair damaged blood vessels to
restore blood flow to affected areas
• If reconstructive surgery is needed, skin graft may
be used to repair damage to your skin
• A skin graft can only be done if adquete blood
supply is restored to the affected part

25. • In severe cases of gangrene, the affected body
extremeties may need to be amputated.
• Later, you may be fitted with a prosthesis
• Antibiotics
• These are used to treat gangrene that has
been infected.

26. • Hyperbaric oxygen therpy
Hyperbaric oxygen is delivered through a specially designed
chamber that contains oxygen under high pressure.
Hyperbaric oxygen has been shown in some studies to
improve wound healing, and it ensures that bacteria that
thrive only in an oxygen-free environment (anaerobic
bacteria) will be killed. However, this therapy is not
available in all medical centers.
People receiving hyperbaric oxygen therapy must be
monitored for symptoms of oxygen toxicity, such as profuse
sweating, difficulty breathing, and convulsions.

28. Complications
• Gangrene can be so severe leading to
amputation
• Infected gangrene can spread quickly to other
organs and can be fetal if untreated
• PREVENTION
• Proper care for diabetes
• Weight loss

29. • Avoid smoking
• Infection control

30. REFERENCES
• Bailey and Love’s Short Practice of Surgery
27th Ed
• Oxford Textbook of Surgery
• SRB’S Manual for surgery, 4th Ed

31. MWEBALE MUNO