Q. Discuss gangrene? OCT/NOV 2010,PAPER 1

Sub headings:

• Definition

• Types

• Clinical features

• Investigations

• Treatment

Gangrene :

• Definition:

• It is macroscopic death of tissue in situ with or without putrefaction.

OTHER TERMS:

• CRITICAL LIMB ISCHEMIA:• It is persistently recurring ischemic rest pain for 2 weeks or

ulceration or gangrene of the foot or toes with an ankle systolic <50 mm hg or toe systolic <30 mm hg

• Pre gangrene :• It is changes in tissue which indicate that blood supply is

inadequate to keep the tissues alive and presents with rest pain ,colour changes,oedema,hyperaesthesia with or without ischemic ulceration.

OTHER TERMS

• Gangrenous inflammation:• Primary inflammation provoked by virulent

bacteria resulting in massive tissue necrosis.

• E.g. :

gangrene lung,

gangrenous appendicitis,and

noma(cancrum oris)

Types of gangrene:

• Dry

• Wet

• Gas gangrene

Dry vs wet gangrene

Feature Dry gangrene Wet gangrene

Site Commonly limbs Common in bowel

Mechanisms Arterial occlusion Venous occlusion

Macroscopy Dry,shrunken,black Moist,soft,swollen,rotten,dark

Putrefaction Limited marked

Demarcation present no

Bacteria Fail to survive numerous

Prognosis better poor

Gas gangrene

• A special form of wet gangrene caused by gas forming clostridia which gain entry into tissues through open contaminated wounds ,especially in muscles or as complication of operation on colon which normally contains clostridia.

• Clostridia produce various toxins produce necrosis and oedema.

Causes of gangrene

• Secondary to arterial occlusion:

arteriosclerosis,diabetes,TAO,raynauds,ergots

• Infective:

boil,carbuncle,gas gangrene,fourniers ,cancrum oris• Traumatic:

Direct,indirect• Physical :

burns,scalds,frost bite,chemicals,irradiation,electricity• Venous gangrene

INVESTIGATIONS:

• Hb%

• Blood sugar

• Arterial doppler

• Angiogram(seldinger)

• u/s abdomen-status of aorta

Treatment:

• Limb saving methods

• Life saving procedures

Limb saving methods

• Drugs:Antibiotics,vasodilators,pentoxyphylline,praxilene,dipyridamole,small

dose of aspirin,ticlopidine

• Care of feet and toes: Parts kept dry

Avoid injury

Proper foot wear

Pain relief

Nutrition supplementation

Pressure areas protected

Pus drained

Limb saving methods

• Cause treated• Diabetes controlled• Surgeries to improve limb perfusion:

Lumbar sympathectomy,omentoplasty

Profundoplasty,femoropoliteal thrombectomy,or endarterectomy,arterial graft bypass done according to need.

Life saving procedures

• Amputations may have to be done occasionally.• Level of amputation decided by skin

changes,temperature,line of demarcation,doppler study.

• B/K amputation• a/k amputation• Ray amputation• Gritti stokes amputation