Gas gangrene

it contains the basic knowledge of gangrene and how to treat it .

1. Gas gangrene Dr pooja pandey Junior resident -1 MS. general surgery Mims ,barabanki uttar pradesh

2. D efinition It is an infective gangrene caused by clostridial organisms involving mainly skeletal muscle as oedematous myonecrosis.

3. Organisms C. perfringens 80% , Clostridium welchii (perfringens): Gram-positive, central spore bearing, nonmotile, capsulated organisms, most common . b. Clostridium oedematiens . c. Clostridium septicum. d . Clostridium histolyticum. e. C . novyi, f. C . sordelli, g.C . fallax, h.C . bifermentans

4. Toxins Major Toxins α A-E Lecithinase , Necrotising, Haemolytic β B,C Necrotising ε B,D Permease Iota E Dermonecrotic 2. Minor Toxins δ B Haemolysin θ A-E Haemolysin , Cytolysin κ A-E Collagenase , Gelatinase, Necrotising λ B,D,E Protease µ A-E Hyaluronidase ν A-E Deoxyribonuclease , Leucocidin, Hemolytic, Necrotising

5. Pathogenesis  Lecithinase is important toxin which is haemolytic, membranolytic and necrotic causing extensive myositis. It splits lecithin into phosphocholine .  Haemolysin causes extensive haemolysis.  Hyaluronidase helps in rapid spread of gas gangrene.  Proteinase causes breaking down of proteins in an infected tissue

6. Risk Factors 1.Road traffic accidents- Deep wound Injuries to muscles. Crushed tissue Wound contaminated with dirt 2.Immunocompromised state like – HIV Chemotherapy and radiotherapy. 3.Diabetes 4.HTN 5.Smoking 7.Alcoholism 8,I.V drug abuse.

7. Clinical Features Incubation period is 1-2 days. Features of toxaemia, fever, tachycardia. 2 ) Wound is under tension with foul smelling discharge (sickly sweety / decaying apple odour). 3 ) Brown coloured skin due to haemolysis. 4 ) Crepitus can be felt. 5 ) Jaundice, oliguria . 6) Clostridium welchii can infect limbs, abdominal wall, appendix, gallbladder, common bile duct, intestine, uterus

8. Classification Fulminant type causes rapid progress and often death due to toxaemia, renal failure or liver failure or ARDS . B. Massive type involving whole of one limb containing fully dark coloured gas filled areas . C. Group type : Infection of one group of muscles, extensors of thigh, flexors of leg. D . Single muscle type affecting one single muscle. E . Subcutaneous type of gas gangrene involves only subcutaneous tissue

9. Fulminant type Subcutaneous type Group of muscles involved Single muscle type

10. Complications Septicaemia , toxaemia. 2 . Renal failure, liver failure. 3 . Circulatory failure 4. DIC 5 . secondary infection. 6 . Death.

11. Investigations X-ray shows gas in muscle plane or under the skin . 2) Liver function tests, blood urea, serum creatinine, TLC . 3) CT scan useful in chest or abdominal wounds. 4 ) Gram’s stain shows Gram-positive bacilli. 5 ) Robertson’s cooked meat media is used which causes meat to turn pink with sour smell and acid reaction.

12. Air present indicates Gas gangrene in lower limb

13. Treatment Injection benzyl penicillin 20 lacs 4th hourly + Injection metronidazole 500 mg 8th hourly + Injection aminoglycosides or third generation cephalosporins . b. Fresh blood transfusion. c . Polyvalent antiserum 25,000 units d . Hyperbaric oxygen . e. All dead tissues are excised and debridement is done.

14. Treatment f . Rehydration and maintaining optimum urine output(0.5ml/kg/hour ). g. Electrolyte management. h. In severe cases amputation has to be done as a life-saving procedure j . Often ventilator support is required. k. Hypotension in gas gangrene is treated with whole blood transfusion.

15. SURGICAL CARE Fasciotomy for compartment syndrome –not be delayed in patients with extremity involvement. For necrotic tissue- daily debridement needed. Life saving procedure- amputation of the extremity. In case of abdominal involvement – excision of the body wall musculature. Hysterectomy is needed in case of uterine gas gangrene following septic abortion.

16. Multiple choice question Q1)When the Clostridium perfringes is introduced in the body ,what type of gangrene will result a)Wet gangrene b)Fournier’s gangrene c)Dry gangrene d)Gas gangrene. Q2) Regarding gas gangrene one of the following is correct: A. It is due to Clostridium Botulinum infection B. Clostridial species are gram—negative spore forming anaerobes C. The clinical features are due to the release of protein endotoxin D. Gas is invariably present in the muscle compartments

17. Scenario based questions A 55 year female patient came in ER with the complaints of RTA 1 day back and presented with fever ,pain and heaviness in left leg associated with multiple open wounds and swelling since then. She was treated in PHC and from there she was referred to the T ertiary Centre for further management. O/E- temp-100 degree F,B.P100/70 mm of Hg, PR-110/min,RR-24/min . O/I- left limb was swollen , bronze discoloration of the surrounding skin , and discharge was present which was very offensive in nature , few wounds were necrosed too. a)What is the differential diagnosis ? b)Write the work up plan to reach the definitive diagnosis? c)How will you manage the case ?