gas gangrene

Question 1

gas gangreen overview

Answer 1

clostridium genus encompasses > 60 species
range from gut microflora , female genitalia, oral mucoso to human pathogens

not all clostridia are toxigenic
wide spread in nature
soil feces sewage and marine sediments

clostridial perfingens and clostridial septicum
-aggressive necrotizing infections attributed to multiple toxins

C perfringens produce epislion toxin
most lethal clostridial toxin and biological warfare
- organ edema and hemorrhage

incubation period
following traumatic gas gangrene
6 hours to < 4 days

Question 2

gas gangrene clostridial myonecrosis causes

Answer 2

clostridial perfingens myonecrosis
- fulminant gram-positive bacterial infections

development of gas gangrene
anaerobic environment
wound contamination

predisposing conditions

crush-type injury, laceration of large/medium arteries, and open fractures

• bacterial spore contamination

abdominal gas gangrene
follows penetrating injuries
knife or GSW

compromise intestinal integrity
leakage of bowel contents

cutaneous gas gangrene
caused by
C perfringens, c . novi and c sordelii:

injection of black tar heroin

Question 3

gas gangrene oraganism

Answer 3

anerobic vs aerotolerant
C perfringens and C novyi
sufficient trauma
interrupt blood supply
optimizes anaerobic environment

c septicum and c tertium:
seed in normal tissue from GI lesion

Toxin release:
alpha-toxin induces occlusion of blood vessels
marked tissue destruction

Question 4

gas gangrene clinical findings

Answer 4

septic appearance
sudden onset of excruciating pain at affected site
infected site develop foul smelling
serosanguionous discharge and gas bubles

brawny edema and induration develop
cutaneous blisters
continue blueish to maroon-colored fluid
rapid progression of skin sloughing

cardiovascular collapse and organ failure
due to bacterial toxins
reduce SVR, increase CO
warm shock and gram-negative sepsis

profound hypotension and sudden reduction of co

bacteremia
mortality > 50%
majority end in death

Question 5

gas gangreen diagnosis

Answer 5

infection begins at sight of trauma
gas intissue
rapid progression

imagining
CT and MRI
determine whether the infection is localized or spreading

invasive technique
needle aspiration or punch biopsy
provide etiologic diagnosis

Surgical exploration:
required for gram staining and biopsy
definitive diagnosis
gram-positive rods
absence of inflammatory cells
widespread soft tissue necrosis

Question 6

treatment plan gas gangrene

Answer 6

immediate surgical debridement
radical amputation
devitalized tissue resected back to healthy tissue
delayed closure 5-6 days

antibiotic plan ;
penicillin G plus clindamycin
PCN: allergies - cefoxitin plus clindamycin
C. Tertium alternative regimine
- vancomycin plus flagyl

following surgical exploration and debridement
hyperbaric oxygen therapy
controversial