Gangrene Flashcards
What is gangrene?
Tissue necrosis secondary to critical ischaemia
Gangrene can lead to severe complications if not treated promptly.
What are the two main types of gangrene?
- Dry
- Wet
Each type has distinct causes and characteristics.
What causes dry gangrene?
Mummification of the affected tissue WITHOUT infection due to underlying arterial occlusion
Conditions include PAD, DM, and vasculitis.
What are the characteristics of dry gangrene?
Progresses slowly, area appears dry/shrivelled/dark brown or black
This slow progression can sometimes allow for intervention.
What causes wet gangrene?
Tissue necrosis WITH an infective cause leading to liquefaction due to blockage of venous outflow/lymphatics
Conditions include CLI, surgical wounds, immunosuppression, and severe burns.
What are the characteristics of wet gangrene?
Progressive quickly, appears swollen/blistered/emits foul smell + often affects highly vascular areas/skin folds
Rapid progression makes it more dangerous than dry gangrene.
What is gas gangrene?
A subtype of wet gangrene caused by gas production within tissue often due to Clostridium perfringens
Commonly occurs when wounds are contaminated with soil or fecal matter.
What are the conditions associated with gas gangrene?
Contaminated wounds, surgical procedures involving GI or biliary system
Immediate medical attention is crucial.
What characterizes Fournier’s gangrene?
Polymicrobial infection located in the genitalia or perineum
This condition requires urgent medical intervention.
What is necrotising fasciitis?
A rapidly progressing infection involving subcutaneous tissues and fascia caused by Group A Streptococcus
It results in extensive necrosis.
What is the pathophysiology of gangrene?
- Reduced blood supply –> Hypoxia + ischaemia –> cell dysfunction and death
- Anaerobic metabolism –> lactic acid production –> impair cell function
- Tissue necrosis –> good environment for bacteria
- Bacterial infection –> rapid replication + toxin release
- Toxin production –> haemolysis + tissue destruction
- Sepsis –> multi-organ failure –> death
Understanding the pathophysiology helps in effective treatment.
What are the local symptoms of gangrene?
- Pain
- Swelling, tenderness
- Red/black/brown color
- Blistering/foul smell
- Sensory changes/loss
- Tissue loss
Local symptoms can indicate the severity of the condition.
What are the systemic symptoms of gangrene?
- Malaise, fever
- Hypotension –> Septic shock
- Multisystem involvement –> SIRS
Systemic symptoms can signify a more severe infection.
What imaging techniques are used for investigating gangrene?
- XR (gas deposits or PAD calcification)
- CT
- MRI
- Duplex USS (reduced blood flow)
Imaging helps determine the extent and type of gangrene.
What blood tests are useful in diagnosing gangrene?
- Blood culture (sepsis - guide antibiotic treatment)
- FBC/U&Es/LFTs (sepsis)
- CRP
- ESR (infection)
Blood tests are essential for assessing infection and guiding treatment.
What are the differential diagnoses for gangrene?
- Cellulitis
- Necrotising Fasciitis
- PAD
Differentiating these conditions is critical for appropriate management.
What is the medical treatment for gangrene?
Antibiotic therapy - broad spectrum then use culture specific abx
Prompt antibiotic treatment is crucial in controlling infection.
What surgical treatments are available for gangrene?
- Debridement
- Amputation
Surgical intervention may be necessary to prevent further tissue loss.
What is the purpose of hyperbaric chamber treatment for gangrene?
To improve O2 delivery to tissues
This can enhance healing and combat infection.
