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Arthritis

Compartment syndrome and ischaemic limb

Acute compartment syndrome and clinical signs of limb vascular compromise

18 questions 2 source pages

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18 questions
Q1Define compartment syndrome and give its causes.▸
  • Impaired perfusion in an enclosed fascio-osseous compartment due to increased compartmental pressure
  • Intracompartmental: haematoma (fracture, bleeding disorder), muscle oedema (crush injury)
  • Extracompartmental: tight dressing or cast preventing the compartment from expanding
Q2How is compartment syndrome diagnosed clinically?▸
  • It is a clinical diagnosis
  • Early: pain out of proportion, pain on stretching the compartment
  • Late: the 5 Ps
Q3When and how is compartment pressure measured?▸
  • In unconscious patients or children
  • Absolute pressure 30 mmHg, or measured pressure minus DBP <30 mmHg
  • Measure all compartments within 5 cm of the fracture
  • Commercial kit or the Whiteside method
Q4What is the timing and incision for fasciotomy?▸
  • <8 hours to prevent irreversible muscle ischaemia
  • Delayed fasciotomy is not advisable - high infection rate
  • Expansile longitudinal incision
Q5What are the principles of fasciotomy?▸
  • Longitudinal extensile approach; release all compartments
  • Avoid injury to the NV bundle
  • Assess muscle viability - colour, contraction, consistency
  • Debridement and delayed closure
Q6How many compartments are in each region?▸
  • Arm 2, forearm 3, thigh 3, leg 4
  • Hand 10, foot 9
Q7What does this clinical photo show and what is the concern?▸
  • Patches of mottled-looking skin along the right upper limb
  • Serosanguinous discharge over the dorsum of the hand
  • Early formation of haemorrhagic blisters
  • Worry: necrotising fasciitis (NF)
Q8What history is important in suspected necrotising fasciitis?▸
  • Timing
  • Any previous treatment
Q9How is the patient with necrotising fasciitis and septic shock resuscitated?▸
  • Resuscitate with the sepsis 6 protocol
  • Inform ICU for inotropic support
Q10What antibiotics are used for necrotising fasciitis per the IMPACT guidelines?▸
  • Polymicrobial: imipenem
  • Monomicrobial: clinda + linezolid
  • Sea (marine): fluoro + amoxi
  • +/- IVIG for STSS
Q11What is the role of the LRINEC score in NF?▸
  • Adjunct if there is diagnostic doubt
  • Parameters: WCC, Hb, Cr, Na, Glu, CRP
  • >8 is strongly predictive
  • Finger probe test if diagnostic doubt
Q12What are the operative principles in necrotising fasciitis?▸
  • Save life, then limb, infection control
  • Urgent surgery for dermatofasciectomy +/- amputation
  • Longitudinal extensile incision
Q13What is the firebreak theory for debridement in necrotising fasciitis?▸
  • Divide skin and fascia into 3 zones
  • Skin and subcutaneous tissue: excise zone I and II, leave III
  • Fascia: excise zone I, II and III
Q14When is amputation considered in necrotising fasciitis?▸
  • Systemic factors: poor premorbid, refractory shock (need >1 inotropes)
  • Local factors: large area of myonecrosis, extensive involvement especially the plantar region, significant PVD
  • Reference: JBJS Tang 2001 HKU
Q15What other adjunctive therapy is mentioned for necrotising fasciitis?▸
  • Hyperbaric oxygen
Q16What are the four types of necrotising fasciitis infection?▸
  • I: polymicrobial - at least one anaerobe +/- facultative anaerobes (enterobacteriaceae, non-group A strep)
  • II: monomicrobial - group A strep
  • III: marine vibrio
  • IV: MRSA
Q17Describe the pathophysiology of necrotising fasciitis.▸
  • Stage 1: spread along fascia
  • Stage 2: thrombosis of perforators
  • Stage 3: extensive tissue necrosis
Q18What are the predictors of mortality in upper limb NF?▸
  • Shock
  • Involvement of elbow or above
  • Platelet count <150
  • Creatinine >=1.5x normal
  • Deranged LFT
  • Overall mortality ~27%
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