Compartment Syndrome

Question 1

Pathophysiology

Answer 1

• Inc intramuscular pressure in confined compartment –> tissue ischemia and anoxic tissue injury to muscles, nerve, etc (myocyte necrosis –> release osmotically active proteins –> water/edema –> further dec arterial blood flow –> worse ischemia) –> contractures
• Damage can occur in 6 hrs

Question 2

What are the two most common compartments?

Answer 2

• Lower leg
  
  • Anterior compartment - anterior tibial artery and deep peroneal nerve for toe dorsiflexion and dorsal sensation
  • Lateral compartment - superficial peroneal nerve; eversion of foot and lateral sensation
  • Superficial posterior compartment - sural nerve; ankle plantar flexion and lateral heel sensation
  • Deep posterior compartment - posterior tibial artery and tibial nerve for toe plantar flexion and sole sensation
• Forearm
  
  • Volar - flexors, ulnar and radial arteries, ulnar and median nerves
  • Dorsal - finger extensor muscles
  • Lateral Mobile Wad - wrist extensor muscles

Question 3

Internal v External Causes

Answer 3

• Internal - bleeding, capilary leak from trauma, burns, seizures
• External - constrictive (cast, splint, lying on limb for extended period)

Question 4

5 Ps

Answer 4

Pain (out of proportion and w/ passive motion),

paresthesias (in nerve distribution),

paresis (weakness in muscles of those compartments),

pallor (pale),

pulselessness (last thing to happen)

Question 5

Dx

Answer 5

• Check compartment pressure (needle manometer) - insert needle, inject saline, equilibrate and then gives pressure reading (repeat until consistent readings)
• If > 30 mmHg = compartment syndrome

Question 6

Tx

Answer 6

• Fasciotomy (early decompression w/in 6 hrs is best)
• Elevate limb and treat hypotension in meantime
• Remove cast or other external forces