Acute Compartment Syndrome Flashcards
what are the clinical effects of an ischaemic problem (let’s say in the forearm after a fracture)?
irreversible contractures affecting the flexor compartment of the arm following forearm fractures This was associated with massive venous stasis with simultaneous arterial insufficiency and tight bandages
what is anterior tibial syndrome?
acute inflammatory condition after leg injury. This included: - swelling - pain - erythema this was due to high tissue pressures causing ischaemia
what are the main things to remember about acute compartment syndrome?
limb threatening should always have a high index of suspicion for ACS Key pathology = ISCHAEMIA
what is the aetiology of acute compartment sysndrome? name at least 4
- occurs after trauma (70%) - can be aggrevated by tight bandaging/cast - can be soft tissue trauma alone - can be seen in vascular reperfusion of acutely ischaemic limb - burns (circumferential eschar) - crush injuries - haemorrhage (10% on anti-coagulants or have bleeding disorders) - drug injection - post lithotomy positioning - acute ad chronic exertional
how does compartment syndrome develop?
This happens when intramuscular pressure is elevated insufficiently to reduce nutritional blood flow significantly to tissues within the involved compartment. or It is an ischaemic injury FROM vascular flow impediment BY high interstitial pressures
what are the at risk sites for compartment syndrome? high to low risk order
LOWER LEG forearm hand foot thigh
where can compartment syndrome occur?
in any muscle compartment bounded by inelastic walls - sheets of fascia and bone
why does compartment syndrome occur in muscle with inelastic walls?
there is some (limited) room for expansion after injury - when this becomes full then pressure rises exponentially this causes blood vessels to be compresses causing decrease in blood flow. this means that eventually the (muscle) tissue becomes ischaemic.
what types of vessels are compressed first to last in acute compartment syndrome?
those with lowest pressure are compressed first - veins (5-10 mmhg) - capillaries (15-20mmhg) - arterioles - main arteries in compartment (120/80mmhg) note that if you suspect compartment syndrome in leg however you can feel pulse at foot that doesn’t mean that the patient doesn’t have ACS because it takes a lot of pressure to occlude the main artery
what does it mean if the foot is pink warm and has a pulse however you suspect that the leg has Acute compartment syndrome?
if you suspect compartment syndrome in leg however you can feel pulse at foot that doesn’t mean that the patient doesn’t have ACS because it takes a lot of pressure to occlude the main artery
what is the progression in tissue damage in acute compartment syndrome? why is this good?
- nerve - muscle - artery - vein - skin nerve and muscle are easiest to regenerate provided there are viable sarcomeres left to regenerate and viable neurones to repair
what is needed for the regeneration of muscle and nerves?
nerve and muscle are easiest to regenerate provided there are viable sarcomeres left to regenerate muscle and viable neurones to regenerate nerves for this to be successful, treatment is vital in the early stages
what is tissue damage proportional to? give examples
it’s proportional to pressure x time at which pressure is elevated greater than 30mmHg for 8 hours = permanent damage higher pressures for shorter periods can also produce permanent damage
who is most likely to develop acute compartment sysndrome form trauma?
who is most likely to develop acute compartment sysndrome form no trauma?
in trauma patients for acute compartment syndrome, what is teh epidemiology for those with fractures vs those without fractures?
what fractures are more common in young adults vs children?
lower leg is more common in adults with tibial being most common
in children its mainly forearm and supracondylar injuries
both adults and children get forearm fractures though
what are the main causes of compartment syndrome in patients with no tracuma?
usually due to prolonged immobility
also seen in patients who have been on long term anti-coagulants
Is Acute compartment syndrome more frequent in hig or low energy injuries?
its more common in low energy tibial fractures because fascial compartments are more likely to be intact.
this means we are more liable to get the compression
can acute compartment occur in open fractures?
yes because compartments will often remain intact in open fractures.
how do we diagnose acute compartment syndrome?
mostly clinical and dependant on symptoms and signs seen
what are the classical findings in acute compartment syndrome?
The 5 P:
- Pain (particularly on passive movent)
- Paraesthesiae - site depends on compartment
- Paresis or paralysis
- Pallor - variable
- Pulselessness - very late
if there is damage wo your shin and you get parasthesiae, where are you most likely goint to feel it?
in the first webspace of foot
out of the 5 Ps in clinical diagnosis of acute compartment syndrome, what are the main Ps we are interested in?
how can we clinically and objectively measure acute compartment syndrome?
we can check the pressure of the compartment through stryker slit cathater
we are interested in delta pressure
what should compartment pressure be normally? what happens if its out of range?
how is it calculated?
normal is below 30mmHg
- above this, there is threshold for fasciotomy
its the difference between the patients diastolic blood pressure and the pressure measured in the compartment
why are people suspected with/have compartement sundrome constantly monitered?
those who are suspected should be monitered before they have symptoms and if they reach above 30mmHg in pressure should have fasciotomy - this means tehy have no long term effects.
if not monitered and we wait for symptoms then they will have significant long term effects
apart from patients with suspected acute compartment syndrome, what pressures should we also measure in other patients?
polytrauma
head injury
children
high energy fractures
crush
burns
arterial injuries post repair
overdose
if you were an FY1 on call, what would you do if a patient arrives and compartment syndrome is suspected? what is your thought process?
release bandages to allow expansion of compartment if compressed
do not raise compartment above heart level as this will reduce the filling pressure and therefore are more prone to getting compartment syndrome
call for senior help as this is a true orthopaedic emergency
should you raise the limb of someone with suspected compartment syngrome?
do not raise compartment above heart level as this will reduce the filling pressure and therefore are more prone to getting compartment syndrome
what are the principles of decompression?
- long incisions (incise the whole of the compartment through all restrictions - skin and fascia)
- inspect all muscles (are they viable, do they contract)
- debride (excise all dead tissue)
- leave open (to relieve compression)
- 2nd look in 48hrs to check for further muscle death
what does this show?
decompression of the tibia
- 1st pic shows assessment of compartment
what does this show?
decompression of the forearm
what are the consequences of missed compartment syndrome?
- muscle ischaemia and necrosis
- muscle contractions
- delayed fracture healing (if fracture)
- may necessitate limbe amputation
what should you do in summary for suspected compartment syndrome?
if you suspect it, measure the compartment and if possible decompress the area (bandages)
call for senior help as soon as possible
this is a true orthopaedic emergency and delay in diagnosis and treatment means poor outcome
