Acute Compartment Syndrome

Question 1

what are the clinical effects of an ischaemic problem (let’s say in the forearm after a fracture)?

Answer 1

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

Question 2

what is anterior tibial syndrome?

Answer 2

acute inflammatory condition after leg injury. This included: - swelling - pain - erythema this was due to high tissue pressures causing ischaemia

Question 3

what are the main things to remember about acute compartment syndrome?

Answer 3

limb threatening should always have a high index of suspicion for ACS Key pathology = ISCHAEMIA

Question 4

what is the aetiology of acute compartment sysndrome? name at least 4

Answer 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

Question 5

how does compartment syndrome develop?

Answer 5

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

Question 6

what are the at risk sites for compartment syndrome? high to low risk order

Answer 6

LOWER LEG forearm hand foot thigh

Question 7

where can compartment syndrome occur?

Answer 7

in any muscle compartment bounded by inelastic walls - sheets of fascia and bone

Question 8

why does compartment syndrome occur in muscle with inelastic walls?

Answer 8

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.

Question 9

what types of vessels are compressed first to last in acute compartment syndrome?

Answer 9

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

Question 10

what does it mean if the foot is pink warm and has a pulse however you suspect that the leg has Acute compartment syndrome?

Answer 10

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

Question 11

what is the progression in tissue damage in acute compartment syndrome? why is this good?

Answer 11

• 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

Question 12

what is needed for the regeneration of muscle and nerves?

Answer 12

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

Question 13

what is tissue damage proportional to? give examples

Answer 13

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

Question 14

who is most likely to develop acute compartment sysndrome form trauma?

Answer 14

Question 15

who is most likely to develop acute compartment sysndrome form no trauma?

Answer 15

Question 16

in trauma patients for acute compartment syndrome, what is teh epidemiology for those with fractures vs those without fractures?

Answer 16

Question 17

what fractures are more common in young adults vs children?

Answer 17

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

Question 18

what are the main causes of compartment syndrome in patients with no tracuma?

Answer 18

usually due to prolonged immobility

also seen in patients who have been on long term anti-coagulants

Question 19

Is Acute compartment syndrome more frequent in hig or low energy injuries?

Answer 19

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

Question 20

can acute compartment occur in open fractures?

Answer 20

yes because compartments will often remain intact in open fractures.

Question 21

how do we diagnose acute compartment syndrome?

Answer 21

mostly clinical and dependant on symptoms and signs seen

Question 22

what are the classical findings in acute compartment syndrome?

Answer 22

The 5 P:

• Pain (particularly on passive movent)
• Paraesthesiae - site depends on compartment
• Paresis or paralysis
• Pallor - variable
• Pulselessness - very late

Question 23

if there is damage wo your shin and you get parasthesiae, where are you most likely goint to feel it?

Answer 23

in the first webspace of foot

Question 24

out of the 5 Ps in clinical diagnosis of acute compartment syndrome, what are the main Ps we are interested in?

Answer 24

Question 25

how can we clinically and objectively measure acute compartment syndrome?

Answer 25

we can check the pressure of the compartment through stryker slit cathater

we are interested in delta pressure

Question 26

what should compartment pressure be normally? what happens if its out of range?

how is it calculated?

Answer 26

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

Question 27

why are people suspected with/have compartement sundrome constantly monitered?

Answer 27

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

Question 28

apart from patients with suspected acute compartment syndrome, what pressures should we also measure in other patients?

Answer 28

polytrauma

head injury

children

high energy fractures

crush

burns

arterial injuries post repair

overdose

Question 29

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?

Answer 29

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

Question 30

should you raise the limb of someone with suspected compartment syngrome?

Answer 30

do not raise compartment above heart level as this will reduce the filling pressure and therefore are more prone to getting compartment syndrome

Question 31

what are the principles of decompression?

Answer 31

• 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

Question 32

what does this show?

Answer 32

decompression of the tibia

• 1st pic shows assessment of compartment

Question 33

what does this show?

Answer 33

decompression of the forearm

Question 34

what are the consequences of missed compartment syndrome?

Answer 34

• muscle ischaemia and necrosis
• muscle contractions
• delayed fracture healing (if fracture)
• may necessitate limbe amputation

Question 35

what should you do in summary for suspected compartment syndrome?

Answer 35

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