Download Crush Injury - WordPress.com

Crush Injury
Rhabdomyolysis
Aetiology
Mechanical: trauma; electrocution, severe burns; prolonged immobilisation; external
compression (eg. POP, splint); severe exertion; haemorrhage; oedema
Drugs: toluene, amphetamines, heroin, theophylline, simvastatin, arsenic, alcohol
withdrawal
Toxins: snake / spider
Other: sepsis, post-ischaemic limb (including tourniquet >1hr), neuroleptic malignant
syndrome, malignant hypertension, heatstroke, frost bite, serotonin syndrome,
prolonged seizures, inflammatory myopathy, thyroid storm, K <2.5
Assessment
Symptoms: tender swollen muscles
Bloods: CK >10,000-100,000 usually (always >1000; CK >75,000 predictive of acute
renal failure and death)
 K / phosphate / urea
 calcium (most common metabolic abnormality) / albumin / pH
Urine: myoglobinuria (red/brown urine, Hb on dip; risk of acute renal failure if urine
myoglobin >20,000mcg/L)
ECG: arrhythmia is cause of early death (otherwise death at 3-5/7 from acute renal
failure, DIC, sepsis)
Management
Avoid suxamethonium; treat hyperkalaemia; watch for worsening hypocalcaemia as
you treat; cool if needed, control seizures, treat cause
Oliguric: aim UO >2ml/kg/hr; needs 0.9% saline @ 1L/hr for 1st 4hrs
Place IDC; mannitol (causes renal vasodilation,  renal tubular blood flow, osmotic
diuresis); CVP monitor if UO inadequate despite this  commence dopamine if
CVP normal but UO low
Urinary alkalinisation: 50mmol NaHCO3 in 1st hr; aim urinary pH >7; will 
myoglobin’s renal toxicity
Anuric / fluid overloaded: haemodialysis
Aetiology
As above plus injection / infusion; fracture is most common cause (tibial,
supracondylar humerus, femoral); especially if very muscly, young male, on
steroids, coagulopathy
High risk compartment if skin on one side and bone/intraosseous membrane on other
(eg. Anterior / peroneal / posterior compartment lower leg, extensor / flexor
compartment forearm, intrinsic muscle compartments of hand)
Pathology
 hydrostatic tissue pressure in compartment  compression of veins, muscles,
nerves, arteries  irreversible ischaemic injury if >8hrs  Volkmann’s contracture
Onset 6-24hrs after injury
Early: pain out of proportion, throbbing, on passive movement; pain even after
reduction; severe tenderness over anterior muscle compartment rather than
fracture line); venous congestion (strong pulses do not exclude)
Late: paraesthesia / numbness; may not got paraesthesia in hand and motor deficits
may be subtle; loss of vibration sense (earliest)  sensation  motor loss very
late;  distal pulses / CRT; induration
Compartment
Syndrome
Symptoms
Tibial fracture: 40% due to tibial fracture (incidence up to 20%; can occur with open
fracture)
Anterior comptmt: enclosed by tibia, IO membrane, anterior crural septum; weakness
of toe extension / foot dorsiflexion; pain on passive toe flexion;  sensation 1st web
space (deep peroneal nerve); anterior tibial artery
Lateral comptmt: enclosed by anterior crural spetum, fibula, posterior crural septum;
Weak foot plantar flexion and eversion;  sensation dorsum of foot (superior
peroneal nerve)
Symptoms
(cntd)
Acromioclavicular Joint
Dislocation
Investigation
Management
Deep posterior comptmt: more common that superficial; Weakness toe plantar flexion,
foot inversion;  sensation to sole of foot (posterior tibial nerve); Posterior tibial
artery
Superior posterior comptmt: weakness knee and ankle flexion;  sensation lateral
aspect foot and calf (sural nerve)
Measure compartment pressure if evidence of  pressure but not warranting
fasciotomy (also if distracting injury, ETOH, intubated)
Normal = 0-10mmHg
Compromise = 20-30
Absent capillary blood flow = >35
Delta pressure = DBP – ICP = better determinant than ICP alone = danger if <30
Analgesia; elevation; remove compressive force
Indications for immediate fasciotomy: evidence of vascular compression
Indications for ASAP fasciotomy: significant neuro symptoms; ICP >35; delta pressure
<30; rhabdomyolysis