Trauma/Burns

Question 1

Compartment syndrome

Answer 1

> 30mmHg or >30mmHg difference between compartment and diastolic BP

Pain out of proportion to injury
Paraesthesia, paralysis, skin changes, venous congestion

Needle with pressure transducer inserted into compartment - zeroed at level of compartment being measured

Mx - mx BP, cut off cast, limb at level of heart, ortho, fasciotomies, mx AKI/rhabdo if occur

Question 2

Burns

Answer 2

Extent on burns
1 - rule of 9s (head, arm, leg anterior, leg posterior, torso 18%, back 18%, perineum 1%)
2 - Lund-browder charts
3 - hand = 1%

Fluids
Parkland formula = 4mls/kg x TBSA burn - 50% in 8 hrs and 50% in 16 hrs

Question 3

Rhabdomyolysis

Answer 3

Causes:
1 - Trauma - burns, crush
2 - Drugs - statins, cocaine, amphetamines
3 - MH, Serotonin syndrome, NMS
4 - Thyroid storm, phaeo 

Pathophysiology: damage to calcium-ATPase pump in myocytes, increase in sarcoplasmic calcium with unopposed contraction, skeletal muscle disintegration, release of intracellular proteins and electrolytes

High phosphate, urate, K, myoglobin.
Low calcium

Complications:
1 - AKI - myoglobin casts causing tubular obstruction, myoglobin also causes renal vasoconstriction
2 - Electrolyte emergencies
3 - DIC

Mx:
Fluids
Correct electrolytes
Bicarbonate - aim urine pH >6.5 to reduce myoglobin precipitation 
RRT

Question 4

Drowning

Answer 4

Resp compromise due to submersion (airway below liquid) or immersion (liquid across face)

Fresh water and salt water drowning

RFs: Young children and adults, intoxication, pre-existing neuro disease (epilepsy), occupation and hobbies, previous self harm

Diving reflex - apnoea, bradycardia and vasoconstriction - aims to conserve O2

Pathophys:
1 - CVS - catecholamine surge and myocardial dysfunction/arrythmias, pulm oedema
2 - Resp - breath holding, laryngospasm, hypoxia, hypercapnia, alveolar toxicity, surfactant washout and bronchospasm, pulm oedema and pulm HTN —- ARDS
3 - Neuro - hypoxia brain injury
4 - Metabolic - hypothermia
5 - Infective - gram +ve from upper airway, gram -ve in fresh water

Mx:
ABCDE +/- c-spine control
Optimise O2, I&V, lung protective vent, bronch
Inotropes, fluids
Warm to 35
Correct electrolytes
Manage associated issues - eg intoxication, c-spine, TBI

Survival factors:
1 - Age - young better
2 - Type of drowning
3 - Vol of aspiration - >22ml/kg 
4 - length of submersion - > 10mins
5 - Low GCS or unreactive pupils on presentation
6 - Cardiac arrest
7 - pH < 7.1 on presentation