TRAUMA Flashcards
Any patients presenting to A&E should be examined within 15 minutes of arrival to determine if they have suffered a serious brain or spine injury. Which patients should have a CT non-contrast within 1 hour of presentation?
GCS <13 on presentation
GCS <15 2hrs post injury
Post-traumatic seizure
1 episode of vomiting
Focal neurology
Open / depressed skull #
Evidence of basal skull #
Who should get a CT head within 8 hours post head injury?
Adult + LOC / amnesia + 1 of:
>65
Hx of bleeding / clotting disorders inc anticoagulation
>30 mins retrograde amnesia of events prior to injury
Dangerous mechanism of injury e.g. MVC
Initial assessment of a head injury should involve a comprehensive A-E. Discuss important head injury-related points in each stage.
A = assess if cervical spine injury likely. Jaw thrust should probably be used.
B = adequate oxygenation is even more important than usual, as secondary insult to brain because of hypoxia can worsen prognosis.
C = permissive hypotension is NOT indicated in head injury. Adequate tissue perfusion to brain is needed, normal CPP is 70mmHg in adults
D = GCS, should be repeated every 30-60 mins and when acute change is seen.
Also pupillary responses and focal neurological deficits should be checked.
Hypoglycaemia should be avoided.
E = facial #, depressed / basal fractures check for
A dilated pupil is a neurosurgical emergency. Why?
Can indicate raised ICP esp in context of a head injury.
Fixed dilated pupil can be secondary to herniation of brain through tentorium cerebelli causing compression of the parasympathetic fibres of CNIII; down and out eye, ptosis and constrictor pupillae affected.
Causes of a CN III palsy:
Uncal herniation
Vasculitis e.g. GPA
DM
PCA aneurysm
Weber syndrome (midbrain, with ipsilateral CNIII palsy and contralateral weakness)
MS
3 types of TBI:
Extradural haematoma
Subdural haematoma
SAH / intracerebral bleed
Primary brain injury can be focal or diffuse. Give types of injury in these two categories:
Focal: extra/subdural haematoma, intracerebral. Contusion e.g. coup or contre-coup
Diffuse: diffuse axonal injury causes shearing forces e.g. decel and acceleration forces, between border of grey and white matter due to different densities.
4 causes of secondary brain injury:
Infection
Cerebral oedema
Ischaemia
Tonsillar / tentorial herniation
Cerebral autoregulation is disrupted after an injury so brain is more susceptible to all these things.
Key red flag features in head injury (8):
Impaired consciousness
Dilated and fixed pupils
Basal skull #
Focal neurological deficit / visual disturbance
Seizure
Amnesia
Significant headache
N&V
Pupillary responses can give clues to the nature of the head injury. If the pupils are bilaterally constricted, give 3 potential causes:
Bilaterally constricted pupils:
Opioids
Pontine lesion
Metabolic
Pupillary responses can give clues to the nature of the head injury. If there is unilateral dilation of the pupil with sluggish light response or fixed, what is the likely interpretation? What would it likely be if bilateral?
CNIII palsy
Secondary to tentorial herniation, without the CNIII palsy
Encephalopathy
Bilateral:
Bilateral CNIII palsy
or
Poor CNS perfusion
Where is the bleeding in an extradural haematoma? Most common mechanisms of injury? Presenting features?
Between outer layer of dura and skull.
Acceleration / deceleration injury or blow to skull
Raised ICP and may have a lucid interval, then deterioration
Which artery is most likely affected in an extradural haematoma caused by a blow to which region of the skull?
Middle meningeal artery
Temporal
Subdural haematomas bleed into the outermost meningeal layer, with slower onset of symptoms and fluctuating consciousness. Which lobes are the most likely affected, and give some risk factors.
Frontal and parietal lobes
Older age
Anticoagulation
Alcohol
Patients with an intracerebral haemorrhage can present similarly to an ischaemia stroke or with a decrease in consciousness. What are some causes / risk factors for an intracerebral haemorrhage?
HTN
Vascular lesion e.g. aneurysm (most common cause of SAH)
Trauma
Brain tumour
Infarct esp patients undergoing thrombolysis
Minimal cerebral perfusion pressure in adults and children:
70mmHg adults
40-70mmHg children
CPP = MAP-ICP
Definition of a flail chest:
At least 2 ribs broken in at least 2 places
Chest wall detaches from thoracic cage, giving abnormal chest wall motion
Most common cause of tension pneumothorax?
Mechanical ventilation in patients with pleural injury
Laceration of which artery is most likely to cause a haemothorax, and when is surgical exploration indicated?
Internal mammary
Surgical exploration indicated if:
>1500ml drained immediately
or
>200ml / hr for at least 2 hours
36F chest drain should be used
What is pulsus paradoxus and when does it occur?
Drop is systolic BP of >10mmHg during inspiration
Best diagnostic test for a rib fracture? Key intervention in simple rib fractures?
CT Chest for # and soft tissue injury
Analgesia important, to allow adequate breathing and chest expansion
If strong oral / IV not helping, ?intercostal nerve block
Types of injury that can result from chest trauma:
Pneumothorax
Haemothorax
Flail chest
Cardiac tamponade
Pulmonary contusion - significant hypoxia, acidosis, high mortality
Trauma triad of death:
Acidosis
Hypothermia
Coagulopathy
Which organ is most commonly damaged in stab wounds to the abdomen?
Liver
What does blood at the urethral meatus suggest?
Urethral tear
What does a high riding prostate on PR exam suggest?
Urethral disruption
A patient has a mediastinal traversing stab wound. Which 2 investigations are indicated in this specific trauma?
CT angiogram (is there is a mediastinal haematoma there is high chance of a great vessel injury)
Oesophageal contrast swallow
Which type of chest wall trauma is common, lethal and requires early intubation and ventilation?
Pulmonary contusion
Most commonly used classification system for pelvic ring injuries, and describe how it is calculated?
Young-Burgess
Uses vector of the disrupting force (i.e. direction) and the degree of resulting displacement.
Anterior-posterior
Lateral
Vertical sheer
5 aetiological groups of shock:
Cardiogenic
Neurogenic
Septic
Anaphylactic
Haemorrhagic
Urine output in haemorrhagic shock I, II, III and IV:
> 30
20-30
50-15
<5
Blood loss in ml and % for class I-IV of haemorrhagic shock:
I = <750ml / <15%
II = 750-1500ml / 15-30%
III = 1500 - 2000ml / 30-40%
IV = >2000ml / >40%
In patients suffering from trauma, the most likely cause of shock is haemorrhage, but can also be caused by / contributed to by:
Tension pneumothorax (cardiogenic)
Spinal cord injury (neurogenic)
Myocardial contusion (cardiogenic)
Cardiac tamponade (cardiogenic)
To generate a palpable femoral pulse an arterial pressure of ? is required:
> 65 mmHg
What is the most common cause of neurogenic shock, and describe the pathophysiology, and management option.
Spinal cord transection
Disrupts the autonomic nervous system, either causing decreased sympathetic action or increased parasympathetic action.
These both cause decreased peripheral vascular resistance, resulting in marked vasodilation.
This vasodilation decreases preload, therefore cardiac output, tissue perfusion = SHOCK
Peripheral vasodilators CAN be used in neurogenic shock to return vascular tone to normal e.g. metaraminol
Causes of cardiogenic shock:
Ischaemic heart disease
Trauma to heart inc. contusion / MI / tamponade etc
Best site for adrenaline injection in anaphylaxis and DOSE + definition of anaphylaxis:
Anterolateral aspect of middle 1/3 of thigh
500 micrograms of 1:1000 adrenaline.
Repeat after 5 mins if no improvement
Unilateral constricted pupil in head injury, which pathway affected?
Sympathetic
Cushing’s triad (late stage) in head injury:
Hypertension
Bradycardia (baroreceptors on aortic arch detecting hypertension)
Irregular respirations (brainstem involvement)
Discuss why hypertension is present in raised ICP, including CPP equation.
CPP = MAP - ICP
In raised ICP the CPP drops, as the systolic BP cannot overcome the increase resistance in the brain.
The only way to maintain CPP, according to equation, is to increase the MAP, which occurs due to sympathetic activation.
Causes of raised ICP:
IIH
Traumatic head injury
Infection e.g. meningitis
Tumours
Hydrocephalus
