Head trauma Flashcards
Primary goal for treated suspected traumatic brain injury
Prevent secondary brain injury
Cushing response to raised ICP
High BP
Bradycardia
Irregular resps
Monro-Kellie doctrine
- the total volume of the intracranial contents must remain constant -
as mass affects the intracranial closed space, there must be a change in some aspect of the intracranial contents
- new mass introduced eg tumour or haemorrhage, there will be a shift. CSF and blood equilibrate first, then brain, leading to impending herniation
Uncal herniation
Ipsilateral pupillary dilation with contralateral hermiparesis
Uncus and its significance in herniation
Medial part of temporal lobe
- herniates through tentorial nortch
- compression of midbrain and contralateral hemiparesis
Normal ICP
10 mm Hg
Cerebral perfusion pressure (CPP) =
Mean arterial pressure - intracranial pressure
Traumatic brain injury effect of BP on brain
MAP too low - ischaemia and infarction
MAP too high - brain swelling
CPP = MAP - ICP
Physical exam findings suggesting cranial or intracranial injury
Facial fractures of midface with instability of maxilla/orbital complex
Auditory canal haemorrhage - temporal bone fracture
Retroauricular ecchymosis (battle’s sign) - basal skull fracture
Asymmetric, non reactive pupil - lateralising intracranial haemorrhage, or 3rd nerve injury
Clinical signs of basilar fracture
Raccoon eyes
Battle’s sign
Rhinorrhea
Otorrhea
Facial paralysis
Hearing loss
Diffuse intracranial lesions (3 examples)
Concussion
Severe injury
Diffuse axonal injury
Concusion
Transient, nonfocal neuro disturbance
Often loss of consciousness
Severe diffuse intracranial injury results from
Results from hypoxic, ischaemic insult to brain from prolonged shock or apnoea
Diffuse axonal injury
Shearing injury
Seen in high velocity impact or deceleration injuries
Often poor outcome
Epidural haematoma
Uncommon
Often temporal or temporoparietal regions
Often middle meningeal
Classic presentation: lucid interval
Appear lenticular or biconvex on CT
Subdural haematoma
More common than epidural
Typically from shearing of blood vessels of cerebral cortex
Damage is severe due to underlying brain injury
CT: appear to cover cerebral surface
Cerebral contusion
Fairly common
Mostly frontal and temporal lobes
Can evolve to form intracerebral haematomas or coalescent contusions
Repeat CT scan these in case of progressive change
CT head findings that would indicate injury severe enough to warrant intervention
- midline shift
- loss of definition of basal cisterns
- severe skull fractures with intrusion into brain matter
Elderly patient characteristics to consider in (head) trauma
Antiplatelets
Beta blocker
Anticoag
comorbidities: CAD, stent, rate control for arrhythmias
Signs for suspected mild brain injury
Witnessed LOC
Definite amnesia
Witnessed disorientation in a patient with GCS 13-15
Head CT if suspected mild brain trauma and one of the following:
High risk for neurosurgical intervention
Moderate risk for brain injury on CT
High risk for neurosurgical intervention
GCS <15 at 2 hours post injury
Suspected open or depressed skull fracture
Basilar skull fracture sign
Vomiting more than twice
>65 yo
Anticoagulation
Moderate risk for brain injury on CT
LOC <5 mins
Amnesia before impact >30 mins
Dangerous mechanism (eg height more than 3 feet)
Mild brain injury management
If abnormal CT or persistent sx, admit and consult neurosurgery
If asymptomatic, awake/alert: observe for several hours, re examine and safely discharge
Management of moderate brain injury (GCS 9-12)
Brief hx and stabilise pt
Then neuro assessment
CT head –> again in 24 hrs
Contact neurosurgeon
Admit for observation
Management of severe brain injury (GCS 3-8)
ABCDE
Secondary survey
Admit to neurosurgery centre
Therapeutic agents
- mannitol
- hypertonic saline
Priorities for initial evaluation and triage of patients with severe brain injury (5)
- ABCDE
- Neuro exam once BP normalised
- Target hypotension - if SBP <100, work out why eg FAST
- If SBP >100 after resus and there is intracranial mass, CT head now takes priority over trauma scans
- In borderline cases, try to get CT head before laparotomy if possible
The above is true for >110 for patients 15 to 49, or 70+
In brain injury, aim partial pressure of CO2 at approximately
35 mmHg
True or false: intracranial haemorrhage cannot cause haemorrhagic shock
True
Seizures in traumatic brain injuries should be treated with
Benzodiazepines
Repeat CT head should be done with 24 hours of head injury in:
- patients with subfrontal/temporal intraparenchymal contusions
- those on anticoagulation
- pts older than 65
- intracranial haemorrhage with a volume of >10ml
Clinical signs of basilar skull fracture
Raccoon eyes
Battle’s sign
Rhinorrhea
Otorrhea
Facial paralysis
Hearing loss
Heparin and LMWH reversal
Protamine sulfate
Contraindication to mannitol
Systemic hypotension
Agent for elevated intracranial pressure, esp when hypotensive
Hypertonic saline
Control acute seizures post traumatic brain injury with
Phenytoin
Diagnostic criteria for brain death (5)
GCS 3
Non reactive pupils
Absent brainstem reflexes
No spontaneous ventilatory effort
Absence of confounding factors such as alcohol, drug intoxication or hypothermia
