Moderate and severe traumatic brain injury: Viva

Branching clinical structured oral on moderate and severe paediatric traumatic brain injury covering the Glasgow Coma Scale severity bands and the paediatric verbal modification, the pathophysiology of raised intracranial pressure and the cerebral perfusion pressure equation, the stepwise intracranial pressure management ladder with the guideline thresholds and hyperosmolar doses, the prevention of secondary brain injury, and the appraisal of the Hutchison hypothermia and DECRA decompressive craniectomy trials.

branching clinical structured oral3 min readVerification in progress

Prompt

An 8-year-old girl is brought to the emergency department after a high-speed motor vehicle crash. She opens her eyes to pain, makes incomprehensible sounds, and abnormal flexes to pain, giving a Glasgow Coma Scale of 6. Her systolic blood pressure is 70 mmHg, her oxygen saturation is 90 percent, and a computed tomography shows diffuse swelling with a small left frontal contusion but no surgical mass. The examiner asks how you grade the severity, why the hypotension matters, how you run the intracranial pressure ladder, and how you appraise the trial evidence.

Branch 1: Severity grading and the meaning of the hypotension

The candidate should grade the injury as severe using the Glasgow Coma Scale. A strong candidate states that the scale scores eye opening from 1 to 4, verbal response from 1 to 5, and motor response from 1 to 6, that the total of 6 places the child in the severe band of 3 to 8, and that the line that matters is at 8, because a child at or below 8 cannot protect the airway and is at high risk of raised intracranial pressure. The candidate should add that the verbal component is modified for the preverbal child, with the score of 5 for coos and babbles down to 1 for no response, as reviewed by Kirkham. [1][2]

If the examiner presses on the hypotension, the candidate should explain that a single hypotensive episode doubles the mortality in severe paediatric traumatic brain injury, because the falling mean arterial pressure collapses the cerebral perfusion pressure. The candidate should link this to the equation that cerebral perfusion pressure equals mean arterial pressure minus intracranial pressure, and state that the blood pressure is therefore defended from the first contact with isotonic fluid and blood. [4]

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References6Show ledger

[1]Teasdale G, Jennett B Assessment of coma and impaired consciousness. A practical scale. Lancet, 1974.PMID 4136544
[2]Kirkham FJ, Newton CR, Whitehouse W Paediatric coma scales. Dev Med Child Neurol, 2008.PMID 18312424
[4]Kochanek PM, Carney N, Adelson PD, et al Guidelines for the acute medical management of severe traumatic brain injury in infants, children, and adolescents--second edition. Pediatr Crit Care Med, 2012.PMID 22217782
[5]Kochanek PM, Tasker RC, Carney N, et al Guidelines for the Management of Pediatric Severe Traumatic Brain Injury, Third Edition: Update of the Brain Trauma Foundation Guidelines, Executive Summary. Neurosurgery, 2019.PMID 30822776
[7]Hutchison JS, Ward RE, Lacroix J, et al Hypothermia therapy after traumatic brain injury in children. N Engl J Med, 2008.PMID 18525042
[8]Cooper DJ, Rosenfeld JV, Murray L, et al Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med, 2011.PMID 21434843