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TBI & Glasgow Coma Scale. Mandy Freeman March 2010. Aims. Highlight types of traumatic brain injuries (TBI) Highlight the importance of Glasgow Coma Scale. Aetiology. Annual incidence (US) – 180-220 cases per 100,000 i.e. 600,000 new cases per year (Tennant 1995) Fatal 10%
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TBI & Glasgow Coma Scale Mandy Freeman March 2010
Aims • Highlight types of traumatic brain injuries (TBI) • Highlight the importance of Glasgow Coma Scale
Aetiology • Annual incidence (US) – 180-220 cases per 100,000 i.e. 600,000 new cases per year (Tennant 1995) • Fatal 10% • GCS - Mild – 75-80 %, moderate – 10%, severe – 10% • Permanent disability • 100% in severe, 66% in moderate • Male to female ratio – 2:1 (Sosin et al 1996) • Age Range ?
Most common causes?? • (Royal College of Surgeons of England 2007)
Pathophysiology • Skull – rigid, inelastic container • = Vol (Brain) + Vol (CSF) + Vol (Blood) = 80% + 10% + 10% • Monro-Kellie Doctrine – states that total intracranial volume is fixed because of the inelastic nature of the skull • Intracranial compliance – change in the pressure due to the change in volume • Cushings Triad -Sign of ICP
ºLaceration ºBOS # ºContusion ºAbrasion SKULL ºLaceration ºConcussion ºContusions ºEDH – ºSubdural: ºCranial # ºICH ºSAH
EDH • Extradural hematomas • Between inner table of skull and dura • Biconvex • Arterial injury – enlarge rapidly • Venous in around 10% • Classic example – temporal EDH by fracture through course of middle meningeal artery • Lucid interval before deteriorating • If tackled early – good prognosis for isolated lesion
SDH • Subdural hematoma • Between dura and brain • Outer edge – convex, inner – concave • Not limited by suture lines • Usually venous – bridging veins (cortex to dura) • In elderly brain more common due to cerebral atrophy
Management • Mild Head Injury • 3% will progress to more serious injuries • Concussion – majority have concussion – physiological injury to brain without structural alteration • Monitored • Would require neurological observations • When discharged instructed to seek medical attention if severe headache, persistent nausea and vomiting, seizure, confusion, unusual behaviour, watery discharge from ear or nose
Contusions • Most common and evident in minor and major head injuries • Can present with GCS 15/15 worsening over day 3 to 5 Strict fluid balance 2 litre restriction 4hrly Observations
Diffuse Axonal Injury • Neuronal injury in subcortical gray matter or brain stem due to rotation or deceleration injury • Patients with severely depressed level of consciousness • CT – no significant injury • ICP – within reference range • Prognosis - poor
GCS Severity of Head Injury • Mild head injury – GCS 15 - 13 • Moderate head injury – GCS 12 – 9 • Severe head injury – GCS 8 and below
Developed by Jennett and Teasdale (1974) • Assess level of consciousness • 3 categories • Eye opening – E • Motor response – M • Verbal response – V
Glasgow Coma Scale • Best Verbal response • 5 – oriented and converses • 4 – disoriented and converses • 3 – inappropriate words • 2 – incomprehensible sounds • 1 – No response Eye opening 4 – spontaneously 3 – to verbal commands 2 – to pain 1 – No response • Best Motor response • 6 – obeys commands • 5 – Localizes to pain • 4 – flexion withdrawal • 3 – abnormal flexion • 2 – extension • 1 – no response Best – 15 Worst - 3
Poor Outcome • Age older than 60 years • GCS of <5 • Presence of fixed pupil • Prolonged hypotension or hypoxia • Presence of surgical treatable mass lesion
NAI Children • Child with head injury – NAI must be excluded • HI is most common cause of morbidity and mortality in NAI • Multiple bilateral skull fractures, subdural hematomas of different ages, cortical contusions and shear injuries, cerebral ischaemia, retinal haemorrhages
Dunn L, Henry J, Beard D. Social deprivation and adult head injury: a national study. (2003) J Neurol Neurosurg Psychiatry. 74:1060–1064 • National Institute for Clinical Excellence. (2007) Triage, assessment Investigation and early management of head injury in infants, children and adults Clinical Guidelines CG56. NICE; • Swann IJ, Walker A. (2001) Who cares for the patient with head injury now? Emerg Med.18:352–357. • Sosin DM, Sniezek JE, Thurman DJ. (1991) Incidence of mild and moderate brain injury in the United States. Brain Injury. 1996;10:47–54. • Thornhill S, Teasdale G, Murray GD, McEwen J, Yoy CW, Penny KI. Disability in young people and adults one year after head injury: prospective cohort study. BMJ.2000;320:1631–5
Tennant A. Epidemiology of head injury. (1995) In: Chamberlain MA, Neumann VC, Tennant A, editor. Traumatic Brain Injury Rehabilitation: Services, treatments and outcomes. London: Chapman & Hall