Head and Facial Injury - PowerPoint PPT Presentation

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Head and Facial Injury
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Head and Facial Injury

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  1. Head and Facial Injury Scott Marquis, MD

  2. Overview • Head injury • What to look for • Appropriate management • Facial injury • Review

  3. Head and brain trauma • ~ 1,500,000 head injuries annually • ~ 230,000 hospitalized and survive • ~ 50,000 deaths • 1/3 all injury-related deaths • Severity • 75% mild • 10% moderate • 10% severe (35% mortality, 5% c-spine fx) • 80,000-90,000 significant long-term disability

  4. Head & brain trauma • Risk Groups • Highest: Males 15-24 yrs of age • Very young children: 6 mos to 2 yrs of age • Young school age children • Elderly >75 yrs

  5. Head injury • Broad and Inclusive Term • Traumatic insult to the head that may result in injury to soft tissue, bony structures, and/or brain injury • Blunt Trauma • Penetrating Trauma

  6. Brain injury • “A traumatic insult to the brain capable of producing physical, intellectual, emotional, social and vocational changes” • Three broad categories • Focal injury • Cerebral contusion • Intracranial hemorrhage • Epidural hemorrhage • Subarachnoid hemorrhage • Diffuse Axonal Injury • Concussion

  7. Mechanisms of head injury • Motor vehicle crashes, MVC • Most common cause of head trauma • Most common cause of subdural hematoma • Sports injuries • Falls • Common in elderly and in presence of alcohol • Associated with subdural hematomas • Penetrating trauma • Missiles more common than sharp projectiles

  8. Categories of injury • Coup injury • Directly posterior to point of impact • More common when front of head struck • Contrecoup injury • Directly opposite the point of impact • More common when back of head struck

  9. Categories of injury • Diffuse axonal injury (DAI) • Shearing, tearing or stretching of nerve fibers • More common with vehicle occupant and pedestrian • Focal injury • Limited and identifiable site of injury

  10. Causes of brain injury • Direct (primary) causes • Impact • Mechanical disruption of cells • Vascular permeability or disruption • Indirect (secondary or tertiary) causes • Secondary • Edema, hemorrhage, infection, inadequate perfusion, tissue hypoxia, pressure • Tertiary • Apnea, hypotension, pulmonary resistance, ECG changes

  11. The brain is enclosed in a box

  12. Brain anatomy • Occupies 80% of intracranial space • Divisions • Cerebrum • Cerebellum • Brain Stem

  13. Brain anatomy • Cerebral spinal fluid, CSF • Clear, colorless • Circulates throughout brain and spinal cord • Cushions and protects • Ventricles • Center of brain • Secrete CSF by filtering blood • Forms blood-brain barrier

  14. Brain anatomy • Blood Supply • Vertebral arteries • Supply posterior brain (cerebellum and brain stem) • Carotid arteries • Most of cerebrum

  15. Brain anatomy • Meninges • Dura mater: tough outer layer, separates cerebellum from cerebral structures, landmark for lesions • Arachnoid: web-like, venous vessels that reabsorb CSF • Pia mater: directly attached to brain tissue

  16. Scalp lacerations • Scalp laceration or avulsion • Most common injury • Vascularity = diffuse bleeding • Generally does not cause hypovolemia in adults • Can produce hypovolemia in children

  17. Scalp anatomy • Scalp • S: skin • C: connective tissue • A: aponeurosis (galea) • L: loose areolar tissue • P: pericranium • Scalp very vascular • major blood loss • watch kids and adults with prolonged extrication

  18. Skull fracture

  19. Skull fracture • Present in 60% of pts with severe head injury • Types: • Linear: usually incidental finding on CT • Depressed: mechanism is usually intense blow to scalp with object of small surface area. Surgical repair needed if depressed more than 5mm

  20. Skull fracture • Types • Basilar: blow to temporal (most often), parietal, occipital area • Signs • Hemotympanum or bloody ear discharge • Rhinorrhea or otorrhea • Battle’s sign • Racoon’s eyes • Cranial nerve palsies

  21. Closed head injuries • Focal • Contusion • Epidural hematoma • Subdural hematoma • Intracerebral • Diffuse (most common type of head injury) • Mild concussion • Classic concussion • Diffuse Axonal Injury (DAI)

  22. Blood between skull and dura Usually arterial tear Middle meningeal artery Causes increased ICP Epidural hematoma

  23. Epidural hematoma • Unconsciousness followed by lucid interval • Rapid deterioration • Decreased LOC, headache, nausea, vomiting • Hemiparesis, hemiplegia • Unequal pupils (dilated on side of clot) • Increase BP, decreased pulse (Cushing’s reflex)

  24. Between dura mater and arachnoid More common Usually venous Bridging veins between cortex and dura Causes increased intracranial pressure Subdural Hematoma

  25. Subdural hematoma • Slower onset • Increased ICP • Headache, decreased LOC, unequal pupils • Increased BP, decreased pulse • Hemiparesis, hemiplegia

  26. Intracerebral hematoma • Usually due to laceration of brain • Bleeding into cerebral substance • Associated with other injuries • DAI • Neuro deficits depend on region involved and size • Repetitive with frontal lobe • Increased ICP

  27. Concussion • Transient loss of consciousness • Retrograde amnesia, confusion • Resolves spontaneously without deficit • Usually due to blunt head trauma

  28. Diffuse axonal injury • Tearing or shearing of nerve fibers at time of impact • Rapid acceleration-deceleration injury (MVA) • Functional or physiologic dysfunction • Not gross anatomic abnormality • Most common CT finding after severe head trauma

  29. Diffuse axonal injury • Prolonged post-traumatic coma not due to mass lesion or ischemic insults • Coma begins at time of trauma • Usually evidence of decorticate or decerebrate posturing, autonomic dysfunction (HTN, fever)

  30. Penetrating head injury • Severity depends on • Energy of missile • Path • Amount of scatter of bone and metal fragments • Presence of mass lesion • Accompanied by • Severe face and neck injuries • Significant blood loss • Difficult airway • Spinal instability

  31. What the brain needs • High metabolic rate • Consumes 20% of body’s oxygen • Largest user of glucose • Requires thiamine • Can not store nutrients

  32. More on brain workings • Perfusion • Cerebral blood flow (CBF) • Dependent upon CPP • Flow requires pressure gradient • Cerebral perfusion pressure (CPP) • Pressure moving the blood through the cranium • Autoregulation allows BP change to maintain CPP • CPP = mean arterial pressure (MAP) - intracranial pressure (ICP)

  33. More on brain workings • Perfusion • Mean Arterial Pressure (MAP) • Largely dependent on cerebral vascular resistance (CVR) since diastolic is main component • Blood volume and myocardial contractility • MAP = diastolic + 1/3 pulse pressure • Usually require MAP of at least 60 mm Hg to perfuse brain

  34. More on brain workings • Perfusion • Intracranial pressure (ICP) • Edema, hemorrhage • ICP usually 10-15 mm Hg • Cerebral perfusion pressure CPP = MAP - ICP

  35. What goes wrong in head injury • As ICP  and approaches MAP, cerebral blood flow  • Results in  CPP • Compensatory mechanisms attempt to  MAP • As CPP , cerebral vasodilation occurs to  blood volume • This leads to further  ICP,  CPP and so on