1. CHAPTER 6 HEAD TRAUMA

2. OBJECTIVES u A.Understand basic intracranial anatomy & physiology u B.Evaluate a patient with a head injury u C.Perform the necessary stabilization procedures u D.Determine the appropriate disposition of the patient

3. Introduction u 10 % of head injury die prior to reaching a hospital u Head injury can be divided: – mild ( 80 % ) – moderate (10 % ) – severe (10 % ) u avoid secondary brain damage ( support vital signs, avoid & treat IICP ) u Obtaining a CT Scan should not delay patient transfer ( transfer patient early ) u Neurosurgical consult essential

4. Neurosurgen need know 1.Age of patient & the mechanism and time of injury 2.Vital signs ( particular the blood pressure ) 3.Results of minineurologic examination ( GCS score; particular the motor response, and pupillary reaction ) 4.Associated injury 5.Results of the diagnostic studies ( CT scan )

5. Anatomy & Physiology u SCALP – S: Skin – C: Connective tissue – A: Aponeurosis / galea aponeurotica – L: Loose areolar tissue – P: Pericranium – Pitfalls Bleeding from Scalp laceration will result in shock ( especialling in children )

6. Anatomy & Physiology u Brain – Cerebrum 1. Frontal: emotion, motor function & expression of speech ( motor speech areas ) 2. Parietal: sensory & spatialorientation 3. Temperal: memory function, responsible for speech 4. Occipital: vision – Brain Stem 1. Midbrain: reticular activating system 2. Pons: reticular activating system 3. Medulla: cardiorespiratory center 4. Cerebellum: coordiration & balance

7. Anatomy & Physiology u Tentorium – Supratentorial compartment ( anterior & middle cranial fossa ) » Uncal herniation ( Supratentorial pressure ): ipsilateral pupillary dilation & contralateral hemiplegia – Infratentorial compartment ( posterior fossa )

8. Anatomy & Physiology u Intracranial Pressure: Hemostasis Kicp V CSF + V Bl + V Br Pitfalls: A normal intracranial pressure dose not necessarily exclude a mass lesion ( compensation stage )

9. Pressure / Volume Curve ICP Herniation 10 point of decompensation volume of mass keep the patient’s pressure & volume in the flat portion of the curve, rather than to treat the patient at the point of decompensation Intracranial Pressure

10. Increased Intracranial Pressure ( IICP ) Result in – Decreased cerebral perfusion pressure ( CPP ) » CPP : Mean Arterial Blood Pressure- ICP – Altered level of consciousness

11. Anatomy & Physiology Autoregulation of Cerebral blood flow ( CBF ) u Noninjured person: CBF is consiant between mean blood pressure of 50 and 160 mm Hg u Head-injured patient: autoregulation is often disturbed, so he vulnerable to secondary brain injury due to ischemia from hypotensive episode ( keep vital signs is very important )

12. Classification of Head Injury u Mechanism of injury u Severity of injury u Morphology of injury ( base on CT scan )

13. Classification of Head Injury Mechanism of injury – Blunt: automobile collision, fall & assault – Penetrating: gunshot wounds, other penetrating injuries

14. Classification of Head Injury Severity – Coma:GCS sore =< 8 – Mild:GCS score 14 ~ 15 – Moderate:GCS score 9 ~13 – Severe:GCS score 3 ~ 8

15. Classification of Head Injury Morphology of Injury – Skull fractures – Intracranial lesions

16. Skull fractures u Vault: linear / stellate, depressed / nondepressed, open / close u Basilar (diagnosed by CT bone window): raccoon eyes, Battle’s signs (retroauricular ecchymosis), CSF leakage and 7th nerve palsy

17. Intracranial Lesions u Focal lesions u Diffuse lesions

18. Intracranial Lesions Focal lesions: u Epidural hematoma: – most due to tearing of the middle meningeal artery – prognosis is usually excellent ( underlying brain injury is limited ) – CT: biconvex or lenticular in shape – Pitfalls: classical lucid interval and ‘talk and die’

19. Intracranial Lesions Focal lesions u Subdural hematoma: – brain damage much more & prognosis is much worse than EDH – tearing of a bridging vein

20. Intracranial Lesions Focal lesions u Contusions and intracerebral hematomas: – most occur in the frontal & temporal lobes – always seen in association with SDH

21. Intracranial Lesions Diffuse injuries – Mild concussion: temporary neurologic dysfunction, confusion & disorientation without or with amnesia – Classic cerebral concussion: 1.Transient & reversible loss of consciousness, returns to full consciousness by 6 hrs. 2.No sequelae other than amnesia for the events 3.post-concussion syndrome: memory difficulties, dizziness, nausea, anosmia & depression

22. Intracranial Lesions Diffuse injuries: – Diffuse axonal injury ( DAI ) 1.prolonged postraumatic coma that is not due to a mass lesion or ischemic insults 2.usually having decortication or decerebation posture 3.autonomic dysfunction: hypertension, hyperhidrosis & hyperpyrexia

23. Assessment of Head injury History u Mechanism of injury u Pre and post injury status u Document / communicate u Reassess

24. Assessment Vital Signs u Identifies neurologic & systemic status u Presume hypotension due to hypovolemia, not head injury

25. Minineurologic Exam Purpose u Determine severity of brain injury u Detect deterioration u Categories injuries

26. Minineurologic Exam u Level of consciousness - GCS – eye opening – verbal – motor u Pupil u Motor lateralization ( mass lesion )

27. Minineurologic Exam Pupils u Equality u Briskness of response u Anormal: >1 mm difference in size

28. Minineurologic Exam Extremity Movement u Equality u Pain response u Lateralized weakness - mass lesion

29. Minineurologic Exam u Repeat & compare u Detect deterioration u initiate treatment u Neurosurgical Consultation

30. Minineurologic Exam Don’t presume altered status due to alcohol / drugs ingestion

31. Diagnostic Procedure u CT: – be obtained in all head -injury patients ( ideally ), especially there is a history of more than a momentary loss of consciousness, amnesia or severe headaches u C-Spine u Alcohol level & urine toxic screen u Skull X-ray: – penetrating head injury or when CT scan is not immediately available

32. Head injury Management Management Goals u Establish diagnosis u Assure brain metabolism & prevent secondary brain injury u Consult Neurosurgen early or early transfer

33. Head injury Management Management of Mild head injury u Normal CT : 1.Brought back to ER if need ( Head- injury warning discharge instructions ) 2.No companion ==> Admission or observe at ER u Abnormal CT : Admission

34. Head-injury Warning discharge Instruction u Drowsiness or increasing difficulty in awaking patient ( Awaken patient every 2 hrs ) u Nausea or Vomiting u Convulsion or fits u Bleeding or Watery discharge from the nose or ear u Severe headache u Weakness or loss of feeling in the arm or leg u Confusion or strange behavior u One pupil larger than the other, double vision or visual disturbance u Very slow or very rapid pulse, or an unusual breathing pattern

35. Head injury Management Management of Moderate Head Injury u GCS 9 ~ 13 u All need brain CT u All need to be admitted, even if CT scan is normal

36. Head injury Management Management of Severe Head Injury u GCS 3 ~ 8 u Prompt diagnosis & treatment is of utmost import ( wait and see = disastrous ) u Primary survey : Cardiopulmonary stabilization be achieved rapidly u Secondary survey : >= 50 % had additional major systemic injury u Minineurologic Examination : reliable minineurologic examination prior to sedating or paralying the patient

37. Medical Therapies for Head Injury Goal: To prevent secondary damage to an already injuried brain

38. Medical Therapies for Head Injury u Intravenous Fluid: – 1. Keep euvolemic status, dehydration is more harmful ( vital signs stable ) – 2. Not to use hypotonic or glucose- containing fluids u Hyperventilation: – 1. Keep PaCO 2 at 25~30 mmHg when the presence of raised ICP – 2. PaCO 2 CBF )

39. Medical Therapies for Head Injury Mannitol: u Indication: – 1. Comatous patient who initially has normal, reactive pupils, but the develops pupillary dilatation with or without hemiparesis – 2. Patient with bilaterally dilated and nonreactive pupils who are not hypotensive u Dose ( bolus ) : 1 g/Kg u Lasix : Be used in consultation with a neurosurgeon

40. Medical Therapies for Head Injury u Steroid : – Not demonstrated any beneficial effect u Anticonvulsants – High incidence of Late epilepsy: 1. Early seizure occurring within the first week 2. An intracranial hematoma 3. Depressed skull fracture – phenytoin reduce the incidence of seizure in the first week of injury but not thereafter

41. Restlessness u Identify etiology: – Pain – Hypoxia or shock u Correct cause: – Analgesics / Sedatives – Ventilation / Treat shock

42. Summary u In a comatose patient, secure & maintain airway ( endotracheal intubation ) u Moderately hyperventilation, keep PaCO 2 at 25~35 mmHg u Treat shock aggressively u Resuscitate with normal saline or Ringer’s lactate ( avoid hypotonic or glucose-containing fluid ) u keep euvolemic status

43. Summary u Avoid the use of long-acting paralytic agents u Perform a minineurologic examination after stabilizing the blood pressure and before paralying the patient u Exclude cervical spine injury u Contact a neurosurgeon as early as possible u Frequently reassess the patient’s neurologic status