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Management of Head Injury and Increased ICP. Nicole Baier , MD. Objectives. Review the: Epidemiology of head injury Various intracranial lesions Pathophysiology of increased ICP Management of head injury. Epidemiology. 2 cases per 1000 children per year Mild TBI: 82%
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Management of Head Injury and Increased ICP Nicole Baier, MD
Objectives • Review the: • Epidemiology of head injury • Various intracranial lesions • Pathophysiology of increased ICP • Management of head injury
Epidemiology • 2 cases per 1000 children per year • Mild TBI: 82% • Moderate to severe TBI: 14% • Fatal TBI: 5% (7000 deaths per year)
Etiology • Motor vehicle accidents • Falls • Non-accidental trauma • Sports injuries
Mechanisms of injury • Coup contusion • Adjacent to the site of injury • Brain accelerates against the fixed skull • Injury to parenchyma and blood vessels • Contrecoup contusion • Deceleration and recoil of the brain • Contralateral lesions
Epidural Hematoma • Classic: arterial origin, blood collects between skull and dura
Subdural Hematoma • Due to tearing of bridging veins, blood collects between dura and cortex
Subarachnoid hemorrhage • Disruption of small vessels on the cortex, occur along the falx, tentorium, or outer cortical surface
Mechanisms of Injury • Axonal injury: • Etiology: deceleration and shearing forces • Axonal swelling and degeneration • CT findings: • Normal initially • Delayed edema and petechial hemorrhages • Areas affected: • Basal ganglia • Thalamus • Deep hemispheric nuclei • Corpus callosum
Cerebral Edema • Cytotoxic Edema • Intracellular swelling • Due to cellular injury (DAI, hypoxia-ichemia) • Irreversible • Vasogenic Edema • Increased endothelial permeability • Therapy may prevent secondary injury • Seen with tumors, hematomas, infarcts, CNS infections • Interstitial Edema • Increased fluid in periventricular white matter • Etiology - hydrostatic CSF pressure
Monro-Kellie Doctrine • Intracranial Volume = Brain + CSF + Blood • Normal: • Brain 80% • CSF 10% • Blood 10%
Secondary injury • Bleed/edema increases intracranial volume → • Compress intracranial vessels → • Impairs blood flow → • Ischemia
Cerebral perfusion pressure • CPP = MAP – ICP • > 70 in adults • Children ????
What is Cushing’s Triad? • Hypertension, tachycardia, and dilated pupils • Hypotension, bradycardia, and posturing • Hypertension, bradycardia, and dilated pupils • Hypertension, bradycardia, and irregular respirations • Hypotension, tachycardia, and posturing
Cushing’s Triad • Hypertension • Bradycardia • Irregular respirations • Etiology: • When MAP < ICP, the hypothalamus stimulates sympathetic output • Increase in BP stimulates carotid baroreceptors and leads to a vagal response and bradycardia
A 2 year old boy is brought in by EMS. He was playing outside at home when a van backed into the driveway and ran over him. He was minimally responsive at the scene required bag-mask ventilation on the way in. You cannot elicit any response from him with painful stimulation. What is his GCS? • 2 • 3 • 4 • 5 • 6
Glasgow Coma Score • Eyes: Motor: • 4 opens spontaneously - 6 follows commands • 3 opens to verbal command - 5 localizes pain • 2 opens to pain - 4 withdraws to pain • 1 no response - 3 decorticate • Verbal: - 2 decerebrate • 5 oriented - 1 no response • 4 confused conversation • 3 inappropriate words • 2 incomprehensible sounds • 1 no response
Head Injury - grading • Mild: GCS ≥ 13 • Moderate: 9-12 • Severe: ≤8 Battle’s sign
You decide to intubate the child. Which of the following medications would be contraindicated in the given scenario? • Etomidate • Lidocaine • Fentanyl • Succinylcholine • Rocuronium
Management - Airway • Indications for intubation: • GCS ≤ 8 • Hypoxia • Loss of airway protective reflexes • Hypoventilation
Management - Airway • Rapid sequence intubation: • C-spine stabilization • Preoxygenation • Cricoid pressure • Induction Meds: • Thiopental – ICP ( cerebral metabolic rate) (may lower BP) or • Etomidate – ICP or • Benzodiazepine (may lower BP) + • Opiate for analgesia for injuries/ laryngoscopy • +/- Lidocaine (may blunt ICP assoc. with laryngoscopy) • Neuromuscular blockade
The child was successfully intubated after premedication with lidocaine, fentanyl, etomidate, and rocuronium. None of his labs are back yet. However, you decide to institute therapy for increased ICP. Which of the following therapies is indicated at this point? • Insertion of an ICP monitor • 3% normal saline bolus • Mannitol • Hyperventilation to CO2 of 25-30 • Therapeutic hypothermia
Management - Breathing • Try to keep CO2 normal (35-40) in patients with ICP • Risk of ischemia with hyperventilation • Hyperventilation used only for acute herniation
Management - Circulation • Maintain CPP to avoid secondary injury • Hypoxemia and hypotension each occur in 1/3 of patients • 1 episode of hypotension mortality 2x • Eval source of shock: • Internal bleeding? • Spinal cord injury?
Monitoring ICP • Indications: • GCS ≤ 8 • Neuro exam impossible (sedated, needs to go to OR for other injuries • Types: • Ventriculostomy most reliable, also therapeutic • Intraparenchymal – measurement drift • Subarachnoid, subdural, epidural – less reliable
Head positioning • Head midline • Head of bed to 30 degrees • Promote venous drainage
Sedation/ Analgesia • Benefits: • Decrease cerebral metabolic demands associated with pain and stress • Prevent spikes in ICP that may occur with suctioning, etc. • Facilitate mechanical ventilation • Anticonvulsant and antiemetic actions • Prevent shivering
Neuromuscular blockade • Benefits: • airway and intrathoracic pressure – facilitate cerebral venous outflow • Prevent shivering and posturing • Facilitate mechanical ventilation
Which of the following statements about the use of 3% normal saline is true? • Can only be given through a central venous line • Does not cause hypotension • Can only be used if serum osmolarity < 320 • Dose is 10 mL/kg • Can only be used if serum sodium is < 160
Hyperosmolar Therapy • 3% normal saline • Creates osmotic gradient • Decreases ICP and increases CPP • Used as boluses and/or continuous infusion • Goal: serum sodium > 150 • Max serum osm: 360 ??
Hyperosmolar Therapy • Mannitol • Mechanisms: • blood viscosity • creates osmotic gradient between plasma and brain • 0.25-1 g/kg doses • May repeat every 6-8 hours • Max serum osm: 320 • Adverse effects: • ATN • Hypovolemia
CSF Drainage • Ventriculostomy catheter
Which of the following statements regarding the use of pentobarbital is false? • Continuous EEG monitoring should be present when a pentobarbital coma is induced • The hallmark of pentobarbital coma is burst suppression • Pentobarbital causes profound myocardial depression • Pentobarbital use requires the approval of a neurologist • Pentobarbital reduces cerebral blood flow
Barbiturate Coma • Consider in: • Patients with refractory intracranial hypertension • Mechanisms: • Lowers resting cerebral metabolic rate by 50% • Decreases cerebral blood flow and cerebral blood volume • Neuroprotective: inhibits free radical-mediated lipid peroxidation, stabilizes membranes
Barbiturate Coma • Monitoring: • Burst suppression on EEG • Adverse effects: • Myocardial depression
Thermoregulation • Avoid hyperthermia • Increase cerebral metabolism • Inflammation • Lipid peroxidation • Excitotoxicity • Seizures
Surgical management • Decompressive craniectomy • Favorable surgical outcomes: • Within 48hrs of injury • Secondary GCS • Herniation • Unfavorable: • Unimproved GCS of 3 • Extensive secondary brain insults
Nutrition • Begin by 72 hours • Full replacement by 7 days • Patients with injury have increased resting metabolism expenditure • Increased mortality when head injured patients not fed within 1 week
Which of the following statements is true regarding the incidence of seizures in traumatic brain injury? • Antiepileptic medications decrease the incidence of late seizures • Children < 2yo have a lower risk of seizures • Most early seizures occur in the first 24 hours • Seizures do not affect the outcome of traumatic brain injury • All children with traumatic brain injury should be treated with antiepileptic medications until 1 week post-injury
Antiseizure prophylaxis • Posttraumatic seizures • Early: within 7 days • Late: after 7 days • Adverse effects: • Increase brain metabolic demands • Increase ICP • Lead to secondary brain injury
Antiseizure prophylaxis • Risk of seizures: • Early: • 20-39% incidence in severe TBI • risk if low GCS • < 2 yrs have 3x greater risk • Majority occur within first 24 hours
Antiseizure medications • Risk of seizures • Late: • 7-12% incidence in severe TBI • Increased incidence in depressed skull fracture • Relation to early seizures? • Prophylactic anticonvulsants do not affect incidence