Severe traumatic brain injury

8) following head trauma with either


  • Significant mechanism of injury (fall from height, high speed MVC), or
  • Significant physical examination findings (depressed skull fracture, facial trauma, scalp lacerations).

  • Severe TBI patients have a very high mortality rate. In the United States, there are 52 000 deaths each year from head trauma. Unlike other conditions, severe TBI often affects the young and able-bodied. Worldwide, it is the leading cause of mortality and disability in children and young adults.
  • Always consider reversible causes of altered mental status in the trauma patient: toxicological, infectious, pulmonary, cardiac, hypoglycemia.
  • The goals of early resuscitation should focus on identifying and treating the initial injuries and limiting the negative cascade of secondary injuries such as hypotension and hypoxia.
  • All patients with suspected severe TBI need an emergent computed tomography (CT) scan of the brain to identify hemorrhage immediately following initial stabilization.
  • 10% of severe TBI patients have concomitant c-spine injury.
  • See Table 7.1 for common patterns of TBI.


      Table 7.1. Common traumatic brain injury patterns







      Management


      Glasgow Coma Scale


      • Calculate concurrently with other resuscitation efforts.
      • Preferably before administration of any sedative or paralytic medications.
      • Also perform pupillary reflex examination.







      Add the total of each column.


      Airway


      • Early intubation is indicated in all severe TBI patients.
      • Maintain c-spine precautions until clearance is possible (i.e., rigid cervical collar, logroll the patient, do not allow them to flex or extend the neck).

      Rapid sequence intubation (RSI)


      • The cerebral perfusion of severe TBI patients is tenuous, and first pass intubation is critical.
      • The RSI medications should include a sedative and a paralytic agent with these objectives:

        • Maintenance of hemodynamic stability and CNS perfusion
        • Maintenance of adequate oxygenation
        • Prevention of increases in intracranial hypertension
        • Prevention of vomiting and aspiration.

      • Pretreatment may help minimize increase in intracranial pressure (ICP) during intubation (no strong evidence to support its use and not universally used):

        • Lidocaine (1.5 mg/kg) intravenous push 3 minutes prior to induction
        • Fentanyl (3 micrograms/kg) slow intravenous push 3 minutes prior to induction, after lidocaine.

      Induction agents


      • Etomidate (0.3 mg/kg) has been demonstrated to be hemodynamically stable and not increase ICP.
      • Ketamine (1.5 mg/kg) should be considered if hypotensive or normotensive (avoid if the patient is already hypertensive).

      Paralytic agents


      • Rocuronium (RSI dose 1.2 mg/kg), onset of action 45–60 seconds.
      • Succinylcholine (1.5 mg/kg IV), onset of action 45–60 seconds (avoid in patients with crush injuries).
      • Vecuronium (0.1–0.2 mg/kg), onset of action 60–90 seconds.

      Breathing


      • Avoid hypoxemia and hyperoxemia (goal pulse oximeter of 95%).
      • Monitor with quantitative end-tidal PaCO2.
      • Maintain PaCO2 levels of 35–38 mmHg.

      Circulation


      • The goal is to maintain blood flow to the brain. The important measure is cerebral perfusion pressure (CPP), as opposed to systolic blood pressure (SBP). CPP = MAP − ICP. Systemic hypotension causes a decrease in CPP and must be avoided. If someone has increased ICP they need a higher blood pressure to maintain cerebral perfusion.
      • 500 mL to 1 L boluses of isotonic crystalloid should be given to maintain SBP >90.

      Intracranial pressure


      • Intracranial pressure is normally U+226415 mmHg.
      • Traumatic causes of increased ICP:

        • Intracranial mass lesions (hematomas)
        • Cerebral edema (acute hypoxic ischemic encephalopathy, large cerebral infarction, severe traumatic brain injury)
        • Obstructive hydrocephalus.

      • See the table below for clinical signs of increased ICP and impending herniation.















      Clinical signs of increased ICP and impending herniation
      Unilateral or bilateral fixed and dilated pupil(s)
      Decorticate or decerebrate posturing
      Cushing reflex: bradycardia, hypertension, and/or respiratory depression
      Decrease in GCS >2



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    • Feb 17, 2017 | Posted by in CRITICAL CARE | Comments Off on Severe traumatic brain injury

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