Brain Death

LITERATURE

Coma v. Brain Death

  • Coma –persistent unresponsiveness due to abnormal functioning in reticular activating system and/or both cerebral hemispheres. At least brain stem reflexes are present
  • Brain Death – complete irreversible lack of any brain function, including brainstem. Renders life support useless.
  • Medical conditions that mimic brain death —locked in syndrome, hypothermia, Guillain-Barre syndrome, drug intoxication

Brain Death Exam

  • Rule out/correct confounding medical conditions such as severe electrolyte derangements, acid base, or endocrine abnormalities
  • Pt is normothermic and normotensive
  • There is no drug intoxication, poisoning, or neuromuscular blocking agents which may confound neurologic assessment
  • CT scan is consistent with severe brain injury.
  • PATIENT HAS NO BRAINSTEM REFLEXES
    • Absence of motor response ► press on supraorbital nerve or condyles of temporomandibular joints (afferent CN 5, efferent CN 7)
    • Pupillary light reflex (A: CN2, E: CN 3)
    • Corneal reflex – use drop of normal saline into each eye or cotton swab to cornea (A: CN 5, E: CN 7)
    • Cold caloric testing –tilt head up 30 degrees, then irrigate each tympanum w/ 50 cc of ice water. Negative test (absence of reflex) is when the eyes do not deviate towards cold stimulus [ A: CN 8, E: CN 3, CN 6]
    • Gag reflex- move endotracheal tube side to side gently. (A: CN 9, CN 10)
    • Cough reflex- introduce suction catheter into trachea (CN 10)
  • Apnea Test
    • Pre-requisites
      • Core temperature > 36.5 C
      • SBP > 90 mmHG
    • If patient requires high dose vasopressors, high PEEP or FiO2 consider different confirmatory test
    • Pre-oxygenate patient for 10 minutes on FiO2 100%, obtain an ABG for PCO2 level
    • Disconnect the ventilator, insert suction catheter with thumb hold closed to level of carina and deliver O2 flow rate 6 mL/min
    • Expose chest and watch for any respirations x 10-15 minutes, watch VS and titrate vasopressors as needed.
    • Check ABG: if PaCO2 > 60 mmHg or increases > 20 mmHg – Apnea test is positive confirming brain death.
  • Confirmatory tests
    • Must be done if any part of the clinical exam cannot be completed.
    • Angiography is gold standard. Nuclear medicine test is most commonly used. EEG and TCD are unreliable.

Organ Procurement

  • By law, physicians are to notify state donation centers if the patient is GCS is 5 or less. Treating physicians should NOT discuss organ donation with the family. Doing so decreases the likelihood of donation.  However, if family brings it up, general statements can of course be made with the statement that an entity outside of the acute hospital setting will be in contact with them. 

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