Brain Death

Links:

Update: Determining Brain Death in Adults

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.
    • Angiography is gold standard. Nuclear medicine test is most commonly used. EEG and TCD are unreliable.

Organ Procurement

  • By law, physicians are to notify LOPA 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.
Scroll to Top