375.2 🩺 國考版

375.2.1 高頻考點

375.2.1.1 Brain Death Criteria

  1. Irreversible coma of known etiology
  2. Absent brainstem reflexes
  3. Apnea (apnea test)

375.2.1.2 Confounders to Exclude

  • Hypothermia (< 36°C)
  • Drug intoxication/sedatives
  • Neuromuscular blockade
  • Metabolic/electrolyte disturbance
  • Severe hypotension
  • Severe endocrine

375.2.1.3 Apnea Test

  • Pre-oxygenate 100% × 10 min
  • Baseline PaCO2 35-45
  • Disconnect, observe 8-10 min
  • Positive: PaCO2 ≥ 60 OR ↑ ≥ 20 from baseline, no breathing

375.2.1.4 Brainstem Reflexes (Must All Be Absent)

  • Pupillary
  • Corneal
  • Oculocephalic (doll’s eyes)
  • Oculovestibular (cold caloric)
  • Gag
  • Cough
  • Facial grimace
  • Jaw jerk

375.2.1.5 Ancillary Tests

  • EEG: electrocerebral silence
  • Cerebral blood flow: angio, HMPAO, CTA, TCD
  • Use if apnea contraindicated or confounders persist

375.2.1.6 Spinal Reflexes

  • Can persist after brain death
  • Lazarus sign
  • DO NOT preclude diagnosis

375.2.1.7 DOC Spectrum

  • Coma
  • UWS (vegetative state)
  • MCS
  • Locked-in (preserved awareness)
  • Akinetic mutism

375.2.1.8 UWS Prognosis

  • Persistent: 1 month
  • Permanent (non-traumatic): 3 months
  • Permanent (traumatic): 12 months

375.2.1.9 MCS vs UWS

  • MCS has inconsistent signs of awareness
  • Better prognosis
  • Command following, visual tracking

375.2.1.10 Locked-In Syndrome

  • Ventral pontine lesion (basilar artery occlusion)
  • Preserved vertical eye movements + blinking
  • Awareness intact

375.2.1.11 Covert Consciousness

  • Apparent UWS but evidence of awareness on advanced testing
  • fMRI/EEG paradigms
  • Important to detect

375.2.2 Pediatric Considerations

375.2.2.1 2023 AAN Pediatric Brain Death

  • 2 separate examinations
  • 2 apnea tests
  • Interval depends on age:
    • 7 days - 30 days: 24 hr interval
    • 31 days - 1 year: 12 hr

    • 1 year: 12 hr (some institutions less)

  • Ancillary tests recommended in many cases

375.2.2.2 Newborns

  • Strict criteria
  • Term newborns ≥ 37 weeks gestation

375.2.3 Organ Donation Brief

375.2.3.1 DBD vs DCD

  • DBD: after brain death declaration
  • DCD: after cardiac death

375.2.3.2 Brain Death Maintenance

  • Hemodynamic support
  • Hormone replacement (thyroid, vasopressin, steroid)
  • Optimize organ function

375.2.3.3 Family Communication

  • Brain death = death
  • Mechanical ventilation temporarily maintains organs
  • Cultural/religious considerations