Brain death definition
- Brain death is the irreversible loss of all functions of the brain, including the brainstem
- The three essential findings in brain death are coma (unresponsiveness), absence of brainstem reflexes, and apnoea
- underlying diagnosis (e.g. SAH, TBI, severe hypoxic brain injury)
- duration of current neurological state
- exclude reversible causes
- perform brain death examination
- no sedation
- last dose of NMB?
- nimodipine (likely SAH)
- no spontaneous breaths
- raised ICP
- bradycardia and hypertension (Cushing’s response)
- exclude hypothermia
- ICP monitor and duration (calibration drift after 5 days)
- EVD with blood-stained CSF
- cooling blanket or cooling machine (suggests post-cardiac arrest; could also be TBI with ICP management)
- high urine output (DI)
QUESTION SPECIFIC EXAMINATION
- note requirements (4h observation, then independent examination by 2 experienced clinicians)
- check preconditions
- request equipment
- cotton bud
- tongue depressor
- ice cold water and 20mL syringe
- peripheral nerve stimulator
- Mapleson C ciruit (apnea testing, allow PEEP and observe for respiratory effort) or oxygen catheter
- laryngoscope (test gag with direct vision)
- perform ‘train of four’ at 40 mV (likely will be told result)
- perform GCS
- test pain response
- supra-orbital ridges (CN5), TMJ (CN5), sternal rub (trunk) and a nail bed on each limb
- look for grimace (CN7)
- note that spinal reflexes do not preclude brain death
- test pupil response to light (CN2 and CN3)
- test corneal reflex (CN5 and CN7)
- test vestibulo-ocular reflex: (CN3,6,8): check ear canals, assistant holds eyelids open, 20 mL cold water into each ear canal with towel and kidney dish, observe for 60 seconds (oculo-cephalic reflex not part of Australian brain death testing)
- test gag with laryngoscope and cough with suction catheter (CN9, 10)
- test for spontaneous ventilation — FiO2 1.0 then passive oxygenation with Mapleson C circuit or O2 catheter in ETT with 2L/min; allow CO2 to rise to 60 mmHg with pH <7.3 (or 20 mmHg above baseline if COPD); expect rise of 3 mmHg/min in PCO2 unless high O2 flow
- 24 hour urine output (DI)
- UEC, ABG (normal electrolyte and metabolic state?)
- recent CT Head
- other neuro-imaging e.g. 4 vessel cerebral angiogram
- irreversible cause for coma?
- duration of neurological state?
- last dose of sedation or NMB?
- possibility of toxic cause?
- normal metabolic and endocrine status?
- “This person is brain because…” or
- “This person does not meet the preconditions for brain death testing…” or
- ” this person is not brain dead…
- DDX of fixed dilated pupils
- requirements for certification of brain death
- diagnosis of brain death in presence of cervical spine or severe facial injuries
- when to order a 4-vessel angiogram and role of radio-isotope imaging
- difference between brain death and similar states (e.g. locked-in syndrome, persistent vegetative state)
- how to discuss organ donation with the family
- management problems of the organ donor prior to donation
References And Links
- CCC — Brain Death
- CCC — Changes in Brain Death Consensus Statement
- CCC — Observations Compatible and Incompatible with Brain Death
- CCC — Coma-like syndromes
- CCC — Management of the organ donation patient
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health, a Clinical Adjunct Associate Professor at Monash University, and the Chair of the Australian and New Zealand Intensive Care Society (ANZICS) Education Committee. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of LITFL.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of two amazing children.
On Twitter, he is @precordialthump.