CICM SAQ 2010.2 Q12

Questions

12.1. Outline the preconditions that must be met in order for accurate determination of brain death by clinical examination.

12.2. When the preconditions for the clinical determination of brain death cannot be met, what imaging modalities are recommended to determine absence of intracranial blood flow? What findings in each test confirm brain death?


Answers

Answer and interpretation

12.1. Outline the preconditions that must be met in order for accurate determination of brain death by clinical examination.

  • Evidence of sufficient intracranial pathology or a known cause of coma e.g.; traumatic brain injury, intracerebral haemorrhage, hypoxic-ischaemic encephaloopathy
  • normothermia (temperature > 35°C);
  • normotension (as a guide, systolic blood pressure > 90 mmHg, mean arterial
  • pressure (MAP> 60 mmHg in an adult);
  • exclusion of effects of sedative drugs (self-administered or otherwise) — the time taken for plasma concentrations of sedative drugs to fall below levels with clinically significant effects depends on the dose and pharmacokinetics of drugs used, and on hepatic and renal function. If there is any doubt about the persisting effects of opioids or benzodiazepines, an appropriate drug antagonist should be administered;
  • absence of severe electrolyte, metabolic or endocrine disturbances— these include: marked derangements in plasma concentrations of glucose, sodium, phosphate or magnesium; liver and renal dysfunction; and severe endocrine dysfunction;
  • intact neuromuscular function— if neuromuscular-blocking drugs have been administered, a peripheral nerve stimulator or other recognised method (e.g. electromyography) should always be used to confirm that neuromuscular conduction is normal;
  • ability to adequately examine the brain-stem reflexes— it must be possible to examine at least one ear and one eye; and
  • ability to perform apnoea testing— this may be precluded by severe hypoxic respiratory failure or a high cervical spinal cord injury.

12.2. When the preconditions for the clinical determination of brain death cannot be met, what imaging modalities are recommended to determine absence of intracranial blood flow? What findings in each test confirm brain death?


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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 and Clinical Adjunct Associate Professor at Monash University. 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.

| INTENSIVE | RAGE | Resuscitology | SMACC

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