Brain death, death by neurological criteria and organ donation: Viva

Branch 1: The definition and the prerequisites

The candidate should define brain death as the irreversible cessation of all function of the entire brain including the brainstem, and state that it is one of two legal definitions of human death alongside circulatory death, so a declaration of brain death is a declaration of death in full. A strong candidate distinguishes the whole-brain formulation used in the United States from the brainstem formulation used in the United Kingdom, and notes that the bedside determination is identical across the two. ^[4]

If the examiner presses on the prerequisites, the candidate should state that no testing begins until a known and irreversible catastrophic cause is established and every reversible confounder is corrected. The candidate should list the confounders in turn: the hypothermia, excluded by a core temperature of at least 36 degrees Celsius, the hypotension, excluded by a blood pressure normal for the age, the central nervous system depressant drugs and the barbiturates, cleared for at least five half-lives and confirmed at a therapeutic-zero level, the metabolic and endocrine and acid-base derangements, corrected to the normal range, and the neuromuscular blockade, excluded with a train of four. A single uncorrected confounder invalidates the examination. ^[1][3]