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

This boy has a catastrophic and irreversible brain injury from the hypoxic ischaemic encephalopathy, and the team is right to consider the determination of brain death. The cause is known and irreversible, the imaging shows the marked cerebral oedema, and the intracranial pressure could not be controlled, so the prerequisite of a devastating structural cause is met. The confounders must now be formally excluded before any neurological testing, the examination and the apnoea test performed by two clinicians, and the determination made across the two evaluations separated by the observation period. [3]

Question 1 (10 marks)

Outline the prerequisite checks and the bedside brainstem reflex examination you would perform in this child before the apnoea test, justifying each step. [1]

A full-mark answer states the prerequisites in turn, then performs the brainstem reflex examination with the findings that confirm the determination. [1]

The prerequisites (5 marks). The cause is known and irreversible, namely the hypoxic ischaemic encephalopathy with the cerebral oedema and the refractory intracranial pressure, confirmed on the imaging and the course. The core temperature is 37.0 degrees Celsius, which is at least 36 degrees Celsius, so the hypothermia confounder is excluded. The systolic blood pressure is 98 mmHg on low-dose noradrenaline, which is normal for a 3-year-old, so the hypotension confounder is excluded. The sedation has been off for over 48 hours, which is well beyond five half-lives for the common agents, and a barbiturate level is checked and confirmed therapeutic-zero. A drug and a toxin screen are sent, the electrolytes, glucose, calcium and the blood gas are checked and corrected, and a train of four confirms the full neuromuscular recovery. [1]

The brainstem reflex examination (5 marks). The boy is in a deep coma with a Glasgow Coma Scale of 3, with no eye opening, no verbal response, and no motor response to any stimulus. The pupils are fixed and dilated at the midposition, often four to nine millimetres, with no reaction to a bright light. The corneal reflex is absent to a touch of the cornea. The oculocephalic reflex, the doll's eye manoeuvre, is absent and is omitted if the cervical spine is not cleared. The oculovestibular reflex is absent to the cold caloric stimulus. The gag and the cough reflexes are absent to the pharyngeal and the tracheal suction. Each finding is recorded with the time and the names of the two independent senior clinicians, neither of whom is part of the transplant team. [4]