Mr. L is a 35-year-old man who has a sudden, excruciating headache and collapses in his chair at dinner. At the emergency department, a CT scan reveals a subarachnoid hemorrhage. Mr. L is admitted to the intensive care unit for monitoring and supportive measures aimed at controlling the intracranial pressure. The next morning he is noted to be unresponsive, with non-reactive, mid-position pupils.

A 3½-year-old boy, M, is playing near the backyard pool under supervision of his babysitter. The caretaker goes into the house to answer the telephone. Upon returning, she discovers the child face down in the pool. The paramedic team arrives and finds the child's vital signs are absent. Basic life support is started, and the boy is taken to the hospital. He is resuscitated with intubation, ventilation, and intravenous epinephrine injection. The minimum documented duration of absent vital signs is 30 minutes. He is comatose and unresponsive, with spontaneous breathing, reactive pupils and intermittent generalized seizures.