- Patients with brain injury from: 1) non-mechanical mechanisms (e.g., drowning); 2) choking, primary asphyxiation, or strangulation; 3) environmental injury (e.g., hyperthermia); 4) poisoning (e.g., drug overdose, carbon monoxide, insecticides); 5) intracranial hemorrhage of non-traumatic origin; 6) other non-traumatic, acute neurological emergencies (e.g., bacterial meningitis).