Review the visual pathways and the defects associated with lesions at the various locations. The optic nerve would leave complete loss of vision in the one eye, while the optic tract would give you a homonymous hemianopia. The brainstem is not involved in transmitting visual information.

Profound shock (usually stages 3 and 4) are indications for intubation. In stage I shock, there is not an absolute requirement to intubate, although a proactive person should be prepared for the patient's condition to worsen, and intubation to be necessary later.

Oxygen saturation of <90% on 100% O2 is a reason to intubate, as is increasing PCO2. Patients with GCS scores <8 should be intubated as well. You should also anticipate intubating patients who have sustained trauma, possible inhalation injury, severe heart failure, asthma, or conditions that lead to the development of ARDS or Acute Lung Injury.