Confusion and somnolence are neurological findings with severe hypoxemia, which shows that the hypoxemia has affected the patient's brain. The brain requires approximately 3.3 mL of oxygen per 100 grams of brain tissue per minute. Initially, the body responds to lowered blood oxygen by redirecting blood to the brain and increasing cerebral blood flow. Blood flow may increase up to twice the normal flow but no more. If the increased blood flow is sufficient to supply the brain's oxygen needs, then no symptoms will result. However, if blood flow cannot be increased or if doubled blood flow does not correct the problem, symptoms of cerebral hypoxia will begin to appear. These symptoms include restlessness, disorientation, headaches, lassitude, somnolence, confusion, delirium, blurred vision, etc.