If a patient is experiencing arterial blood with a ph below 7.35, this condition is know as

"Acidosis" is going to be your answer. When something drops below the brains comfortable pH its known as Acidosis but when it is above alkaliosis. Acidosis can be caused by such things as Metabolic processes or ketones Also we are constantly in a state where we are dropping below, which makes our brain require us to breath CO2 out to maintain homeostasis.