Which of the following is not a cause of secondary brain injury?

Secondary brain injury refers to the changes that evolve over a period of time (from hours to days) after the primary brain injury. It includes an entire cascade of cellular, chemical, tissue, or blood vessel changes in the brain that contribute to fuher destruction of brain tissue. It is caused by the following factors: Hypoxia Hypotension;Low cerebral perfusion pressure ICP >20 mmHg Hypercapnea Metabolic disturbance (hyperglycemia)