This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
Which of the following is not a cause of secondary brain injury? 
Select and explain. 
A. Hypocapnea, B. Hyperglycemia, C. Hypoxia, D. Hypotension
A: Hypocapnea
Answer: A: Hypocapnea 
Explanation: 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)