Final Answer:
Hypocapnia in a patient with severe traumatic brain injury causes D) cerebral vasoconstriction.
Step-by-step explanation:
Hypocapnia and Traumatic Brain Injury: Hypocapnia refers to a condition of reduced carbon dioxide levels in the blood. In the context of severe traumatic brain injury, the respiratory system may overcompensate, leading to lower carbon dioxide levels.
Cerebral Vasoconstriction: The decrease in carbon dioxide can result in cerebral vasoconstriction, where the blood vessels in the brain narrow. This constriction reduces blood flow to the brain.
Impact on Brain Perfusion: In a patient with traumatic brain injury, maintaining adequate cerebral perfusion is crucial for preventing further damage. Cerebral vasoconstriction due to hypocapnia reduces blood supply to the injured brain tissue, potentially worsening the patient's condition.
Hypocapnia in a patient with severe traumatic brain injury causes D) cerebral vasoconstriction.