In TBI management, maintaining adequate MAP and CPP is primarily to prevent what?

• A. Secondary ischemia
• B. Hyperglycemia
• C. Dehydration
• D. Hypertension

Answer: (A)

Maintaining adequate MAP and CPP aims to preserve cerebral blood flow to the injured brain so it doesn’t undergo secondary ischemia after the initial trauma. CPP is defined as MAP minus ICP, so if blood pressure is too low or intracranial pressure is too high, CPP drops and brain tissue can be deprived of oxygen and nutrients. Keeping MAP at a level that maintains a sufficient CPP helps ensure perfusion of vulnerable brain tissue and reduces the risk of further injury beyond the primary injury.

Hyperglycemia, dehydration, and hypertension can worsen brain injury but are not the primary reason for targeting MAP and CPP. The main purpose here is to prevent ischemic damage from inadequate perfusion.