In a head-injured patient with signs of cerebral edema, hyperventilation should be used only cautiously to achieve which goal?

• A. Decrease elevated intracranial pressure
• B. Increase blood pressure
• C. Decrease heart rate
• D. Improve oxygen saturation

Answer: (A)

Hyperventilation lowers PaCO2, which causes cerebral vasoconstriction and reduces cerebral blood volume. In a head-injured patient with cerebral edema, the immediate aim is to decrease elevated intracranial pressure to prevent herniation and preserve cerebral perfusion. Because this vasoconstriction can also lower cerebral blood flow and risk ischemia, hyperventilation is used only as a temporary, targeted measure to rapidly reduce ICP during acute deterioration—not as a long-term strategy. Other goals like raising blood pressure, altering heart rate, or directly improving oxygen saturation aren’t achieved by hyperventilation and are addressed with other interventions.