When using Mannitol to elevate ICP, what must you anticipate?

When using Mannitol to elevate ICP, what must you anticipate?

• A. Immediate hypernatremia
• B. Volume replacement due to osmotic diuresis
• C. Hypothermia risk
• D. No fluid changes

Answer: (B)

Mannitol lowers intracranial pressure by increasing plasma osmolality, drawing water out of brain tissue into the intravascular space. But it is also filtered by the kidneys and causes osmotic diuresis, leading to a substantial urine output and losses of intravascular volume. Because of this, anticipate the need to replace fluids to maintain adequate circulating volume and cerebral perfusion pressure. Monitor urine output, blood pressure, and electrolytes, and adjust fluids as needed to prevent hypovolemia while continuing to manage ICP. Hypernatremia and other electrolyte shifts can occur with fluid losses, but the immediate and most important expectation is volume replacement due to osmotic diuresis.

Mannitol lowers intracranial pressure by increasing plasma osmolality, drawing water out of brain tissue into the intravascular space. But it is also filtered by the kidneys and causes osmotic diuresis, leading to a substantial urine output and losses of intravascular volume. Because of this, anticipate the need to replace fluids to maintain adequate circulating volume and cerebral perfusion pressure. Monitor urine output, blood pressure, and electrolytes, and adjust fluids as needed to prevent hypovolemia while continuing to manage ICP. Hypernatremia and other electrolyte shifts can occur with fluid losses, but the immediate and most important expectation is volume replacement due to osmotic diuresis.