If impending cerebral herniation is suspected, what should be administered?

The administration of 3 or 5% hypertonic saline is the correct choice when impending cerebral herniation is suspected because it helps to draw water out of the brain tissue, thereby reducing intracranial pressure. This is crucial as cerebral herniation can occur when there is increased pressure within the skull, causing brain tissue to shift from its normal position. The hypertonic saline creates an osmotic gradient that pulls fluid from the brain, countering the effects of edema and reducing the likelihood of herniation.

In contrast, isotonic solutions like normal saline or lactated Ringer's do not provide the same osmotic effect needed to alleviate increased intracranial pressure. D5W is a dextrose solution that lacks the necessary electrolytes to actively draw fluid out of brain tissues and could potentially worsen cerebral edema. Therefore, hypertonic saline is specifically indicated for managing suspected herniation due to its unique properties in manipulating fluid movement in the brain.