Increasing Intracranial Pressure leads to brain failure. Any patient with increasing ICP is considered SERIOUS and should be evacuated to definitive medical care as soon as possible.
You should anticipate a patient with increasing ICP will have a degrading mental status, and you will need to be prepared to manage their airway and temperature control. While they are able, make sure to manage hydration and calories. Try and push calories as a liquid as possible since these patients tend to vomit as they progress.
Early signs of increasing ICP are mental status changes while awake—confusion, irritability, disorientation, etc. The patient may complain of a severe headache. They may vomit. All patients get one “free” puke. If the patient starts persistent vomiting, the situation is serious.
As the swelling in the brain progresses, the patient will start degrading mentally. They may drop into verbal or pain responsiveness—or become completely unresponsive. They may have seizures. Their pupils may dilate. Expect changes to vital signs. If the patient is exhibiting these symptoms, the prognosis is not good.
You basically need to be prepared to give good basic life support or palliative care if transport and evacuation are not possible.