ICU . What do they do stabilise patients.?

This information is for a literary project I'm working on. What decides is a patient is sent to ICU?
Are all ICU patients intubated?
If a patient is given benzodiazepines to sedation them, can they still have convulsions and if so, what would be given to stop the convulsions?
What kind of cardiac medication is given to counteract hypotension?

ICU or Intensive Care Unit, it's for patients that need constant monitoring because they are in critical condition. Patients in ICU usually come straight from surgery and are usually intubated in the field or in the ER, then they go to a respirator. If a patient is given benzos for sedation and they convulse then the dose may not be high enough, or they may just need another dose. most Dr's don't like to give anything too strong to critical patients especially if they have had any brain trauma. Hypotensive patients in ICU usually need nothing more than more fluids pushed, typically due to blood loss during trauma or surgery. sometimes more blood, but usually just fluids. ICU is all about monitoring to make sure they don't crash. Hope I answered all your questions to your satisfaction.

in many hospitals, i have seen that not required patients, i mean fully fit, has been kept in the icu as the fees of the icu is sometimes paid by the company,

ICU stands for Intensive Care Unit. Only very ill people are sent there. The severity of the patients' health determines if they go there, and no; not all patients in ICU are intebated.