What are the reason that Rapid Sequence Intubation is used?

In recent years, rapid sequence intubation (ie, fast sequence induction [RSI]) has become the technique of choice for emergent airway running and is a skill that all emergency physicians must master. Indications for intubation are discussed within other articles but include respiratory failure, altered mental status, cardiopulmonary arrest, and significant trauma.
RSI would be used anytime you necessitate to intubate somebody that is still conscious or still have a gag-reflex. For example, if somebody has severe facial burns, you would suspect their airway might start to swell and impair their breathing. But the patient might still be conscious, so you would enjoy to use RSI for them.