When might a rapid sequence intubation be indicated?

Rapid sequence intubation (RSI) is a critical procedure used in emergency settings to secure the airway of a patient who is unable to protect it on their own. The correct scenario for indicating RSI is when a casualty is unconscious and unable to maintain their airway. This situation arises in cases of severe trauma, significant head injuries, or other conditions where the patient's level of consciousness is compromised, making it impossible for them to fend off risk of aspiration or obstruction.

In this context, the procedure is performed to ensure that the airway is protected and that adequate ventilation can be achieved, which is essential for maintaining oxygenation and preventing hypoxia or further complications. Rapid sequence intubation allows for quick intubation while minimizing the time the patient is subject to the risks associated with airway compromise.

The other scenarios do not warrant the need for RSI, as a casualty who can maintain their airway, whether conscious and responsive or exhibiting only minor injuries, generally does not require the invasive procedure of intubation.