When should rapid sequence intubation (RSI) be initiated?

Rapid sequence intubation (RSI) should be initiated when airway management is necessary due to a compromised airway or inadequate ventilation. This is a critical situation where a patient's ability to breathe effectively is threatened, whether due to an obstructed airway, reduced level of consciousness, or other factors that impair respiratory function. Initiating RSI in these circumstances allows for the secure placement of an endotracheal tube, which can provide a clear airway and facilitate adequate oxygenation and ventilation, critical for patient stabilization.

In contrast, performing RSI on patients who are fully conscious, as suggested in one of the other options, may lead to complications such as the risk of aspiration and does not address a critical need for airway management. Similarly, in cases of severe hypoglycemia, while immediate treatment is essential, that condition itself does not inherently warrant the need for RSI unless it concurrently affects the patient's ability to maintain airway patency. Finally, initiating RSI when a patient shows signs of improvement would be inappropriate, as RSI is typically reserved for scenarios where immediate intervention is vital to protect the airway and ensure profound stabilization.