What is the most common cause of airway obstruction in unconscious patients?

The most common cause of airway obstruction in unconscious patients is the tongue falling back into the oropharynx. In an unconscious state, muscle tone decreases, which can lead to the positioning of the tongue in such a way that it obstructs the airway. This mechanism is especially relevant given the anatomy of the upper airway and the fact that the tongue is the largest structure within the oropharynx. When a patient is unconscious—due to factors such as sedation, overdose, or injury—the natural reflexes and muscle control that would typically keep the airway open are compromised. As a result, the tongue can easily fall backwards, obstructing airflow and making it difficult for the patient to breathe.

Addressing other potential causes of airway obstruction, while foreign body obstruction can certainly occur, it is less common in unconscious patients compared to the impact of the tongue. Swelling in the airway and fluid accumulation in the lungs may also contribute to airway issues, but these instances are generally related to specific pathological conditions and not primarily responsible for routine airway obstruction in unconscious patients. Thus, the tongue's position is the predominant cause of the airway concern in this scenario.