Which device is used to maintain an open airway without invading the tracheal lumen?

The device used to maintain an open airway without invading the tracheal lumen is a supraglottic airway device (SAD). This device is designed to sit above the vocal cords, therefore not entering the trachea directly. It provides a clear pathway for air to flow to the lungs while minimizing the risk of trauma or irritation associated with intubation.

SADs are particularly useful in scenarios where quick airway management is required, such as in emergency situations or in patients who are unable to cooperate for endotracheal intubation. They are often used in anesthesia practice because they can effectively secure the airway while also allowing for spontaneous ventilation.

In contrast, an endotracheal tube directly enters the tracheal lumen to secure the airway, which is not the aim in this scenario. An anesthetic mask serves to deliver anesthetic gases but does not maintain an airway on its own. Lastly, an anesthetic chamber is used for induction of anesthesia in small animals rather than for maintaining an open airway in a human patient. Each of these alternatives either directly invades the trachea or does not effectively secure the airway as a SAD does.