In the head-tilt/chin-tilt method, how is the thumb of the opposite hand used?

In the head-tilt/chin-tilt method, the thumb of the opposite hand is used primarily to depress the casualty's lower lip, if needed. This technique is crucial for maintaining an open airway, especially in cases where there may be blockage or obstruction due to the positioning of the tongue or soft tissues in the mouth. By pressing down on the lower lip, you can help facilitate a better airway opening, allowing air to pass through more freely.

This method is especially important when performing airway management for an unconscious casualty who may not be able to maintain their airway on their own. Effectively using the thumb in this manner helps ensure that the airway is kept open, which is essential for effective breathing and oxygenation.