A semi-conscious trauma patient with a suspected cervical spine injury has a significant amount of blood in her mouth. What should you do?

In the scenario described, performing a jaw thrust is the most appropriate immediate action. A jaw thrust maneuver is a technique used to open the airway in a patient who may have a neck injury, especially when cervical spine injury is suspected. This method minimizes movement of the cervical spine, reducing the risk of exacerbating any potential spinal injuries.

The presence of significant blood in the patient's mouth suggests the need for careful airway management, as it could lead to airway obstruction. The jaw thrust helps to establish an open airway and allows for better ventilation without further compromising the patient's cervical spine.

Other actions, such as initiating airway suctioning, although important, should only be performed after the airway is opened. Chest compressions and providing rescue breaths are not appropriate in this particular context, as the priority is to secure and maintain the airway first, considering the complex nature of the patient's injuries.