What should you do first when you find a semiconscious patient in a vehicle crash?

In the scenario of finding a semiconscious patient involved in a vehicle crash, the first priority is to ensure the patient's head and neck are stabilized. This is crucial because movement could exacerbate any potential spinal injuries that might have occurred during the crash. By directing a partner to apply manual in-line support of the patient's head, you are minimizing the risk of further injury while assessing the patient's condition.

Manual in-line support involves one rescuer stabilizing the patient's head and neck to prevent any movement, which is essential in situations where spinal injuries are suspected. This action provides a solid basis for any subsequent interventions, such as the application of further immobilization devices or extrication equipment.

While the other choices involve important steps in patient care, they should occur after the head and neck are stabilized. Sliding a long backboard under the patient or applying a cervical collar or extrication device typically follows the initial stabilization. Thus, the priority is on securing the cervical spine to prevent exacerbating potential injuries.