Final answer:
The first action you should take is to establish an open airway and initiate rescue breathing. Once the airway is open, you should assess and manage the circulation. Immediate medical attention and trauma alert should be activated.
Step-by-step explanation:
In this scenario, the first action you should take is to establish an open airway and initiate rescue breathing. The unresponsiveness and low respiratory rate (RR 5) indicate a severe compromise in breathing. By providing rescue breathing, you can help oxygenate the boy's blood and improve his oxygen saturation (spo2%).
Once the airway is open and rescue breathing is initiated, you should then assess and manage the circulation. The high heart rate (HR 170), low systolic blood pressure (SBP 60), and low oxygen saturation (spo2 75%) suggest poor perfusion. You may need to administer fluids, initiate chest compressions, or consider other interventions to improve blood flow.
It is important to note that this situation is an emergency, and immediate medical attention is required. The boy's condition indicates a serious injury, likely from the multi-system trauma suffered in the MVC. Therefore, it would be appropriate to activate a trauma alert or seek specialized medical assistance as soon as possible.