In an unconscious person, care of the airway takes precedence over an injury, including the possibility of a spinal injury.
With the casualty left in the position found, look to see if the airway is blocked by solids or fluids by opening the mouth without tilting the head back.
To clear the airway, the mouth should be opened and head turned slightly downwards to allow any obvious foreign material to drain.
If the airway becomes compromised during resuscitation, promptly roll the person onto their side and clear the airway. Once the airway is clear, reassess for responsiveness and normal breathing. Restart resuscitation if necessary.
For an unresponsive adult or child, open the airway using the head tilt-chin lift. For an infant, open the airway by placing the head in the neutral position and support the jaw from falling back.