Final answer:
In the case of an unresponsive 19-year-old male with a severe airway obstruction after abdominal thrusts, you should check for a pulse, call for help, and begin CPR, focusing on high-quality chest compressions between T4 and T9.
Step-by-step explanation:
If a 19-year-old male with a severe airway obstruction becomes unresponsive after you were performing abdominal thrusts, you should immediately call for help and begin CPR. Once the individual is on the ground in a supine position, check for a pulse and look for any signs of breathing. If there is no pulse or breathing, start with chest compressions following the CPR guidelines which include compressing the chest at least 5 cm deep at a rate of 100 compressions per minute. Proper positioning of the hands on the sternum to perform CPR is critical, and this should be done between the lines at T4 and T9. If trained and equipped, and if breaths are required, you can force air into the lungs of an unconscious person using a device like a balloon connected to a valve mask. Remember, performing high-quality chest compressions is the priority in CPR.