Jeanette, et al,

My latest IFAK is much more of a trauma kit than a boo boo kit so have been adding chest vents, CAT TQs, Izzy bandages, Celox and the like. While researching I see many people carry the following as you do.

(2) Nasopharyngeal Airway w/ Lube, 28 Fr
(2) ARS Decompression Needle, 10 g x 3.25"

My question:
1. What situations are these used?
2. Does one need serious medical training to use? Or are there some video-training guides you recommend?