The term "lifeline" has been being used on news programs on TV, in magazines, etc. for some time now (probably since the Hanshin-Awaji Quake) and most folks who watch TV, read papers/mags should be familiar with it. Even my mother uses it.
I do find it sort of funny the way a lot of the people, especially the young ones, handle these interviews so well (almost too well). Back when I was younger, being/speaking on TV was a big deal, and I'd imagine most people, including myself, freezing up and getting tongue-tied the moment the red light flashes on the camera, but the kids today answer the questions like the pros. Those taken-straight-from-the-JPOP-lyrics phrases like "ナスv窶堋「窶堙ー窶愿坂?堋ッ窶堙ゥ", "(窶儂窶堋ゥ窶堙?ナ智窶堋ェ窶堙ゥ" andツ "ナ陳ウ窶ケC窶堙ー/ニ恥ニ陳渉ー窶堙ー窶堙?窶堙ァ窶堋、" come out of them so naturally and effortlessly. It makes me chuckle every time. ツ