I had a similar experience when I was in hospital one time.
I had had trouble breathing and was put on the overnight observation ward, not only is this a very noisy ward [It's basically halfway house between A&E and intensive care or a normal ward] but you also get woken up every 2 hours regardless for themto check on you.
It was noisy but I managed to drift off eventually, and I was in the "green" section of the ward which was basically the "safe" bit, none of us were desperately ill and we were last priority, turns out however that it was a very busy night and that there were no beds left in the red, orange and yellow sections, just the one opposite me in the green section. This guy came in and he was just shouting in pain he was just saying "oooh oooh" and there were about four Doctors and three nurses running around him like crazy. This guy seemed [other than his physical symptoms] fine, since he could answer questions.
He smoked weed, daily, he didn't say how much. He smoked 60 cigarettes daily and drank 8 pints daily, about 20 on a weekend. He was only 32 but he sounded about 60. I couldn't see anything but I could hear more than I would have liked to. He had basically gone cold turkey the night before and he had therefore not smoked, drank or taken drugs [from what I gathered he took more than just weed] in about 24 hours, and his system was shutting down. All I could hear were people running round after him, hooking machines and taking blood and shouting questions and him shouting for help because he "couldn't see anyone there" when there were about 4 people surrounding him. It seemed like he was there for an hour, throwing up and shaking and falling off the bed and soiling himself and crying and shouting, but I bet it wasn't even ten minutes. He heart stopped, and they brought him back, it stopped again and they brought him back again and I remember feeling like I was in a movie, after they brought him back the third time he was rushed to intensive care. I never saw or heard about him again. He was such a wreck, I remember him saying "I thought the drink was killing me, not keeping me alive" and crying and crying and crying.
That experience, most of it heard rather than seen, has made me think of a lot of things. Life and death, for a start, and what a fine line there is between the two. I also have an immense respect for medical professionals and the amount of care and respect they show strangers, and the amount of time and sweat and effort they put into keeping us all well, I still can't believe how calmly they were all reacting to this disaster when I was almost in tears!! I could never imagine being so brave in such a critical situation.