Good to hear your grandfather's ok. Really impressed - the rate of spontaneous revival with ambulatory CPR alone is minimal (<1%, IIRC), while the overall survival is about 5% mean (ranging from <1% to about 30%, depending on many factors). Miracle indeed. Glad to hear he's alive and kicking.
Random Medicine Rant:
Back when it was first introduced, CPR had a much higher survival rating, owing to it only being used on people who would benefit most. Now a lot of people get it who would have a lower chance of responding to it in the first place (baseline respiratory issues, old age, etc.), and that's part of the low success rating (the other part being that it's not the most efficient method anyway, plus other factors like time until intervention). It's really only designed to support the body until better care (ventilation, particularly) can be established, as it only provides something like 25% of the body's normal circulation (but it's better than 0%!), so the faster you get care, the better.
I blame medical shows, most of which show something crazy like a 75%+ success rate! Screw you, ER. The hilarity of this is that NEJM even did a study on this in 1996!
Had a lady with a host of problems come in to the hospital effectively on her deathbed, but with a family who wanted everything heroic done. She crashed a few days in, and she got CPR. Imagine a 56 kg lady, with multi-organ-system-failure, dementia, and a host of other problems given chest compressions. Broke her ribs, barely got her back after 20 minutes of it, sent her to the ICU, and after a few days of life support (where she was completely non-coherent, having had effectively no circulation for 10 minutes), the family finally decided to "pull the plug", so to speak. I'm sure that was far, far worse for them and the patient than it could have been.
The worst part was that, while the lady had dementia, when she was still conscious before the crash, she was saying she wanted to die and not have any of that done, but because she had an appointed MPOA due to not being deemed mentally "fit", she had no control over the situation.
Cool enough, Lancet released a study early in 2011 that showed promise of a 50% increase in success (so from 6% to 9%) vs. conventional methods by using new methods and technology, but it's still a relatively small survival rate.
Point of the matter is that it's a holding technique until better care can be procured.
On an unrelated note: Firefox on my home computer will not load and keeps crashing, yet works fine on my work computer. Maybe I should never leave my office?
