Tom - have you seen any of the stuff on reperfusion injury ? After an arrest cells do not die from ischaemia [at least not for some time] but are killed by aggressive oxygenation during the resuscitation effort - delivered of course by paramedics, HEMS, hospital staff, etc. This has led some authorties to advocate the use of cardio-respiratory bi-pass or hypothermia so that resuscitation is managed over a much longer time scale - apparently with very promising results when compared to traditional Resus Council methods. It certainly makes you think ?