You bought his family some time to say goodbye mate we all know if its a cardiac arrest when you get called you dont really stand a chance. I had a similar job myself the other week ( im a community first responder not an ambo ) - Got called to a 37 year old male cardiac arrest on my arrival CPR in progress by a neighbour (nurse) put the AED on but no shock advised started work on him after a few mins the FRU turns up and he tubes him and gets on with the drugs. The crew then turn up as well and eventually we get a rythum on the monitor although he still isnt breathing we move him to the ambo and the crew take him away i understand he died a few days later. The thing that really gets me is as first response on scene all the family were there the kids stood in the bedroom door the wife absolutely distraught crying for hewr husband not to leave her, you divorce yourself from this at the time but its afterward it hits you.