We've only been dealing with type 1 diabetes since May of 2009 - but just recently had a stomach flu issue with my 12 year old t-1 son. (Christmas night actually) We also had just come from our 3 month endo visit a couple of weeks ago, and per their advice, ordered and received our first ever blood ketone meter with 12 free strips less than a week ago.
This blood testing really saved the day and allowed me to closely monitor the rise in his ketones when he had the stomach flu and could NOT "pee" for the regular foil wrapped ketone strips I have hundreds of - and allowed us to get to the hospital in time for "just" an IV and some Zofran. Then we got to go home with our every 3 hour monitoring of ketones/bg and to give him insulin - even if if was just for 4 oz of Sprite.
In any event - if the blood ketone testing is so awesome - why do hospitals still use the urine testing? We go to a great Children's Hospital in the DC area - and they still use the urine/not blood testing.