I used to watch Casualty until I did my nurse training and worked in a real A&E! If any FY1 or FY 2 medic suggested insulin to treat hypoglycaemia they would not be allowed to finish the shift, even if the consultant didn't stop the medic the nurse in charge certainly would do; patient safety comes first. All hospitals have a set procedure for dealing with a hypo. With regards to cardiac arrests as portrayed on Casualty, their success rate is far too high.