The V-A Medical Center in Iowa City is making changes it hopes will prevent medical mistakes. The hospital will soon use a new scanner system to dispense drugs. Chief of staff Kevin Dellsperger says the changes come after a study of the entire V-A system found employees made thousands of mistakes that resulted in hundreds of deaths.Dellsperger says patients and medications will be issued bar codes.Dellsperger says a problem recently arose at the Iowa City facility when the T-V hospital drama “E-R” was on in a patient’s room — as V-A doctors and nurses worked on a patient who was having a heart attack and heard instructions for medication from the TV. Now hospital employees turn T-Vs off. V-A doctors also must type out their prescriptions on computers to avoid handwriting errors.