Diesel. Everytime. We have a different problem up here. I've just completed my basic paramedic training (now need to wait for clinical placement, which doesn't include paediatrics by the way). We were briefly shown how to IO access on a disembodied small limb, all very unrealistic. But the real crux is that our service will not purchase the kits to put on the vehicles. Because they are not used very often they are not considered cost effective. Price of a child's life anyone? In your case being so close to hospital I'd run everytime. Unfortunately up here north of the border there are some huge distances to cover in areas. IO in these situations may be invaluable.