Often in emergencies and other medical situations, doctors must gain vascular access (access to the blood stream) in order to give drugs and/or fluids to patients. The most common way to gain vascular access is to place a needle into a vein through the skin, but sometimes this is not possible. Another way to gain vascular access is to insert a needle through the skin, into the bone and give drugs and/or fluids to patients through the center of the bone, which is hollow and contains blood vessels. This is called intraosseous (IO) vascular access. One device used to gain intraosseous vascular access is called the EZ-IO® Intraosseous Vascular Access System and it can be used in the proximal humerus (upper arm bone), proximal tibia (upper shin bone), and the distal tibia (lower shin bone). The EZ-IO has been cleared by the FDA to establish IO vascular access in the sites identified above for the infusion of drugs and fluids anytime vascular access is difficult to obtain in emergent, urgent, or medically necessary cases.