Florida State Paramedic Practice Exam

Where is the proper location for intraosseous (IO) placement?

1. Distal radius

2. Proximal tibia

3. Fifth metatarsal

4. Femur

The correct answer is: Proximal tibia

The proximal tibia is the proper location for intraosseous (IO) placement because it provides a reliable access point to the bone marrow's vascular system, which is crucial for delivering medications rapidly in emergency situations. The proximal tibia is situated just below the knee joint and is easily accessible through the skin, even in patients with difficult venous access. This site is favored in pediatric patients due to the anatomical characteristics of the bone in children, as well as its depth and proximity to major circulatory systems. When considering the other potential sites, the distal radius, while also a viable option for IO access, is not as commonly used as the proximal tibia because of its smaller medullary cavity and deeper location in some patients, making it more challenging for effective placement. The fifth metatarsal is typically not considered a primary site for IO insertion due to its smaller size and increased risk of injury and difficulty in securing the IO catheter properly. The femur can be used as an alternative site but is less frequently selected because of the greater skill required for insertion and the risk of complications, such as damage to surrounding structures. Thus, the proximal tibia remains the preferred and most accessible anatomical location for intraosseous needle insertion in emergency medical situations.