IO access is preferred when vascular access is needed but two IV attempts have failed and/or access is not quickly obtainable via the IV route. Starting an IV on someone in shock, with diminished perfusion of the extremities, may be very challenging, and IO techniques do not rely on expanded veins for successful placement. Intraosseous access has a higher success rate when compared to IV access in limited visibility environments.

As with IV access, not all IO access requires that fluids be continuously administered.

Currently, there isn’t a list of IO devices that are specifically recommended by the Committee on Tactical Combat Casualty Care (CoTCCC). However, there are a few that seem to be more commonly used in TCCC settings, to include the FAST1® Intraosseous Infusion System and the EZ-IO® system. The FAST1 is used at a sternal insertion site, while the EZ-IO can be used at a sternal, a humeral, or a tibial insertion site. Each system has its own guidance on insertion methods and procedures; it is imperative that you spend time training on the device (or devices) that you are likely to deploy with.

Osteoporosis is a medical condition in which the bones become brittle/fragile due to loss of tissue, a result of hormonal changes or a deficiency of vitamin D or calcium.

Osteogenesis imperfecta is a disorder characterized by severe fragility of the bones (known as brittle bone disease).

The FAST1 system should be avoided in casualties of small stature (less than 50 kg) who have had significant chest trauma (in particular a flail chest) or if there is a scar indicating a prior sternotomy.