In which situation should intraosseous (IO) access NOT be placed?

Intraosseous (IO) access is a critical route for medication and fluid administration when intravenous access is challenging or impossible. However, certain conditions can complicate or contraindicate its use.

When there is a tourniquet applied to an extremity, the resultant ischemia can severely limit blood flow to the bone and surrounding tissue. This lack of blood flow may lead to complications such as necrosis or infection and can also affect the efficacy of drug delivery through the IO route. The drugs administered could be less effective or not reach systemic circulation due to the compromised blood flow, undermining the purpose of establishing IO access in the first place.

In contrast, scenarios such as shock, potential fractures, or severe hypothermia do not inherently preclude the use of IO access; precautions can be taken to manage those situations appropriately. In severe hypothermia, the concern would more broadly relate to overall patient care rather than imminent IO access. Thus, the presence of a tourniquet represents a specific contraindication due to the effects it has on the circulation in the chosen limb.