Intravascular in the context of "Absorption (pharmacology)"

Intraosseous infusion (IO) is the process of injecting medication, fluids, or blood products directly into the bone marrow; this provides a non-collapsible entry point into the systemic venous system. The intraosseous infusion technique is used to provide fluids and medication when intravenous access is not available or not feasible. Intraosseous infusions allow for the administered medications and fluids to go directly into the vascular system. The IO route of fluid and medication administration is an alternative to the preferred intravascular route when the latter cannot be established promptly in emergency situations. Intraosseous infusions are used when people have compromised intravenous access and need immediate delivery of life-saving fluids and medications.