Whether due to trauma or disease, vascular collapse may delay or preclude even experienced medical providers from obtaining standard intravenous (IV) access. Access to the vascular system of the critically ill or injured adult or pediatric patient is essential for resuscitation, and flow rates close up to what can be obtained by using intravenous access is preferable in patient needing immediate fluid boluses for shock resuscitation. Intraosseous access takes advantage of the vascularity of cancellous bone, the spongy bone inside the hard, and access to the highly vascular intramedullary space of bones provides a direct link to central circulation. In addition to using long bones, the sternum is used for intraosseous access and has gained increased use especially in combat casualty care.