Interosseous vascular access 골수 주사,

IO VASCULAR ACCESS

The long bones of the body are richly vascular structures whose marrow cavities provide ready access to the venous circulation. The arterial supply to the bones is provided by a nutrient artery that penetrates the cortex and bifurcates into ascending and descending branches. These branches further divide into arterioles that penetrate the endosteal surface to become capillaries. The capillaries drain into medullary venous sinusoids within the medullary space, which drain into a central venous channel. Catheters placed in the venous sinusoids provide venous access.

IO vascular access is indicated in patients of all ages when venous access cannot be quickly and reliably established during circulatory collapse. The 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care recommend IO access over endotracheal drug administration during resuscitation.

Commercially available rapid IO drill devices, such as the EZ-IO^簧 (Vidacare Corp., San Antonio, TX), may be used (Figure 33-18). Contraindications to IO access include proximal ipsilateral fracture, ipsilateral vascular injury, and severe osteoporosis or osteogenesis imperfecta.

Technique for IO Access

The technique for IO access may be viewed; see videos: Intraosseous Infusion and Intraosseous Line Placement.

Use either a standard bone marrow aspiration needle or specialized IO infusion needle. In children, the site of entry is 2 finger-widths (2 cm) below the tibial tuberosity on the medial, flat surface of the proximal tibia (Figure 33-19). Use other sites, such as the medial malleolus, distal femur, sternum, humerus, and ileum, in adults, as the tibia is thick and difficult to penetrate.

The procedure for manual insertion of IO venous needles is summarized in Table 33-10 and illustrated in Figure 33-20. Physicians should familiarize themselves with the operating instructions of the rapid IO drill devices used in their EDs.

Complications

Complications of IO access include cellulitis, osteomyelitis, iatrogenic fracture or physeal plate injury, and fat embolism (rare).