Intraosseous access is a medical procedure used to deliver fluids, medications, and blood products directly into the bone marrow. The term “intraosseous” literally means “within the bone.” This method provides a rapid and reliable way to administer life-saving treatments when traditional intravenous (IV) access is difficult or impossible to obtain.
Understanding Intraosseous Access
The effectiveness of intraosseous access stems from the unique characteristics of bone marrow. Bone marrow is highly vascular, rich in a network of blood vessels that drain directly into the central venous system. This extensive vascular network acts like a non-collapsible vein, allowing for rapid absorption of administered substances into the bloodstream. Even when a patient’s peripheral veins might collapse due to shock or low blood pressure, the intraosseous space remains patent, providing a consistent route for fluid and drug delivery.
Medical professionals use specific bones for intraosseous access due to their accessibility and substantial marrow cavity. In adults, common insertion sites include the proximal tibia (shin bone), the humeral head (upper arm bone), and sometimes the sternum (breastbone). For children, the distal tibia, proximal tibia, and distal femur are frequently chosen sites. Site selection depends on factors like the patient’s age, body habitus, and the urgency of the situation.
When Intraosseous Access Is Used
Intraosseous access is primarily an emergency intervention, reserved for urgent situations when immediate vascular access is essential for patient care. It becomes important when establishing traditional intravenous access is challenging or time-consuming. This can occur in scenarios such as severe trauma, where veins may be damaged or collapsed, or during cardiac arrest, when blood circulation is compromised.
Other situations requiring rapid intervention include states of severe shock, severe dehydration, or burns, especially in pediatric patients where peripheral IV access can be exceptionally difficult. Intraosseous access provides a swift and effective alternative, allowing medical personnel to deliver life-saving treatments promptly.
How Intraosseous Access Is Performed
Establishing intraosseous access involves inserting a specialized needle into the medullary space of a bone. This is achieved using a manual device or a powered drill-like tool. The needle is advanced through the outer layer of the bone, known as the cortex, into the marrow cavity.
These sites are chosen for their anatomical landmarks, which help trained medical professionals, such as paramedics and emergency physicians, accurately place the needle. The procedure is rapid, often taking only seconds, ensuring timely delivery of essential fluids and medications in emergency settings.
Safety and Patient Considerations
While intraosseous insertion can cause discomfort during the procedure, any pain is managed effectively once the line is established. This involves administering local anesthetic or pain medication to the conscious patient. Medical professionals are highly trained to perform this procedure, minimizing potential risks.
Though rare, potential complications can include infection at the insertion site, a hairline fracture of the bone, or extravasation, where fluid leaks outside the bone marrow cavity. The benefits of quickly securing a route for life-saving treatments in emergency situations far outweigh these potential risks. The intraosseous needle is removed as soon as alternative vascular access, such as a traditional intravenous line, can be successfully established, within 24 hours.