Preferred Sites for Intraosseous Access, Injection, and Needle Insertion

Intraosseous (IO) access is a critical technique in emergency medicine, especially when vascular access is challenging. While the terms 'intraosseous access,' 'intraosseous injection,' and 'intraosseous needle insertion' are often used interchangeably, each has distinct purposes and preferred anatomical sites. This article explores the ideal sites for each IO procedure, explains the differences between them, and addresses why the sternum, though sometimes used, is not commonly listed as a primary IO site.

Intraosseous Access: Preferred Sites and Use

Definition: Intraosseous access refers to the establishment of a stable access route into the bone marrow for continuous infusion or repeated medication delivery, particularly in emergency or critical care settings.

Preferred Sites:

• Proximal Tibia: A primary site in both adults and children due to easy accessibility and thick bone cortex.
• Proximal Humerus: Often chosen for adults when upper extremity access is optimal.
• Distal Femur: Commonly used in infants and young children, particularly when other sites are not accessible.

Why These Sites? Proximity to major veins in the bone marrow allows for rapid systemic circulation, and these sites offer easier insertion with fewer complications.

Intraosseous Injection: Preferred Sites and Use

Definition: Intraosseous injection involves the direct administration of medication or fluids into the bone marrow cavity for rapid systemic absorption, typically used as a one-time, high-urgency measure.

Preferred Sites:

• Proximal Tibia: The go-to site for rapid access and efficient drug delivery, suitable for various patient ages.
• Proximal Humerus: Effective for adults, allowing for larger fluid volumes due to the proximity to the central circulation.
• Distal Femur: Selected for younger children when other sites are not easily accessible.

Why These Sites? Their dense marrow structure enables swift entry of medications into the bloodstream, crucial in time-sensitive situations.

Intraosseous Needle Insertion: Preferred Sites and Use

Definition: Intraosseous needle insertion refers to the act of placing a needle into the bone marrow cavity. It is the preparatory step for either establishing access or delivering an injection.

Preferred Sites:

• Proximal Tibia: Most commonly used across various age groups, providing a reliable insertion point.
• Proximal Humerus: Offers high success rates in adults, especially when limb positioning favors this site.
• Distal Femur: A preferred site in pediatrics due to accessible bone structure.

Why These Sites? These locations offer relatively thin cortical bone and are easy to locate by palpation, which increases accuracy and reduces the risk of complications.

Affordable IO Trainer to simulate practice on proximal tibia, and proximal humerus:

• Basic Intraosseous (IO) Injection Trainer
• Tibia IO Task Trainer with Removable Bone

Why Isn't the Sternum a Preferred Site?

While the sternum can be used for IO access, it is typically avoided due to its proximity to vital organs, like the heart and lungs. Inexperienced operators risk complications, such as accidental puncture. The sternum is occasionally used in specialized scenarios, such as military or extreme emergency settings, where traditional access points may be compromised (e.g., due to protective armor).

Portable Intraosseous (IO) Access Trainer to simulate IO needle insertion on sternum:

• Basic Intraosseous (IO) Access Trainer

Related Articles:

• IO Trainer: Mastering Intraosseous Access for Efficient Emergency Response