Overview
Definition:
Intraosseous (IO) access is a method of obtaining vascular access by inserting a needle or catheter directly into the marrow cavity of a bone
It provides rapid and reliable access to the systemic circulation, particularly useful in emergency situations when peripheral intravenous access is difficult or impossible to establish.
Epidemiology:
IO access is indicated in approximately 10-15% of pediatric emergencies
Its use has increased significantly with improved devices and training
It is a crucial skill for all pediatric emergency physicians and intensivists.
Clinical Significance:
In critically ill or injured children, establishing vascular access quickly is paramount for resuscitation
IO access offers a vital alternative when traditional IV lines cannot be placed, enabling timely administration of fluids, blood products, and medications, thereby improving patient outcomes and survival rates.
Indications And Contraindications
Indications:
Cardiac arrest
Shock (hypovolemic, septic, cardiogenic)
Status epilepticus
Severe dehydration
Trauma
Burns
Difficult venous access due to obesity, edema, or shock
Any situation requiring immediate vascular access.
Contraindications:
Fracture at the insertion site
Osteogenesis imperfecta
Osteoporosis
Previous IO insertion in the same bone within 24-48 hours
Infection over the insertion site
Significant vascular compromise distal to the site
In neonates: particularly careful consideration is needed due to the thin cortex and potential for physeal injury.
Sites Of Intraosseous Access
Primary Sites:
Proximal humerus (medial aspect, 1-2 cm distal to the acromion)
Proximal tibia (medial aspect, 1-2 cm distal to the tibial tuberosity)
Distal tibia (medial malleolus, 1-2 cm superior to the malleolus)
Distal femur (anterior or medial aspect, 2-3 cm proximal to the medial condyle).
Secondary Sites:
Iliac crest (posterior superior iliac spine)
Sternum (rarely used in pediatrics due to risk of great vessel injury)
Calcaneus (used in infants and neonates).
Site Selection Criteria:
Easily identifiable landmark
Adequate bone thickness
Minimal risk of neurovascular injury
Proximity to the desired infusion site
Avoidance of previous insertion sites or fracture sites.
Procedure And Devices
Insertion Technique:
Identify the landmark
Prepare the skin with antiseptic solution
Use a sterile technique
Insert the needle at a 90-degree angle (or 60-75 degrees for proximal humerus) into the bone cortex, aiming towards the medullary cavity
Advance until a "give" is felt, indicating entry into the marrow
Aspirate bone marrow to confirm placement
Secure the needle/catheter with a sterile dressing.
Types Of Devices:
Manual needles (e.g., Jamshidi needle)
Automatic bone marrow needles (e.g., EZ-IO, Bone Injection Gun (BIG))
These devices offer faster insertion and are often preferred in emergency settings.
Confirmation Of Placement:
Aspiration of bone marrow
Inability to aspirate air
Stable infusion without signs of extravasation
Free flow of fluid upon flushing
Absence of a "to and fro" pulsatile flow against the syringe.
Complications Of Intraosseous Access
Early Complications:
Extravasation of infusate (most common complication, leading to swelling, pain, and potential compartment syndrome)
Pain (can be severe, requiring analgesia)
Subcutaneous or soft tissue infiltration
Bone fracture (rare with proper technique)
Failure to cannulate.
Late Complications:
Infection (osteomyelitis, cellulitis, septic arthritis, particularly if strict asepsis is not maintained)
Physeal (growth plate) injury (more common in younger children with repeated or improper insertions)
Thrombophlebitis
Fat embolism (rare).
Prevention And Management:
Strict adherence to sterile technique
Proper landmark identification
Correct needle angle and depth
Use of appropriate size device
Frequent monitoring of the insertion site for swelling or leakage
Adequate analgesia
Prompt removal of IO device once peripheral IV access is established
Prompt treatment of any signs of infection.
Key Points
Exam Focus:
IO access is a critical life-saving skill in pediatric emergencies
Understanding the primary insertion sites and potential complications is essential for DNB and NEET SS exams
Differentiate between early and late complications.
Clinical Pearls:
Always confirm IO placement before infusing large volumes
Pain management is crucial
consider intraosseous lidocaine if awake
Remove the IO catheter as soon as reliable IV access is obtained to minimize complication risk
The tibia and humerus are the most common and easiest sites.
Common Mistakes:
Incorrect landmark identification leading to failed insertion or neurovascular injury
Failure to maintain sterile technique
Over-insertion of the needle
Not confirming placement properly before infusion
Delaying removal of the IO device.