INTRAOSSEOUS (IO) ACCESS IN CHILDREN
Intraosseous (IO) access is a lifesaving alternative when peripheral IV access fails, especially in critically ill or arresting pediatric patients. It provides rapid vascular access by delivering fluids and medications directly into the bone marrow, which acts as a non-collapsible venous network.
Why is IO Access Important?
- Fast and reliable alternative to IV in emergencies.
- Allows immediate fluid resuscitation and medication administration.
- Recommended by PALS/ACLS when IV access is difficult or delayed.
INDICATIONS FOR IO ACCESS
IO access is indicated when peripheral IV access is not quickly achievable, typically within 60-90 seconds in a critically ill child.
Common Indications:
Failure to obtain IV access after multiple attempts. Cardiac arrest or life-threatening shock. Severe dehydration requiring immediate fluid resuscitation. Status epilepticus requiring urgent IV medication. Sepsis, trauma, or burns where venous access is challenging.
Contraindications:
- Fracture or significant injury to the targeted bone.
- Previous IO attempt in the same bone.
- Infection or cellulitis over the insertion site.
- Osteogenesis imperfecta (brittle bone disease).
COMMON IO ACCESS SITES IN CHILDREN
The best IO site depends on the child’s age, anatomy, and clinical condition.
Site Best For Landmarks
Proximal Tibia (Most Common) All ages 1-2 cm below tibial tuberosity, medial to tibial shaft
Distal Femur Infants & small children Midline, 1-2 cm above patella, perpendicular to femur
Proximal Humerus (Preferred in older children/adolescents) Larger children & adolescents Greater tubercle, lateral to bicipital groove
Proximal Tibia is the first-line site in most children due to ease of access and large marrow cavity. Humeral Head is preferred in older children and adolescents as it allows faster systemic drug delivery due to proximity to the heart.
Avoid placing IO lines in fractured bones or sites with prior IO attempts (to prevent extravasation).
TECHNIQUE FOR IO INSERTION
Equipment Needed:
- IO needle (size varies by age).
- Manual or powered IO insertion device (e.g., EZ-IO drill, Cook needle).
- Syringe with normal saline flush (5-10 mL).
- Lidocaine (if patient is conscious) to reduce insertion pain.
Steps for IO Insertion:
Position and Prepare the Site
- Place the child in a supine position with the limb immobilized.
- Identify the correct landmark (e.g., proximal tibia 1-2 cm below the tibial tuberosity).
- Clean the site with antiseptic solution (chlorhexidine or iodine).
Insert the IO Needle
- Use an IO drill (EZ-IO) or manual IO needle.
- Insert at a 90-degree angle to the bone with firm, steady pressure.
- Stop when a sudden “pop” or decrease in resistance is felt (indicating entry into the marrow cavity).
Confirm Proper Placement Aspiration of bone marrow (not always present). Flush with 5-10 mL saline – should flow easily without resistance. No signs of swelling or extravasation at the site.
Secure the IO Line
- Attach an extension set and secure the needle with tape or a commercial stabilizer.
- Label the insertion time (IO lines should be removed within 24 hours to reduce infection risk).
If the flush does not flow freely, suspect malposition or extravasation and remove the IO.
COMPLICATIONS & TROUBLESHOOTING IO ACCESS
Common Complications:
Complication Cause Solution
Extravasation (Fluid Leakage) Misplaced IO or excessive movement Remove IO, apply pressure, and use another site
Infection (Osteomyelitis) Prolonged IO placement (>24 hours) Remove IO ASAP if signs of infection
Pain with Infusion No pain control in conscious patients Give lidocaine flush before fluids
Fracture Incorrect placement or excessive force Use an alternative site
If extravasation occurs, stop infusion immediately and monitor for compartment syndrome.
MEDICATIONS AND FLUIDS THROUGH IO ACCESS
Any IV medication or fluid can be given via IO access. The absorption rate is similar to a central venous line.
Fluids:
Normal saline, lactated Ringer’s, D5W Blood products (packed RBCs, plasma) Glucose (D10, D25, D50) for hypoglycemia
Medications:
Epinephrine (1:10,000) – 0.01 mg/kg IV/IO for cardiac arrest Atropine, adenosine, amiodarone (PALS drugs) Sodium bicarbonate (for metabolic acidosis) Antibiotics (if sepsis is suspected)
Give all medications with a 5-10 mL saline flush to ensure delivery into circulation.
COMPARISON: IV VS. IO ACCESS IN PEDIATRIC EMERGENCIES
Feature Peripheral IV Intraosseous (IO)
Speed of Placement Slower, especially in critically ill children Faster (within 30-60 seconds)
Reliability Can be difficult in shock/dehydration Reliable, non-collapsible venous access
Usability First-line in most cases Used only when IV access fails
Medications & Fluids Any IV-compatible drugs Same as IV, including blood products
Complications Infiltration, phlebitis Extravasation, osteomyelitis, fracture
IO access should be attempted immediately if IV attempts fail in critically ill children.
SUMMARY: WHY IO ACCESS IS A CRITICAL RESUSCITATION SKILL
IO access is the fastest and most reliable alternative when IV access is not available. Proximal tibia is the preferred site in most children; humeral head is ideal for older children. All emergency medications and fluids can be given IO. IO should be removed within 24 hours to prevent complications.
Takeaway: In life-threatening pediatric emergencies, IO access can be the difference between life and death. Mastering this technique ensures rapid intervention when time is critical.