Intraosseous Access with EZ-IO: Technique and Complication Management
When the vein fails, the answer isn’t a fifth attempt at the skin — it’s a drill and the marrow cavity of the bone.
The second installment of the Micro-Interventions series covers intraosseous (IO) access using the EZ-IO drill system — a fast, reliable alternative to vascular access when a peripheral vein fails or takes too long to obtain.
Why to reach for IO access sooner than it seems necessary
Intraosseous access is a standard part of both ERC and AHA algorithms as an alternative whenever peripheral or central venous access is difficult or its acquisition unreasonably slows resuscitation. The marrow cavity of long bones is lined with a rich network of venous sinusoids that drain directly into the central circulation — a drug given via the IO route reaches the central circulation practically as fast as via peripheral IV.
Dispatched to a patient after a fall from a ladder with suspected massive retroperitoneal blood loss. BP 78/42, HR 128/min, skin pale, diaphoretic, peripheral veins collapsed and impalpable. After two failed peripheral IV attempts within 90 seconds, the crew proceeds to intraosseous access.
Decision: in a critically ill patient with no rapidly available vein, IO access is plan B — not a last resort after five wasted attempts at IV access.
Clinical indication
Urgent need for vascular access in a life-threatening condition (CPR, severe hypovolemic or distributive shock, status epilepticus, severe anaphylaxis) after peripheral IV access has failed — roughly after 2 failed attempts or approximately 90 seconds.
Contraindications and limitations
Fracture of the target bone, prior orthopedic procedure or prior IO attempt on the same bone within the last 24 hours, infection or burn at the insertion site, inability to identify landmarks. With multiple contraindications on one limb, consider an alternate site (contralateral tibia, proximal humerus).
Step-by-step procedure
Site choice also affects delivery speed — the proximal humerus generally allows higher flow rates than the proximal tibia due to its larger marrow volume, which can matter for massive fluid resuscitation. On the other hand, it’s harder to access in a shocked patient or when the upper limb is restricted, so the proximal tibia remains the most common first choice in the field.
Overview of insertion sites
| Site | Population | Note |
|---|---|---|
| Proximal tibia | adults and children | most studied, easy landmarks |
| Proximal humerus | adults | higher flow rates, less painful |
| Distal tibia | children over 6, adults | alternative site |
| Distal femur | young children | infants and toddlers |
Classic IO vs. peripheral IV access
In severe peripheral vasoconstriction, veins collapse and become practically inaccessible — exactly when access is needed most.
Venous sinusoids in the marrow do not collapse even in severe vasoconstriction. Speed of decision (after 2 attempts/90s) is key to resuscitation success.
Complications and their management
Complications are rare with correct technique but must be actively ruled out with every administration. The most serious include extravasation with risk of compartment syndrome, local infection or osteomyelitis with prolonged dwell time, fat embolism, and, with gross technical error, bone fracture. Risk is minimized by checking needle placement before every administration, monitoring the surrounding area throughout transport, and removing the IO line as soon as alternative access is available.
Common field mistakes
| Mistake | Consequence |
|---|---|
| Inserting without confirming the 5mm mark | incorrect depth |
| No flush before drug administration | “no flush = no flow” |
| Leaving the line in place beyond 24 hours | infection risk |
| Catheter movement during transport | dislodgement, extravasation |
| Missing swelling around the site after a bolus | unrecognized extravasation |
Documenting the procedure
“We drilled into his leg, worked fine.”
“After 2 failed peripheral IV attempts, IO access established with EZ-IO in the right proximal tibia. Confirmed by free-flowing 10 mL saline flush with no swelling around the site. Epinephrine administered via IO route per CPR protocol.”
“It came out, so we tried again.”
“Increasing swelling noted around the IO insertion site during transport — suspected extravasation. Administration stopped immediately, catheter removed, alternate peripheral IV access secured on the other limb.”
Practical takeaways for the responder
1. Consider IO access after 2 failed IV attempts or roughly 90 seconds.
2. Before administering any drug, always confirm placement with a saline flush bolus (10–20 mL).
3. Continuously check the insertion site throughout transport for extravasation.
4. Remove the IO line within 24 hours or as soon as alternative vascular access is obtained.
- REVERT Maneuver for Paroxysmal SVT
- Intraosseous Access with EZ-IO (this article)
- Celox Hemostatic Gauze for Junctional Hemorrhage
- Needle Decompression of Tension Pneumothorax
- Airway-Opening Maneuvers
- Nasopharyngeal Airway
- Applying the CAT Tourniquet
- Manual In-Line Cervical Spine Stabilization During Extrication
- Head and Cervical Spine Fixation on a Vacuum Mattress
- Peripheral IV Cannulation in the Centralized Patient
- Applying a Chest Seal for Open Pneumothorax
- Intraosseous access. Knowledge @ AMBOSS.
- Intraosseous Access — OSCE Guide. Geeky Medics.
- Intraosseous (IO) Device: What Is It, Risks and Benefits, and More. Osmosis.
- Petitpas F, et al. Intraosseous Access Technique. Medscape.