Paeds · investigations-procedures-and-technology
Intraosseous access
Also known as IO access · Intraosseous infusion · Bone marrow access · EZ-IO insertion · Proximal tibial IO needle
A fellowship approach to intraosseous access in children covering the indication (failed intravenous access within 60 to 90 seconds in shock, arrest or status epilepticus), why the marrow cavity is a non-collapsible vein, the proximal tibial landmark (flat anteromedial surface one to two centimetres below the tibial tuberosity), device and needle-set selection by weight (EZ-IO 15 mm pink for 3 to 39 kg, 25 mm blue for 40 kg and over, 45 mm yellow for the adolescent or oedematous child), the stepwise insertion technique, confirmation, drug and fluid administration at intravenous doses, the preservative-free lidocaine 0.5 milligram per kilogram dose for infusion pain in the conscious child, the complications of extravasation and compartment syndrome, removal within 24 hours, and the neonatal and pre-hospital scenarios.
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Target exams
Red flags
- A child in shock, cardiac arrest, or status epilepticus in whom intravenous access cannot be secured within 60 to 90 seconds — place an intraosseous needle now rather than repeating failed cannulation attempts
- A swollen, firm, or painful limb after intraosseous placement with the infusion still running — extravasation until proved otherwise; stop, remove, and choose another site to prevent compartment syndrome
- An intraosseous needle left in beyond 24 hours — infection (osteomyelitis, cellulitis, septic arthritis) rises sharply with dwell time
- A conscious child given an intraosseous fluid infusion without preservative-free lidocaine — the marrow and periosteum are innervated and the infusion is severely painful
- Inserting through overlying infection, a burn, a fractured bone, or a site used for an intraosseous needle in the last 24 to 48 hours — choose the other limb
- Inability to aspirate marrow being read as a failed line — aspiration often fails even with correct placement; an easy flush with no swelling confirms the line
Life stages
Care settings
Clinical exam formats
Board mappings
- General and Community Paediatrics
- Recognition and management of the acutely ill child
- Procedural skills — intraosseous access
- Emergency and resuscitation medicine
- Current 2026 PREP curriculum — Learning Objective 2.2.1: Recognise, prioritise and manage an acutely ill infant, child or young person including emergency vascular access
- Clinical Applications
- Medical Sciences
- Procedural skills
- Short Cases
- Structured oral — acutely ill or collapsing child
- 1.4 Safely and appropriately performs practical procedures and uses medical devices
- 4. Patient management
- 8. Patient safety
- Foundation of Practice (FOP)
- Applied Knowledge in Practice (AKP)
- Clinical — structured oral and communication in an emergency
- General Pediatrics Content Outline — Emergency Medicine; Procedural skills
- Universal Task 4: Management and Treatment
- Patient Care 1: procedural competency
- Systems-Based Practice
- Medical Expert
- Collaborator
- Pediatrics: Procedural skill — intraosseous access
Overview & Definition
Picture a two-year-old brought to the emergency department cold, grey, and unresponsive with fulminating septic shock. The registrar cannot find a vein. Every second spent hunting for a peripheral cannula is a second the brain and heart go without perfusion. Intraosseous access is the answer to exactly this moment: a needle driven through the hard outer cortex of a bone into the soft, blood-filled marrow cavity inside, so that fluids and drugs can be delivered straight into the circulation. [1] [3]
Intraosseous (IO) access means placing a rigid needle through the cortex into the medullary cavity of a long or flat bone. The marrow space is not a dead-end: it holds a dense network of thin-walled venous channels that drain through a central venous canal into the systemic circulation. Because the bone holds these channels open, they do not collapse when the child is in shock — and that is the whole reason IO works when peripheral veins do not. [9] [12]
The procedure is old — first described in the 1920s and a mainstay of military and paediatric resuscitation for decades — but it was the arrival of the battery-powered drill in the 2000s that made it fast and reliable enough for routine first-line use. Today the EZ-IO drill is the default device across Australian and New Zealand paediatric and retrieval services, and a fellowship candidate is expected to know not only how to place the line but when to stop trying for a vein and place one. [7] [10]
References12ShowHide
- [1]Thim T, Løfgren B, Grove EL Intraosseous catheter placement in children New England Journal of Medicine, 2011.PMID 21631349
- [2]Okubo M, Komukai S, Izawa J, et al Intraosseous vs Intravenous Access for Epinephrine in Pediatric Out-of-Hospital Cardiac Arrest JAMA Network Open, 2025.PMID 40560587
- [3]Pifko EL, Price A, Busch C, et al Observational review of paediatric intraosseous needle placement in the paediatric emergency department Journal of Paediatrics and Child Health, 2018.PMID 29125229
- [4]Scrivens A, Reynolds PR, Emery FE, et al Use of Intraosseous Needles in Neonates: A Systematic Review Neonatology, 2019.PMID 31658465
- [5]Ting A, Smith K, Wilson CL, et al Pre-hospital intraosseous use in children: Indications and success rate Emergency Medicine Australasia, 2022.PMID 34704359
- [6]Keller A, Boukai A, Feldman O, et al Comparison of three intraosseous access devices for resuscitation of term neonates: a randomised simulation study Archives of Disease in Childhood Fetal and Neonatal Edition, 2022.PMID 34340986
- [7]Shavit I, Hoffmann Y, Galbraith R, et al Comparison of two mechanical intraosseous infusion devices: a pilot, randomized crossover trial Resuscitation, 2009.PMID 19586701
- [8]Reades R, Studnek JR, Garrett JS, et al Comparison of first-attempt success between tibial and humeral intraosseous insertions during out-of-hospital cardiac arrest Prehospital Emergency Care, 2011.PMID 21275573
- [9]Neuhaus D Intraosseous infusion in elective and emergency pediatric anesthesia: when should we use it? Current Opinion in Anaesthesiology, 2014.PMID 24651308
- [10]Feldman O, Nasrallah N, Bitterman Y, et al Pediatric Intraosseous Access Performed by Emergency Department Nurses Using Semiautomatic Devices: A Randomized Crossover Simulation Study Pediatric Emergency Care, 2021.PMID 30256319
- [11]Hasan MY, Kissoon N, Khan TM, et al Intraosseous infusion and pulmonary fat embolism Pediatric Critical Care Medicine, 2001.PMID 12797872
- [12]Orlowski JP, Porembka DT, Gallagher JM, et al The bone marrow as a source of laboratory studies Annals of Emergency Medicine, 1989.PMID 2589704