Intraosseous Access: Insertion Sites, Technique and Complications in Children and Adults

The role of intraosseous access

Intraosseous access (IO access) uses the non-collapsible venous plexus of the bone marrow. Through it, drugs and infusions reach the systemic circulation, even during centralisation, shock or cardiac arrest. In many emergency medical services and emergency departments, it is now part of the standard repertoire.

For adults in cardiac arrest, the ERC Guidelines 2025 (Adult Advanced Life Support) recommend attempting IV access first. IO access is intended for situations in which IV access is unsuccessful or not feasible. This recommendation is based on randomised trials in which primary IO access showed no survival benefit compared with IV access.

In paediatric emergency medicine, intraosseous infusion plays a more prominent role. According to the ERC Guidelines 2025 (Paediatric Life Support), it is an equivalent option when venous access cannot be established promptly. This applies particularly to infants and young children with difficult venous access.

Indications and contraindications

Typical indications

• Cardiac arrest without rapidly available IV access
• Severe shock (hypovolaemic, septic, anaphylactic) after unsuccessful venepuncture attempts
• Status epilepticus, severe burns or polytrauma when peripheral access cannot be obtained
• Time-critical drug administration with no venous alternative

Contraindications at the intended insertion site

• Fracture of the target bone or vascular injury proximal to it
• Previous IO insertion or unsuccessful attempt in the same bone
• Infection or burn of the skin over the insertion site
• Joint prosthesis or osteosynthesis material in the target area
• Landmarks that cannot be reliably palpated, for example in severe obesity

Relative contraindications include bone disorders with an increased tendency to fracture, such as osteogenesis imperfecta or severe osteoporosis. A careful risk–benefit assessment is required in these cases.

IO access: choosing the insertion site by age

The choice of IO insertion site depends on age, soft-tissue thickness, injury pattern and accessibility during ongoing interventions. Growth plates should always be avoided in children.

Adults

• Proximal humerus: Insertion at the greater tubercle. The arm is adducted and internally rotated, with the hand resting on the abdomen. The site remains easily accessible during chest compressions and allows high flow rates. However, the needle dislodges more easily with arm movement.
• Proximal tibia: Insertion on the flat anteromedial surface, distal and medial to the tibial tuberosity. Landmarks are easy to palpate, and the site is widely used and easy to train.
• Distal tibia: Insertion on the medial surface proximal to the medial malleolus. It is a suitable alternative in the presence of knee injuries.
• Sternum: Possible only with devices specifically approved for this site. During resuscitation, its use is limited by chest compressions.

Children

• Proximal tibia: Standard site in all age groups. Insertion is anteromedial, below the tibial tuberosity, at a sufficient distance from the growth plate.
• Distal femur: An alternative, particularly in infants and young children. Insertion is anterolateral, above the patella and the epiphyseal plate.
• Distal tibia: Suitable in older children, proximal to the medial malleolus.
• Proximal humerus: Only in older children with reliably palpable landmarks.

Exact anatomical distances and age-specific recommendations should be taken from the manufacturer's instructions for the device used and from local protocols.

Device choice

• Battery-powered drill systems: These are widely used and have high first-pass success rates. Needle length is chosen according to the soft-tissue thickness over the bone, not on body weight alone. Before drilling, a marking on the needle should still be visible after the soft tissue has been penetrated. This ensures that the length is sufficient to reach the cortex.
• Spring-loaded impact devices: These are compact and designed for defined insertion sites and age groups. Perpendicular placement with firm counter-pressure is important.
• Manual needles with stylet: These are particularly suitable for neonates and infants with soft bone. The needle is advanced with a rotating motion until resistance suddenly decreases ("loss of resistance").

The specific device matters less than regular training on exactly the device stocked in one's own area of practice.

Technique in brief

1. Identify the insertion site and position the limb securely. In children, do not place your hand behind the insertion site, to avoid self-injury if the needle passes through.
2. Disinfect the skin and work aseptically.
3. Place the needle perpendicular to the bone surface, or insert it angled slightly away from the growth plate.
4. Penetrate the cortex until a distinct loss of resistance is felt.
5. Remove the stylet, attach the extension set, pre-filled with saline.
6. Confirm position (see below), secure the needle and document the time of insertion.

Confirming position

No single sign reliably proves correct placement. Assessment is based on a combination of several findings:

• The needle stands firmly in the bone without support.
• Bone marrow can be aspirated. This is not always successful, so failure to aspirate does not exclude correct placement.
• A flush bolus can be given with little resistance and without swelling.
• Limb circumference and tension remain unchanged during infusion. The insertion site and the posterior aspect of the limb should be inspected repeatedly.

Aspirated bone marrow can be used for selected laboratory parameters, such as blood grouping or an approximate blood gas analysis. Values are only partly comparable with venous samples, and the evidence is limited. The laboratory or point-of-care device operator should be informed of the sample source, as bone marrow can block analysers.

Drugs and infusion

Drugs are given IO at the same dose as IV. An example from the ERC Guidelines 2025 is amiodarone for VF/pVT:

• Adults receive 300 mg IV/IO after the 3rd shock and 150 mg after the 5th shock.
• Children receive 5 mg/kg IV/IO (max. 300 mg) after the 3rd shock.

A flush is required after every drug administration. Gravity infusion via the IO route is often slow. For significant volume administration, a pressure bag is therefore used, or, in children, fractionated syringe boluses. Dwell time should be limited according to the manufacturer's instructions. As soon as reliable venous access is established, the IO access should be removed.

Practical tip: pain during infusion in the conscious patient

Many patients describe the insertion itself as relatively painless. Pressurised infusion into the medullary cavity, by contrast, is often considerably painful. The following points have proven useful in practice:

• Intraosseous local anaesthesia: Before the first flush bolus, preservative-free lidocaine is administered slowly IO. It should be allowed time to take effect before flushing and infusing. Depending on the product, this use may be off-label. Dose and procedure should follow the summary of product characteristics, the IO device manufacturer's instructions and the local protocol. In children, the dose must be calculated by body weight and assessed cumulatively with any other lidocaine administration.
• Systemic analgesia: If analgesia is indicated anyway, for example in trauma, it can be given early via the IO access. Dosing according to current guidelines and the summary of product characteristics.
• Slow initial flush: A slow initial flush bolus reduces pressure-related pain.
• Communication: Conscious patients or parents should be prepared for infusion pain.

Evidence on the optimal dose and onset time of intraosseous local anaesthesia is limited.

Complications

Complications are rare overall but can be serious. They depend heavily on correct placement and monitoring.

• Extravasation and compartment syndrome: The most significant acute complication, caused by malposition, penetration of the opposite cortex or dislodgement. Hyperosmolar or tissue-toxic substances and catecholamines are particularly hazardous.
• Dislodgement: Common during repositioning and transport, and at the humerus particularly with arm movement.
• Misplacement: Penetration through both cortices, especially in children with thin bone.
• Infection: Osteomyelitis or soft-tissue infection. The risk increases with dwell time, so work aseptically and remove early.
• Fractures: Predominantly in infants and in fragile bone.
• Growth plate injury: Considered rare when the insertion site is correctly chosen.
• Fat embolism: Theoretically possible, rarely clinically relevant.

For handover, the insertion site, time, substances administered and any abnormal findings in the limb should be documented. After removal, the insertion site is covered with a sterile dressing and the limb is monitored further.

Key points for practice

• In adults in cardiac arrest, ERC 2025 recommends attempting IV access first; IO access is the established alternative.
• In children, intraosseous infusion is an equivalent option when venous access cannot be obtained promptly.
• The insertion site depends on age and situation; growth plates should be avoided.
• Position is confirmed using several signs, and the limb must be monitored continuously.
• In conscious patients, infusion pain should be actively considered. Doses of IO local anaesthesia should follow the summary of product characteristics and local protocol.

References

• Soar J, Böttiger BW et al. European Resuscitation Council Guidelines 2025 Adult Advanced Life Support. Resuscitation 2025;215 Suppl 1:110769 (Korrigendum 2026).
• Djakow J, Turner NM, Skellett S et al. European Resuscitation Council Guidelines 2025 Paediatric Life Support. Resuscitation 2025;215 Suppl 1:110767.

This article does not replace clinical judgement in the individual case or the current summary of product characteristics and guidelines.