Intraosseous Transfusion

This may more aptly be called intraosseus infusion as the route is usually used for the infusion of fluids rather than for blood transfusion.

Bone marrow is a very vascular tissue and as such it can be a useful route to gain vascular access, usually in children. The technique of intraosseous infusion was first described in humans in 1934 and it became increasingly popular in the 1940s. The use of the intraosseus (IO) route is still regarded as somewhat controversial in many quarters. It has gained considerable acceptance over the past 20 years, especially in critically ill or injured children, often with trauma or burns.

It is usually reserved for children but can be employed at any age. The technique may appear to be strictly for the specialist but gaining intravenous access in children can be extremely difficult and require great skill. This technique has few contra-indications and the success rate is very high, even when performed by paramedical personnel, whilst the rate of complications is very low. It tends to be restricted for use in children in crisis such as cardiac arrest, shock, trauma, life threatening status epilepticus, or any situation in which the potential benefit of rapid venous access outweighs the low incidence of complications.¹

Saphenous vein cutdown has now almost completely disappeared in favour of the IO route in children. It remains available even in shock and is indicated in an emergency when other methods are unavailable or unsuitable. In the neonate it may be easier and quicker than umbilical vein catheterisation in an emergency. It has a very good outcome in neonatal resuscitation where other attempts at vascular access have failed.² Use for neonatal resuscitation is supported by international guidelines.³

Guidelines state that during CPR in children younger than 6 years, obtain intraosseus access if unable to achieve reliable venous access after three attempts or 90 seconds, whichever comes sooner. Intraosseus access has the same benefits in children over 6 years but access to the anterior tibial marrow is more difficult and other sites such as the lower femur, iliac crest or sternum should be considered.

• It can be considered in other situations too where there is circulatory collapse as in severe dehydration.⁴
• It also gives access for rapid delivery of fluids in children with burns.⁵
• It is possible to give all resuscitation fluids except bretylium.
• It is possible to achieve high flow rates especially if using a syringe to infuse fluid.
• It can be used to administer blood.⁶

Relative contraindications include fractured limb, local infection or osteomyelitis and severe bone disease, especially osteogenesis imperfecta.

• This description is based on that provided by Médecins sans Frontières and the reader if recommended their website as listed at the end.
• Ideally this should be a sterile procedure using a specific needle but it is possible to use a bone marrow aspiration needle or any 14 to 20 gauge needle with an internal stylus in an emergency. Even use of a butterfly needle is reported.⁴
• Palpate the tibial tuberosity. The site for cannulation lies 2 to 3cm below this tuberosity on the anteromedial surface of the tibia. An insertion site of at least 10 mm distal to the tibial tuberosity is recommended to avoid injury to the epiphyseal growth plate and to ensure ease of insertion.⁷
• Use sterile gloves with an aseptic technique and a sterile needle. Clean the skin. Placing a bone marrow needle without using a sterile technique increases the risk of osteomyelitis and cellulitis.
• Inject a small amount of local anaesthetic in the skin and continue to infiltrate down to the periosteum. This is unnecessary in an unconscious child.
• Flex the knee and put a firm support behind the knee.
• Hold the limb firmly above the site of insertion, usually at the level of the knee. Avoid putting your hand behind the site of insertion to avoid accidentally injuring your own hand.
• Insert the intraosseus needle perpendicular to the skin and slightly caudal (towards the foot) to avoid the epiphysial growth plate.
• Advance the needle using a drilling motion until a 'give' is felt. This occurs when the needle penetrates the cortex of the bone. Stop inserting further.
• Remove the trochar. Confirm correct position by aspirating blood using a 5ml syringe. If no blood can be aspirated the needle may be blocked with marrow. To unblock the needle, slowly syringe in 10 ml of saline.
• Check that the limb does not swell up and that there is no increase in resistance.
• If the tests are unsuccessful remove the needle and try the other leg.
• Connect to an infusion set with a short extension and three-way tap to reduce traction on the needle. Immobilize the access with a dressing and tension relief with adhesive tape between the leg and the infusion set.

Correct placement is further confirmed by:

• A sudden loss of resistance on entering the marrow cavity. This is less obvious in infants as they have soft bones.
• The needle remains upright without support. Because infants have softer bones, the needle will not stand as firmly upright as in older children.
• Fluid flows freely through the needle without swelling of the subcutaneous tissue.

Change to venous access as soon as adequate resuscitation is achieved.

Newer devices, such as the 'bone injection gun' (BIG), may increase the use of this route. It may be a little quicker to use⁸ and it may even be suitable for mass use in chemical warfare where there are many casualties needing vascular acccess and staff are encumbered by personal protective equipment (PPE) clothes.⁹

Complications from IO access are rare:

• Fractures and osteomyelitis after long-term use or when hypertonic solutions have been used.
• Fat embolism is less likely in children than in adults and has minimal clinical consequences.
• Local extravasation of fluids due to incomplete penetration of the needle into the cortex, IO infusion into a fractured limb, or perforation of the bone may lead to a compartment syndrome.¹⁰
• Follow up in neonates has excluded concerns about injury to growing bone and the growth plate.¹¹