41: Venous Access: Intraosseous Infusion

Intraosseous (IO) infusion is used for emergency vascular access (fluids and medications) when other access methods have been attempted and cannot be quickly established or have failed. The umbilical vein is the preferred route in a hospital setting, but IO access can be considered if rapid intravenous access is essential and the operator is not experienced in umbilical vein catheter (UVC) placement.

Povidone-iodine solution, 4 × 4 sterile gauze pads, sterile towels, gloves, IO device (devices approved for newborns are available; Table 41–1), syringe with saline flush, IV fluid, and infusion setup.

1. Contraindications include bone diseases (eg, osteogenesis imperfecta, osteopetrosis), infection of the overlying skin, presence of a fracture, and thermal injury to the overlying skin. There is limited data but IO seems safe in preterm infants.

2. The proximal tibia (anteromedial surface) is the preferred site in the infant (vs the sternum in adults) and is described here (Figure 41–1). The intramedullary vessel in the tibial marrow empties into the popliteal vein and into the femoral vein. The other 2 most common sites used in newborns are the distal femur and distal tibia.

3. Select the area in the midline on the flat surface of the anterior tibia, 1–2 cm below the tibial tuberosity. Some recommend inserting a minimum of 10 mm (1 cm) distal to the tibial tuberosity: this avoids epiphyseal growth plate injury, and the thinner cortex here ensures an easier insertion.

4. Restrain the patient's lower leg and place a small sandbag or IV bag behind the knee for support.

5. Clean the area with povidone-iodine solution. Sterile drapes can be placed around the area.

6. Pain management. Lidocaine (0.5–1%) can be injected into the skin, soft tissue, and periosteum, but this is optional as this is usually an emergency procedure.

7. IO needle insertion. (See specific devices in Table 41–1.) Insertion site should be at least 10 mm distal to tibial tuberosity to avoid epiphyseal growth plate.

   1. Spinal, bone marrow biopsy, or intraosseous needle. Insert the needle at a 10- to 15-degree angle toward the foot to avoid the growth plate. Advance the needle until a lack of resistance is felt (usually no more than 1 cm is necessary), at which point entry into the marrow space should have occurred. Note: It is best not to place the other hand under the tibia for stabilization, as excessive force may cause the needle to pass through the bone and exit on the other side.

   2. B.I.G. Pediatric device. Dial the age to get the appropriate needle depth. Position device at 90 degrees to the skin and hold firmly with one hand while the other hand pulls out the safety latch. It uses a “position and press” mechanism with a spring-loaded device that penetrates the cortex when the button is pushed. No additional force is needed other than holding the device firmly against the skin. Manufacturer-recommended site for infants is 0.5 inches medial and distal to the tibial tuberosity.

   3. EZ-IO Pediatric. (Only recommended for infants >3 kg.) Device operates like a drill. It has a tip that rotates into the IO space at a preset depth. Once the needle enters the space, the stylet is withdrawn and a metal catheter remains with a Luer lock attachment. Manufacturer recommends removal within 24 hours.

8. Once the device is in place, remove the stylet and tape needle in place. Bone marrow aspiration for laboratory studies can be done, if needed. Bone marrow aspirates can be sent for chemistry, pH, Pco₂, hemoglobin, culture and sensitivity (C&S), blood type, and cross match. Even if marrow can't be aspirated, the IO needle can be used if it flushes without extravasation. If appropriate, secure the needle to the skin with tape to prevent it from dislodging.

9. Attach the needle to IV fluids and infuse at same rate used for IV route. Hypertonic and alkaline solutions should be diluted 1:2 with normal saline. Administer at the same rate as that for an IV infusion. Any fluid or medication that can be used via a peripheral IV can be used via the IO route (Table 41–2).

10. Confirm appropriate IO needle placement by aspiration of blood or bone marrow and also by the free gravity flow of crystalloid without extravasation. Ultrasound confirmation can be obtained, but a plain radiograph confirms position and is usually obtained to rule out fracture. Because of the risk of a fracture, a follow-up radiograph should be obtained in all infants in whom IO was attempted.

11. IO vascular access should optimally be used for <2 hours to minimize the risk of infectious complications, with some devices U.S. Food and Drug Administration (FDA) approved for longer use. When completed, withdraw the needle, apply pressure, and dress the site.

12. With unsuccessful IO placement do not repeat attempts at the same site or use the same site for 1–2 days.

1. Most common is extravasation. If giving caustic/vasoconstrictive medications, such as dopamine, and extravasation occurs, tissue damage is possible. Subperiosteal infiltration of fluid can also occur.

2. Infections. Localized cellulitis, subcutaneous abscess, periostitis, and sepsis have all been reported. Osteomyelitis is rare (<0.6%). To prevent osteomyelitis, hypertonic and alkaline solutions and all medications should be diluted. Sterile technique is important and if compromised consider antibiotic coverage.

3. Clotting of bone marrow. Results in loss of vascular access.

4. Iatrogenic bone fracture. Radiograph confirmation of the needle should be done to confirm position and rule out fracture (tibial fracture is most common).

5. Compartment syndrome. Due to prolonged infusion and extravasation. The leaking fluid collects in the spaces between the muscles of the leg.

6. Blasts in the peripheral blood. These have been noted after IO infusions.

7. Fat embolism. Much less likely in infants than adults. Before the age of 5 years, the intramedullary space consists mainly of red marrow, which is more vascular and has a lower fat component.

8. Bone growth concerns have been ruled out. Studies have shown there is no long-term effect on tibial growth after IO infusion with a properly placed IO needle trocar. At the tibia, IO blood transfusions may result in transient radiologic changes but do not impact bone growth.

9. Needle dislodgement.