Equipment Povidone-iodine or chlorhexidine antiseptic solution; sterile gauze; gloves; drapes; 1% lidocaine; 3- to 5-mL syringe; 18- or 20-gauge intraosseous infusion needle; or commercially available IO device (EZ-IO [Arrow/Teleflex] or bone injection gun [Waismed/PerSys Medical]); saline flush solution; IV fluids and tubing Alternatives: bone marrow aspiration needle; 20-gauge lumbar puncture (LP) spinal needle Procedure Preferred locations are the proximal tibia or distal femur for ease of access and safety Prepare the selected site by cleansing with antiseptic solution In the awake patient, infiltrate from the skin to the periosteum with 1% lidocaine for anesthesia The desired site for placement in the proximal tibia is the flat, medial surface to cm below the tibial tuberosity ( Fig 130.9A ) Alternatively, the lower third of the femur in the midline approximately cm above the lateral condyle ( Fig 130.9B ) or the distal tibia to cm proximal to the medial malleolus ( Fig 130.9C ) can be used In the absence of an intraosseous needle, a bone marrow sampling needle or a spinal needle with bevel can be used After penetrating the skin with the needle, direct it at a slight angle 10 to 15 degrees from vertical and away from the growth plate of the long bone (caudad for proximal tibia insertion; cephalad for distal femur insertion) Apply downward pressure with a “to-and-fro” rotary motion to advance the needle When the needle passes through the cortex of the bone into the marrow cavity, resistance will suddenly decrease (a “trap door effect”) The needle should stand firmly without support Remove the stylet and connect a 5-mL syringe to the needle Attempt to aspirate marrow to confirm placement of the needle tip in the marrow space If marrow cannot be aspirated, gently attempt to flush with saline and assess for signs of infiltration If the line can be flushed easily without signs of infiltration, placement is good Flush the needle with heparinized saline and connect it to conventional IV infusion tubing Observe the site for extravasation of fluid, which is an indication that either the placement is too superficial or the bone has been pierced through both sides Restrain the leg and maintain a clean infusion site while the needle is in place Use of the EZ-IO for placement involves the same preparatory steps to sterilize the site Use the 15-gauge, 15-mm needle for patients under 39 kg and the 15gauge, 25-mm needle for those over 39 kg There is also a 15-gauge, 45-mm needle available for use when excessive soft tissue overlies the desired insertion site Load the needle onto the magnetic tip of the drill Insert the needle through