In part one of this series we talked about the indications, contraindications, MRI conditional compatibility and what medications can be administered via an intraosseous route. Today we will further unpack the specific needle sizes, driver options, usage and potential anatomic sites for insertion using the EZ-IO system. As stated earlier, intraosseous access should be reserved and utilized in not only the critical patient that has difficult vascular access (DVA), but also any patient with DVA that is urgent, emergent or medically necessary and requires rapid, reliable shorter term vascular access. Think of the EZ-IO system as a bridge device between no rapid, reliable vascular access and a longer term indwelling device.
While intraosseous access can occur in a variety of bone structures, the EZ_IO system utilizes the proximal and/or distal ends of the human long bones. This anatomical location lends itself to easier landmarking and overall better performance as it pertains to medication administration. There are 6 potential insertion sites on the adult patient that include the proximal and distal tibia bilaterally and the proximal humerus bilaterally. The distal and/or proximal ends of the long bones provide a larger anatomical target for landmarking. The majority of the red bone marrow, which contains millions of red blood cells is concentrated at the ends of the long bones. Yellow bone marrow is much more prevalent in the mid shaft of the long bones. Finally, the cortical bone or the hard part of the bone structure itself is at its thinnest at the ends of the bones and is only about 3-5 mm in thickness. As we get closer to the mid shaft of the long bones, the cortical bone gets thicker and the inter medullary space gets smaller.
All currently available EZ-IO needles are 15 gauge #304 stainless steel and come in 3 lengths to accommodate a variety of tissue thicknesses. The pink needle is 15 mm in length and is utilized for patients from 3-39 kg, The blue needle is 25 mm in length and is indicated for patients above 3 kg with no maximum weight restriction and the yellow 45 mm needle is indicated for all patients weighing more than 40 kgs or with an excessive tissue depth overlying the insertion site. All needles have a removable stylet that will aid in insertion and can be removed prior to infusion. Each needle also has black lines on the needle that assist with assessing overlying tissue depth as well as insertion depth. While all needles are designed to be utilized with the EZ-IO driver system, they can all be inserted manually in the event of a driver failure.
The EZ-IO driver now comes in a reusable form and a single use disposable form. The multi-use driver is non-rechargeable and the batteries are not replaceable however the manufacturer states it has a 10 year shelf life and can be used for up to 500 insertions depending on storage and usage. The battery indicator for the multi use driver will flash green during insertion when the battery is good and will flash red when the battery life expectancy is less than 10%. The single use disposable driver comes in a pack with an EZ-IO needle, a site preparation cleaning swab, an IO extension set, IO needle stabilizer, single use sharps container and instructions for use on the inner portion of the package wrap. A fluorescent pink EZ-IO wristband that includes a spot to document the insertion time and date as well as the internet address for the device’s manufacturer and a toll free phone number to utilize in the event of a question or issue as it pertains to the EZ-IO system is also included.
As you can see, IO access has come a long way over the past 3-4 decades and will more than likely continue to improve not only in design but also in reliability, functionality and options for use. While not meant to replace peripheral intravenous access, the EZ-IO system offers the provider yet another “tool in the tool box” as far as improving patient care and decreasing downstream morbidity and mortality. Stay tuned for part 3 of this series where we will talk about landmarking and needle size selection.
