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With availability and improved training on central venous lines and ultrasound-guided catheter placement, venous cut-downs for venous access are becoming almost unheard of in the acute care setting. The new IO systems will only make this less frequent. Cut-downs are still used to some extent for arterial access for invasive pressure monitoring in the ICU setting. As Crip said, this is absolutely a last resort, particularly because of the amount of time it takes, technical skill required, and lack of frequent practice.

Of the IO systems available (Jamshidi-type needle, EasyIO drill, Bone Injection Gun, and Fast1 sternal IO), I've used all on cadavers and all but the BIG clinically. Overall, the new systems are far and away better than the old "drive it in by hand" method, but have some limitations.

The FAST1 sternal is a decent system, but we've had some problems with placement and continued function. It requires pretty substantial pressure to place it. And there's that whole removal issue, where you have to bring the special t-bar to unscrew it from the sternum. The upside is that it is quick and ready to use right out of the package. It rattles a bit when carried, which is a potential drawback for noise discipline.

The Easy IO is just that- easy to use. It allows a bit more finesse with use, and utilizes the proximal tibia insertion site that we are all familiar with when taught IOs with the Jamshidi (though it can also be placed in the humerus or distal tibia). The drilling action means that very little pressure is applied, so there is less chance of breaking the bone or going through the opposite side of the cortex than with hand-driven needles. Of the systems out there, it is the heaviest and bulkiest when you take into account the driver unit. Previous issues with battery failure have been solved with the newer model having a lithium battery with 15 year shelf life for ~700 insertions. It comes with a small plastic handle that can drive the needle manually if there is a motor failure or if you don't want to carry the full driver, but then you could just as easily carry a Jamshidi. There is some research going on right now to develop a driver unit more compact for special operations use.

The Bone Injection Gun is the smallest and lightest of the 3 new units available, and consists of a spring-loaded mechanism to snap a needle into the proximal or distal tibia or distal ulna. We had some placement issues with this unit in a local fire/EMS system. What was found was that people were a) rocking the unit slightly off the insertion site, so it wasn't going in perpendicular, and b) inserting just off from where it's designed to be used. The BIG, when inserted in the proximal tibia, shouldn't go into the cortex at the site we are normally taught for IO (2 fingers down and one medial from the tibial tuberosity) because the bone is too thick. It needs to be inserted about one finger width medial and one proximal from the tibial tuberosity. Also, the way it is shown being held in the pictures, it looks like it needs substantial pressure. It actually doesn't, and can be held against the bone with 2 fingers and tapped with another finger to trigger insertion. Once these issues were addressed in training, they have worked very well.

As Swatsurgeon said, any IO needs to be on a pressure bag to run properly. There is substantial pain with infusion, as there are pressure-sensitive receptors in the cortex of the bone, which is often described as the worst part of the IO. A few ccs of lidocaine should go in before fluid is run to make the patient more comfortable. The systems all offer very rapid access, and I've been training our medics here to just go for the IO if they don't see a good IV site immediately available.


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