Obtaining “access” in remote or austere environments is something that can be very difficult and honestly something I worry about often. The ability to give fluid, medications or blood can literally make the difference betwen life or death. Working remotely, I try to have at least TWO methods if I cannot access peripheral veins via a cannula.
In order of personal preference I use:
- Intraosseous
- Central line
- Venous Cutdown
Lets take a look at the first of these in this Part one post:
1) Intraosseous
There are many commercial kits available to insert a needle into bone. Personally, I trained with the older style “cork-screw” models that were primarily reserved for pediatric patients. Currently, the Intraosseous (IO) is becoming very popular. EMS and pre-hospital are starting to use them after even 1-2 failed IV attempts. I know I use them often in the Emergency departments when I need fast access or a second line, quickly. A lot of fantastic data is coming from the military and shows just how safe, effective and fast these devices are.
Below is a video of IO access using the E-Z IO brand “gun” manufactured by Vidacare. I have personally used this device on numerous times and found it very easy. My only complaint is the weight and size of the device which is a consideration when carried in a pack or vest.
Next is a Sternal Access IO that goes by the trade name FAST and manufactured by Pyng. This system is very light and portable but requires a bit more technique to insert, in my opinion. Also, this system requires manual strength to pierce the sternum.
Lastly, we have the B.I.G (bone injection gun) manufactured by Persys. This system uses a spring loaded firing mechanism but still retains a small size, portability and low weight.
There are a few things that are common to all IO devices and that is what can be administered through them and concern for patient comfort. It is important to note that ALL medications given Intravenously can be given through an IO. This includes cardiac drugs, fluid and antibiotics. This even includes contrast medium for CT scans!
As for patient comfort, a small pre-load of lidocaine 1% will help decrease the ache associated with infusion of fluid through an IO. This pain from infusion is due to the swelling of the bone which occurs while liquids are being infused through the medullary cavity. I typically pre-fill the IV tubing with lidocaine and then infuse as normal, allowing the first 1-2 cm of lidocaine filled tubing to flush in first, ahead of the fluid.
Lastly, it is important to note that all IO access will require much greater pressure to infuse as compared to intravenous access sites. Typically, I use a pressure infusion bag that is commonly used in a trauma setting. In a tough spot, a blood pressure cuff has been inflated around the IV bag and provided the necessary pressure to infuse. When giving an injection of a medication from a syringe, remember that this extra pressure is necessary and normal with the IO access device.
A good basic primer on Intraosseous use can be found here, courtesy of Emedicine.
A nice review of military thoughts on IO access can be read here, courtesy of Military Medicine.