Tuesday, July 21, 2009

Intraosseous Access Review for EMTs and Paramedics

The MedicCast EMS Podcast covers many topics for EMTs, paramedics and EMS students. In one episode Jamie Davis, the Podmedic covered the subject of intraosseous (IO) devices for paramedics and other ALS providers. Here is a portion of the episode transcript covering ongoing assessment of IO sites, securing and dressing IO access points on patients.

After IO Insertion and IO Assessment

There can be some adverse events that happen when placing and IO needle in a patient. You want to make sure you’re very careful in identifying your site and your landmarks. You want to make sure that you are being careful with your device. When you’re placing your needle, you don’t want to do anything that would twist or bend that needle during insertion that could cause it to break off. The needle can become clogged during administration, so you want to make sure that it’s patent, that you’re able to push fluids through it. Flush it with normal saline or lactated ringers per your protocol (usually 20 mL).

Just after insertion and before you flush with IV fluid or normal saline, you also want to make sure that you always draw back to look for blood or marrow return. Attach a syringe with a short piece of tubing or a stop-cock and a short piece of I.V. tubing. We want to see if we can draw back, just to see if we can see a little bit of bone marrow or blood coming back into it as a return. You may not always see that again because it’s thicker and you might not be able to withdraw bone marrow through the I.O. device, but that’s one thing to try to do to help verify correct placement.

It’s going to be a little harder to push fluids in and push medications in than you’re used to with I.V. placement because the bone marrow is not a purely liquid environment. It’s more of a solid, spongy material with liquid infusing through it. You’re going to need to use a pressure device to get fluids in. One of the things that we’re taught to use is to just wrap a blood pressure cuff around your bag and pump it up until you start seeing that it’s infusing through—and you’ll be counting your drips in the IV drip set just like normal but otherwise you will see that you just can’t seem to get the fluids or meds in if you don't apply additional pressure.

Pump up the cuff around the fluid bag until you start seeing drips in the drip chamber that shows that it’s flowing and that will give you an idea of what kind of pressure you need. Generally, you’re trying to overcome intraosseous blood pressure here.

Then go ahead and flush it with about 20 cc of I.V. fluid, saline or Ringer’s Lactate, and you want to make sure that this is flowing in cleanly. You want to look around the site for signs of extravasation, just like you would with an I.V. flush. You want to make sure that you actually are in the bone. If you weren’t in the bone or somehow becomes dislodged, you would see signs of puffing up around the skin, around the site, just like you normally would with an extravasated IV line. You also want to look on the back of the limb for signs that the IO needle has penetrated the far side of the bone.

In children, especially if you’re using a needle that might be a little large and even though you felt the pop of entry into the marrow space, you might have gone a little too far and you might have actually come out the other side of the bone in small children, you want to be very careful with that. You want to check the other side because you may actually have gone through and you’re pumping fluids out the other side of the bone. Again, look on both sides for extravasation.

IO Field Dressing and Stabilization

You want to stabilize an IO device just like you would any other impaled device or impaled object. Just like you have somebody with a stick through their arm, you would wrap it and stabilize it in place with some gauze rolls, or some pads, and tape it down very carefully to keep it stabilized and ensure that it’s perpendicular to the bone position, and then also make sure you secure your I.V. tubing very carefully as well. Again, you use a pressure device to infuse and you will go ahead and make sure that you follow through with re-assessing that regularly.

IO Complications

Complications that you see in IO placement in the EMS arena include local hematoma, and you’re going to have some bruising in the area, you may also have some compartment syndrome if you’re not careful. Frequent reassessment is the key. Come back and reassess to make sure you’re not pushing fluids in to the extravascular spaces, into the interstitial space and tissues, because obviously that will cause increased pressure locally and cause compartment syndrome in the localized area and eventually tissue death if you’re not careful. Significant amount of pain can be present with this particular intervention. You want to make sure that you are aware of that and as I said, I wouldn’t use this in any patient that is alert enough that they can complain about it.

One option that might not be the case is a serious burn patient where you have significant amount of burning in most of your regular I.V. access locations. I.O. access might be indicated and this patient may indeed be conscious. I would consult with medical direction. Make sure you follow your own protocols, but there may be a case where a severely burned patient without ready vascular access, I.O. may be indicated in a conscious patient. This would be an isolated and special case.

Other complications include growth plate injuries. The growth plate is that part of the bone that’s still growing in children. You want to make sure you’re using your landmarks and following your site guidelines carefully so that you can make sure you’re finding the site appropriately, but there can be a potential for problems if you are too close to the growth plate of the bone. There can be some other issues where there’s a fat embolism associated with this type of insertion.

--------

For more tips and medication reviews for EMTs, paramedics and EMS students check out all of the MedicCast EMS podcast episodes each week at MedicCast.com.

No comments: