Intraosseous Access Simplified: Tips for Saving Lives

This transcript has been edited for clarity. 
Robert D. Glatter, MD: Hi and welcome. I’m Dr Robert Glatter, medical advisor for Medscape Emergency Medicine. Joining me today to discuss the outcomes of distal femoral vs tibial vs proximal humeral intraosseous (IO) catheter placement in nontraumatic out-of-hospital cardiac arrest in adults is Dr Peter Antevy, pediatric emergency physician and medical director of Coral Springs–Parkland Fire Department in Palm Beach County, Florida.
Also joining me is Dr David Miramontes, assistant clinical professor of emergency medicine at University of Texas Health Science Center in San Antonio. He’s also serving as the medical director for the City of San Antonio Fire Department. 
I want to welcome both of you to this discussion about site-specific IO needle placement, how it matters and where it matters, especially in the setting of out-of-hospital cardiac arrest.
Peter, I’d like to begin with you. Describe your experience in the setting of out-of-hospital cardiac arrest. You have a patient in extremis. How do you approach this patient? Also, we can talk about shockable vs nonshockable rhythms. 
Peter M. Antevy, MD: Rob, thanks for having me. Cardiac arrest in the out-of-hospital setting is very important. It’s a very choreographed event, and obviously, we go through our progression. Let’s just focus on access at this point in time. 
Rather than messing around and looking for an IV and so on, we have made it a protocol that we go right to IO access. That has been something that we know we can get, we know where to go, and we know how long it’s going to take. I can take a stopwatch and from the moment we say “go,” I know when that IO is going to be in. That’s how exact we are with our timing, and it’s really faster than we can put an IV in. 
Glatter: David, is your experience the same or do you approach that differently? 
David A. Miramontes, MD: We’ve been doing the IO portion as part of our cardiac arrest management for some time. One of the big reasons is logistics — location, location, location.
We have a bunch of people at the head of the bed in a cardiac arrest, we have two people doing airway, and we have someone doing compressions. We also have someone that is starting to put the monitor on. That’s a lot of people at the head of the bed. 
What we decided is that, logistically, it makes sense to use the distal femur as our “med board” because it’s on the other side of the patient and everybody’s out of the way. That works really well for us. 
Now, if you can get a good antecubital IV, great. That’s what you should use. But if you can’t get it on the first click, you should go right to IO, if that’s not even the first thing you should do. 
In my system, my emergency medical dispatch (EMDs) do IOs. Many times, the first arriving engine has already got the i-gel in, they’ve already defibrillated, and they’ve already got the IO in place. If there is a medic on there, they’ll start the medication therapy right from the engine or the truck, and then when the medics get there from the ambulance, they continue with the rest of the protocol.
For us, the IO is all about location, location, location. It’s out of the way of our choreographed, pit crew style of care. 
Glatter: Does the rhythm matter — whether there’s a shockable vs nonshockable rhythm — in your approach, site specific? 
Antevy: That’s a great question. Years ago, at the National Association of EMS Physicians (NAEMSP) during the oral abstracts, Mohamud Daya, MD, presented some data that, when I first heard it, I didn’t believe a word of it, which was that if you give amiodarone or lidocaine through an IO, the outcomes are worse than if you would have given it through the IV. I let that sink in a little bit, but it didn’t really change much practice. His paper came out in 2021. I read it and said, “Okay, I still want to see more.” 
Then another paper came out, in 2023, which said the same exact thing. Rob, I have to admit that, based on what I’ve seen there, and we can discuss the data if you’d like, I’ve now modified my protocol. If it’s a shockable rhythm, it’s preferable — I don’t make it mandatory — but it’s preferable to get an IV over an IO. 
We can discuss the reasons for that physiologically — at least the ones that I’ve made up in my mind as to how to explain the physiology — but yes, I’ve made that change. 
Glatter: David, is that your current approach or would you differ? 
Miramontes: Kind of. We have a little different way of dealing with shockable rhythms. If it’s a v-fib/v-tach, we have a “shock, call, go” protocol, where we take the patients to an ECMO center. We’re not giving any meds. 
Yes, I said that. We are not giving any meds. No epinephrine, unless they don’t have a pulse with LUCAS CPR. We’re not giving amiodarone because oftentimes we shock them to asystole and then the guys at the hospital won’t put them on pump and they won’t go into the program.
If we were going to give any kind of medications, we would use bicarbonate, and that’s to work the protocol so their pH is above 7 so they can go on pump.
Right now, we are using the femoral IO most of the time. The data that we’re going to be talking about are rather compelling to rethink that.
As Peter said, the amiodarone or lidocaine, it may have to do with the lipophilicity of the drug, and it doesn’t get through the fatty bone marrow. We don’t know. I think there’s a signal. I don’t know that it’s absolute, but it’s concerning that we should probably rethink what we’re doing.
Glatter: Absolutely. In the setting of refractory v-fib/pulseless v-tach, in those situations, you shock them multiple times and if nothing’s happening, you’re going to the ECMO center.
Miramontes: It’s “shock, call the medical director, go.” It’s very quick. After one shock, we’re doing basic airway skills, loading, and getting them going to the ECMO center. 
The meds, like I said, are not really helping us, to be honest with you. In fact, they’re probably hurting us. We know from the PARAMEDIC2 trial that epinephrine may cause worsening ischemia in the brain.
The amiodarone is not going to work if the patient is in recurrent v-fib or v-tach because their left main is clogged. Until you open up that vessel, we’re not going to have a good outcome. 
Antevy: People who are listening today need to understand that many of the recommendations that are put out in ACLS (eg, the epinephrine research is based on puppies back in the 1960s and 1970s), and many of the things that we do today, really don’t have a basis in science. 
Similar to what Dave is doing, we’ve also removed epinephrine from our shockable rhythm protocol and our outcomes are phenomenal. We’ve added esmolol, and we use double sequential for the refractory cases.
What you’ve seen in the past 5-10 years is that in EMS, there are many people doing different things, but I think as long as you’re following the science, and you’re actually monitoring your outcomes and then publishing what you do, I think that’s the right way to go. I don’t see a randomized controlled trial coming anytime soon to answer many of these questions, so that’s the fascinating part about this whole thing.
Glatter: In terms of getting patients to ECMO centers where you’re located in Palm Beach, how does that pan out? 
Antevy: I’m also down here in Broward County and ECMO is for a very specific type of patient. The reason that I’m sure Dave has the “call the doctor” aspect of it is because if it’s not an ECMO-type patient with respect to age, were they witnessed or not, what was their no-flow time, and ultimately, they need a lactate level. There are all these characteristics to consider. You end up having a small number of people. 
In each area, you’re not going to have tons of ECMO centers. You’ll probably have one. We have one ECMO center here in Broward County and we have had several saves. 
We had a 55-year-old guy named Gary, refractory VF, and Memorial Hospital saved his life with ECMO. Those are very few and far between, and so I think that communities will have to see if the juice is worth the squeeze. 
If your hospital is already an ECMO center and they have ECMO for all these other things, the question is, can they do ECMO in the emergency department 24/7? Are they going to bring you those resources when you need them in the middle of the night? If the answer is yes, then if a patient’s in refractory VF, you should go there quickly. I would agree with David on that wholeheartedly.
Glatter: We talk about anatomic landmarks and ease of placement of proximal humeral vs a distal femoral IO. Where do you feel the skill can be acquired more easily? Do you find that people are more afraid of the humerus based on the anatomy? Do they prefer the distal femur? What are you finding in your systems?
Miramontes: Again, for us it’s logistics. The distal femur, as long as you keep the legs straight, you’re good to go. Most of the time, when you’re moving a patient, they’re going to be on a backboard or a stretcher, and the legs can stay straight, so we’re good. 
Now, the humerus, on the other hand, if you look at me, I’ve got my arms up on the LUCAS and what’s sticking out? You got sticking out that big old humoral yellow EZ-IO needle, and all you have to do is touch it once and it’s done. That’s a huge issue if you’re moving patients. It doesn’t stay in very well. Yes, they have the holder, but that holder does not hold if you whack it taking a patient out into the hallway, for example. That’s one of the issues with the humerus. 
Is the humerus harder to put in? If you teach your team really well and you have a cadaver lab, then it’s not that bad. I think the distal femur is even easier, especially in kids. It’s all about logistics in our world. Do I use the humerus? I use it all the time in sepsis patients and overweight patients. I think that’s a great place to go, but for us in cardiac arrest, it’s the femur.
Glatter: In animal and some human studies, looking at inferior vena cava vs superior vena cava in terms of where you’re putting the catheter (eg, the proximal humerus vs the distal femur) and getting the medicine where it needs to be, there is a difference. Would you agree? 
Miramontes: I would totally agree. We know that medicines given in the humerus get to the central circulation much quicker. We can see this in the lab. You flow that and that subclavian vein just balloons out. That is true. You have to balance that with logistics, patient movement, and those types of factors. That’s why I’m a big proximal humerus guy for sepsis and for other types of medical cases where that works.
Let’s not forget about trauma. If you’ve got trauma below the nipple line, you should not be doing a femoral IO. You should be in the humerus. There are advantages and disadvantages to both sites, and you have to weigh the pluses and minuses of both. 
Glatter: In small critical-access hospitals where a fair number of transfers come, for ease of transport, going distal femur makes sense based on location, if there is trauma, or if it’s a medical case. Would you both agree on that for long transport times? 
Miramontes: I would agree. 
Antevy: Just to put a pin on the pediatrics side because David mentioned it. David’s group did a great study on the distal femur IO in adults and everybody should read that study. What I found fascinating about his study is that, once they allowed the distal femur, you saw all the paramedics shift over to that. That was without an arm twist. That was because they knew, like he said, it was logistics, it was easier to do, and they liked it better. 
In children, for many years, people used the proximal tibia. There were data back in 2019 out of Resuscitation showing that 47% of the proximal tibial IOs were malpositioned in infants, and 39% were malpositioned in children older than a year. That’s a very high number. 
When you look at the distal femur IO, it’s so easy to place and the cortex is thicker. When that needle gets into that cortex, it’s not coming out, unlike what David said about the other one — that you can just flick them and they come out.
I’m happy to say that we submitted our paper and it was published in Prehospital Emergency Care, where we have the first paper on the distal femur IO in pediatrics with a 90% success rate. Once our crews do it once, they’re never going back. For pediatrics, I think it’s a no-brainer and people should abandon the proximal tibia completely, in my opinion. 
In adults, I think now you have options. The proximal humerus and distal femur are both great options. 
Pediatric Considerations in Intraosseous Access
Glatter: Is there any issue with growth plates in pediatrics or any issue with bone or the cortex, in terms of resilience, that you’re seeing years later? Any follow-up to that?
Antevy: The common teaching is that you want to stay away from the growth plate. It’s much easier to hit the growth plate when you’re going proximal tibia, and that’s why they want you to angle away from the growth plate. 
When you’re going with the distal femur, Rob, if you look at a photo of the anatomy, if you’re a centimeter or two above the patella at the midline and you hit that bone, you’re very far from the growth plate.
If you angle inferiorly and you are aiming toward the growth plate, you’re going to hit it, but I would say the distal femur is much safer. I’ve never seen a follow-up study on IO gone wrong in children. I’m sure there are cases of it, but it’s never been reported, to my knowledge.
Glatter: How about you, David? Any complications with IO catheter placement? 
Miramontes: I’m just going to reiterate that the proximal tibia is not a good place. If you get it wrong, you’re going to cause a compartment syndrome in that lower leg. That’s a problem. 
Now, if you get it wrong in the femoral space, there’s way more room if you’ve infused fluid or medicines in that fascial space, and you will not have a compartment syndrome there. You’d have to angle underneath the patella to get into the growth plate. I just don’t see that happening, especially if the leg is extended. The patella rides up, so it basically covers up the place you don’t want to be. 
Glatter: Any pearls that each of you have to summarize and wrap up? 
Miramontes: If you’re in a rural ER and you’re having problems with access, you shouldn’t even flinch. You should just go ahead and establish access. If you’re going to give fluids and vasopressors and get the patient better, chances are you’re going to pop up a great vein, the brachial vein or antecubital space later after the resuscitation is started. Now you have two lines, right? Or you can put one of the rapid-infusion catheters in the brachial space or something like that. I wouldn’t even flinch using an IO. 
I think the distal femur is great. There are questions about using that spot with certain drugs, like amiodarone and lidocaine.The data are pointing in a direction there, as a signal, and it makes me pause and think. I’m glad Peter has flipped away from that. When all is said and done, the best thing is a good large-bore IV in a vein. If that’s not available, just drill them. 
Antevy: What I would add on is, for the pediatric cases, some very important information here is that EZ-IO needle. Again, I have no conflicts of interest; it’s just the one that we use. The reason it got a patent so many years ago is because it’s a cutting needle. When you look at the edge of that needle, it’s like a knife.
If you have a newborn, a 1-month-old, a 2-month-old, you should not use a drill. Whether you’re going to choose the distal femur or the proximal tibia, just use your hand. Because the bone is so soft, I’ve seen people use a drill and it just goes right through that bone. In the very young infant, use your hand.
The second pearl is that everybody says, “Wait, this distal femur thing is great; how do I train on it?” I’ve been in contact with two specific people for years and with Teleflex, to try to get a distal femur trainer. I’m happy to say that it’s finally available. Both people have come out with them at the same time, and we finally got our hands on 10 trainers and we absolutely love them. If you’re going to go distal femur, finally now, you can get access to a trainer so that you can train on it and then convert your entire agency away from the proximal tibia. 
Lastly, I’ll say that there’s a rumor that they’re now going to have a 65-mm needle. The 25 mm is the blue and the 45 mm is the yellow, which is the largest we’ve had. Dave has been using the distal femur on these large adults for a long time and he needs a bigger one. Apparently, there’s a 65-mm green coming out. Dave, I don’t know if you know about that. They’re probably going to give it to you first!
Miramontes: For our bariatric patients, we actually do cut-down IOs. We cut down through skin, we cut down through fat to the fascial plane, and then we drill.If you’ve got that problem, that’s an option, and now, apparently, we’re going to have a bariatric needle available for that. 
Glatter: Well, it’s about time. That’s a real challenge. With many patients, I’ve experienced the same thing. The needle isn’t long enough and then you’re having a very difficult time getting access. That’s very important.
Antevy: Dave is selling himself short. He’s got probably the most premier EMS system in the country. It’s always interesting to hear what he’s doing in Texas.
Glatter: I also want to mention that you’re both members of the EMS Eagles Global Alliance, Dr Paul Pepe’s premier prehospital resuscitation expert panel.
I appreciate your time. This is such an important topic because getting that access in critically ill patients really matters. It’s time and organ preservation, as you all know. Thank you so much for your expertise here.
Robert D. Glatter, MD, is an assistant professor of emergency medicine at Zucker School of Medicine at Hofstra/Northwell in Hempstead, New York. He is a medical advisor for Medscape and hosts the Hot Topics in EM series. 
Peter M. Antevy, MD, is a pediatric emergency medicine physician and medical director for Davie Fire Rescue and Coral Springs–Parkland Fire Department in Florida. 
David A. Miramontes, MD, is an assistant clinical professor of emergency medicine at University of Texas Health Science Center-San Antonio, School of Health Professions in the Department of Emergency Health Sciences. He’s also serving as the medical director for the City of San Antonio Fire Department. He is responsible for medical oversight, training, quality assurance, and disaster preparedness, and he coordinates the provision of EMS medical care with area hospitals.