Dr. Glatter: What you’re doing basically is resulting in an increase in cardiac output, essentially. That really is important, especially in these nonshockable rhythms, correct?
Dr. Pepe: Absolutely. As you’re doing this compression and you’re getting these intracranial pulse waves that are going up because they’re colliding up there. It could be even damaging in itself, but we’re seeing these intracranial raises. The intracranial pressure starts going up more and more over time. Also, peripherally in most people, you’re not getting good flow out there; then, your vasculature starts to relax. The arterials are starting to not get oxygen, so they don’t go out.
With this technique where we’re returning the pressure, we’re getting to 40% of normal now with the active compression-decompression CPR plus an impedance threshold device (ACD+ITD CPR) approach. Now, you add this, and you’re almost normalizing. In humans, even in these asystole patients, we’re seeing end-title CO2s which are generally in the 15-20 range with standard CPR are now up with ACD+ITD CPR in the 30%-40% range, where we’re getting through 30 or 40 end-tidal CO2s. Now, we’re seeing even the end-tidal CO2s moving up into the 40s and 50s. We know there’s a surrogate marker telling us that we are generating much better flows not only to the rest of the body, but most importantly, to the brain.
Dr. Glatter: Ryan, could you tell us about the approach in terms of on scene, what you’re doing and how you use the device itself? Maybe you could talk about the backpack that you developed with your fire department?
Ryan P. Quinn, BS, EMS: Our approach has always been to get to the patient quickly, like everybody’s approach on a cardiac arrest when you’re responding. We are an advanced life-support paramedic ambulance service through the fire department – we’re all cross-trained firefighter paramedics. Our first vehicle from the fire department is typically the ambulance. It’s smaller and a little quicker than the fire engine. Two paramedics are going to jump out with two backpacks. One has the automated compressive device (we use the Lucas), and the other one is the sequential patient lifting device, the EleGARD.
Our two paramedics are quick to the patient’s side, and once they make contact with the patient to verify pulseless cardiac arrest, they will unpack. One person will go right to compressions if there’s nobody on compressions already. Sometimes we have a first responder police officer with an automated external defibrillator (AED). We go right to the patient’s side, concentrate on compressions, and within 90 seconds to 2 minutes, we have our bags unpacked, we’ve got the devices turned on, patient lifted up, slid under the device, and we have a supraglottic airway that is placed within 15 seconds already premade with the ITD on top. We have a sealed airway that we can continue to compress with Dr. Pepe’s original discussion of building on what’s previously been shown to work.
Dr. Pepe: Let me make a comment about this. This is so important, what Ryan is saying, because it’s something we found during the study. It’s really a true pit-crew approach. You’re not only getting these materials, which you think you need a medical Sherpa for, but you don’t. They set it up and then when they open it up, it’s all laid out just exactly as you need it. It’s not just how fast you get there; it’s how fast you get this done.
When we look at all cases combined against high-performance systems that had some of the highest survival rates around, when we compare it to those, we found that overall, even if you looked at the ones that had over 20-minute responses, the odds ratios were still three to four times higher. It was impressive.
If you looked at it under 15 minutes, which is really reasonable for most systems that get there by the way, the average time that people start CPR in any system in these studies has been about 8 minutes if you actually start this thing, which takes about 2 minutes more for this new bundle of care with this triad, it’s almost 12-14 times higher in terms of the odds ratio. I’ve never seen anything like that where the higher end is over 100 in terms of your confidence intervals.
Ryan’s system did really well and is one of those with even higher levels of outcomes, mostly because they got it on quickly. It’s like the AED for nonshockables but better because you have a wider range of efficacy where it will work.
Dr. Glatter: When the elapsed time was less than 11 minutes, that seemed to be an inflection point in the study, is that correct? You saw that 11-fold higher incidence in terms of neurologically intact survival, is that correct?
Dr. Pepe: We picked that number because that was the median time to get it on board. Half the people were getting it within that time period. The fact that you have a larger window, we’re talking about 13- almost 14-fold improvements in outcome if it was under 15 minutes. It doesn’t matter about the 11 or the 12. It’s the faster you get it on board, the better off you are.
Dr. Glatter: What’s the next step in the process of doing trials and having implementation on a larger scale based on your Annals of Emergency Medicine study? Where do you go from here?
Dr. Pepe: I’ve come to find out there are many confounding variables. What was the quality of CPR? How did people ventilate? Did they give the breath and hold it? Did they give a large enough breath so that blood can go across the transpulmonary system? There are many confounding variables. That’s why I think, in the future, it’s going to be more of looking at things like propensity score matching because we know all the variables that change outcomes. I think that’s going to be a way for me.
The other thing is that we were looking at only 380 cases here. When this doubles up in numbers, as we accrue more cases around the country of people who are implementing this, these numbers I just quoted are going to go up much higher. Unwitnessed asystole is considered futile, and you just don’t get them back. To be able to get these folks back now, even if it’s a small percentage, and the fact that we know that we’re producing this better flow, is pretty striking.
I’m really impressed, and the main thing is to make sure people are educated about it. Number two is that they understand that it has to be done right. It cannot be done wrong or you’re not going to see the differences. Getting it done right is not only following the procedures, the sequence, and how you do it, but it also has to do with getting there quickly, including assigning the right people to put it on and having well-trained people who know what they’re doing.