Emerge in EM

E6: Submerge-Paper Deep Dive: Prehospital stroke severity scales and Door-To-Puncture times

• Mohamed Hagahmed

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In this episode of the EMERGE Podcast, I'm joined by Dr. Jon McMahon, an EMS fellow, to discuss the significance of a paper analyzing the impact of prehospital stroke severity scales in stroke patients. Dr. McMahon shares his background and highlights the importance of EMS in improving door-to-puncture times for stroke patients. We delve into the details of the study, which uses the Cincinnati Prehospital Stroke Scale and MRACE score to assess stroke severity and prioritize treatment. The discussion emphasizes the importance of rapid intervention to save neurons in stroke patients, the challenges of maintaining staff readiness, and the need for consistent training and documentation in EMS. The episode underlines the critical role of EMS in early stroke assessment and the call for continual quality improvement in prehospital care.

Paper source: https://jnis.bmj.com/content/early/2024/09/18/jnis-2024-022122

Dr. Hagahmed:

Hey folks, welcome to the emerge podcast. Today we'll be discussing another, paper this time in the Prehospital setting. And I have my friend Jon McMahon. Dr. McMahon, thanks for joining us. So can you tell us a little bit about yourself? And I'm just curious why we picked this paper and what's its significance for us.

Dr. McMahon:

Sure thank you so much for having me. First of all, my name is John McMahon. I am an EMS fellow over here at UPMC. I did an EM and IM residency at SUNY Downstate in Kings County for the last five years and wanted to continue my training in something that got me started in medicine, which is EMS. And it's been an incredible time over here. Originally from Long Island. So it's my first time out in Pittsburgh, which has been an awesome transition and everyone's been very welcoming and I've loved the area so far. In my mind, the first and most important part is that. It shows that EMS makes a difference. I will admit that there is some recency bias here. A couple of our colleagues are some of the authors on this paper. And they, in my mind, have done an incredible job of analyzing the data that was available to them.

Dr. Hagahmed:

The paper that we are discussing today titled Acquisition of Prehospital Stroke Severity Scale is associated with shorter door to puncture times in patients. with Prehospital notifications transported directly to a thrombectomy center. That's a long title. Honestly, I love reading papers that shows what we do in a prehospital setting creates an impact in these patients when they come to the hospital. So tell us a little bit more. Why is this topic important for us?

Dr. McMahon:

Sure. So I think the most important thing is like you said what we do matters, and I think this kind of builds on that data that shows that what we do matters. The fact that it's the idea is that door to mechanical thrombectomy time is going to lead to less brain cells that are dead. I feel like the old adage is time is heart was what we were talking about when we talked about STEMIs. And the same is true for the brain. I think that the latest literature was saying 1. 9 million neurons are dead every minute, which is pretty incredible. And obviously just like the cardiac cells, those don't come back. And those things that we can't, those are things that we can't replace. Until the data and the science gets much better, obviously, so making sure that someone can get to an intervention as fast as possible is super, super important. And I think another thing that's super important is also the fact that we identify those patients that are going to benefit from the thrombectomy itself. And I think the paper does a really great job explaining why the thrombectomy is important in that certain subclass of patients as well.

Dr. Hagahmed:

So when we talk about prehospital stroke severity scales, I know there's all these confusing names, Cincinnati RACE, MRACE. Can you tell us a little bit more about that? Why do we need to care about these scores?

Dr. McMahon:

That's a really important question. So in our region and an hour in our state in Pennsylvania, we use the Cincinnati Prehospital stroke scale as a screening. We want to see which of these patients may have a stroke. And based off of that, we want to see how serious that stroke is. We took the race score, which was validated. In several studies in the past and then modified it a little bit just to add some speech component to that and then Based on the points that they get the higher the score the more devastating the stroke can be And the higher chance that they're going to need a mechanical thrombectomy What's interesting that the study points out, too, is that in our region, we have several air EMS agencies as well, not just ground, which I think is really important whenever we're talking about EMS studies. Is this like my area? Is this like my region? In the air EMS, they do an actual NIH stroke scale, which we know is very popular in the emergency department. And then the ground is more of the MRACE score, which we just talked about. So the higher the number on both of those scales, the more devastating the stroke may be. So our goal is based off of that. How do we make sure that we get to that intervention as fast as possible?

Dr. Hagahmed:

And, we care about LVOs, right? We care about patients, specific subset of patient population. Who suffer from a large vessel occlusion that can be amenable to thrombectomy, but we still also care about that subset of patients who present within the four and a half hours.

Dr. McMahon:

I think something that a big push that we're having in our region in our system right now is identifying those patients that may be in that four and a half hour window, but wouldn't be a candidate for TNK or whatever your local thrombolytic maybe whatever flavor you got. So I think that's an important part as we talk about the education and stuff, identifying those patient populations that. While they're within that thrombolytic window that they can't get those and they have to be going to a comprehensive stroke center that's mechanically thrombectomy capable.

Dr. Hagahmed:

And it's important to note in this paper specifically, these patients were taken by EMS to a comprehensive stroke center. This was not a community hospital. This was a comprehensive hospital. level one stroke center that has thrombectomy capabilities. And they found that Prehospital stroke scales were associated with reduced door to puncture time. This is by a median of eight minutes. Is that significant?

Dr. McMahon:

So that, yeah, that eight minutes that you bring up is really important. I think in terms of, like we said, the number of neurons that are saved, I think the authors did a really good job of trying to eliminate all those situations where it would be impossible to get those eight minutes. And unfortunately, in the end, their analysis show that the eight minutes didn't really change the outcomes of the patients As a whole, but I think they did a good job of understanding, where can we improve? I think that was a big part of this paper is identifying like, where are the holes in our system and how can we improve the system as a whole? As well.

Dr. Hagahmed:

Dr. McMahon, you and I both work in a primary stroke center and a thrombectomy center. And as, just getting that stroke alert by EMS we have to be prepared. We have to get the staff ready. We have to get the scanner ready get that patient out of there, get the stroke patient in there. So sometimes we don't have the capabilities to operationally like care for these stroke patients, especially when the ED is very busy. So it's nice to know that we are getting a large vessel occlusion The study also identified after hours presentation and non compliance. AHA level one criteria as factors for prolonging door to puncture. What's your perspective on these challenges?

Dr. McMahon:

Yeah. I think the challenges are real. I think having folks in house during business hours some would call it banking hours. You're going to have the highest chance of making sure that CT scanner is spun up, making sure the whole OR team is there making sure that the interventional suite is ready which is another piece to the puzzle that we have to think about another whole scanner that we have to worry about as well. It's, I think it's super important that we, get those things rolling as soon as possible. Like you identified. The other thing that they had mentioned was those level 1 AHA criteria I think it's a good point is, if we're not meeting all the level one AHA criteria, maybe we are not thinking about stroke or it's not in the front of our mind the entire time. They identified a couple of the patients in the exclusion criteria is that they actually saw, even though they had an LVO, it took a little bit of time to identify whether that was, they were, A trauma at the same time, and we worried about trauma right away, whether it was it just didn't come up in the diagnosis fast enough, but they found it subsequently. And those patients were excluded from the study, but I found it very interesting that of the 236, I think, patients that they had around 20 or 30 were excluded for those two reasons.

Dr. Hagahmed:

And, honestly, I feel like these systemic challenges with, getting the staff to be available 24 seven, it's, It says that we have a modifiable factor, which is Prehospital, stroke scale notification and detection early, because that we can control, obviously, the hospital has to pay extra money to get more staff at 24 seven, and that's, that, that might, that change might take time. However, you and I as EMS medical directors, we have the ability to modify at least a Prehospital setting so we can at least. Improve the process on that end.

Dr. McMahon:

Sure.

Dr. Hagahmed:

looking into the data and we can dive deeper into this. The study reported 62 percent of delays had no clear documentation. First of all, documentation by who and what's the significance documentation by EMS or by us in the ed, or is it both?

Dr. McMahon:

That's a good question. Based on what I was reading, it seems like there is a national or a registry that was created for these stroke patients, and they had mentioned that there really isn't a section to document where the delay was. I think they identify it very well that if we don't understand where our delays are, we're never going to make them better. Just like you said. I think that would be on the end of the hospital itself to make sure that registry is stated up to date. I think on our end from EMS side of things, we can make sure that our documentation in the chart On our end is obviously up to date as well. I find it also very interesting that in some of these cases we did not have an MRACE score documented found immediately on transfer. So one of the ways that a local agency in the area has solved that problem is they do like an old school MCI triage tag kind of situation. where they just write the patient's name, the patient's next of kin and contact information if there is available, and then last known well time because they also identified that there was another thing that kind of led to the issue and delay was the fact that we couldn't make a judgment of when the last known was and what the symptoms were. And That family member or that staff member at a nursing home or whatever it may be was crucial in making the decision to go to thrombectomy and without that person or with that person's information faster, we could actually make that decision faster. So it's very interesting way to combat that system issue on the EMS side of things and super low tech. I'm not sure you can. I'm sure there's an app for it out there, but it is. It is incredibly effective way to make sure we're communicating with our colleagues in the emergency department. Silence.

Dr. Hagahmed:

So maybe I feel like this is exactly where Prehospital clinicians can step up and play a role in maybe facilitating. or trying at least to reduce those number of delays. Now you talked about AI and I know you and I probably use some of the tools for example, in my, one of my community hospitals here in Pittsburgh, we use an AI app called Viz AI to identify thrombectomy patients quicker. So in this study specifically, did that also improve outcome or at least improve identification of these subset of patients?

Dr. McMahon:

So it's interestingly, it did not looking at the paper, they had a transition time where I think it was around 2022, if I remember correctly, they actually adopted this AI as an option to identify the LVOs and controlling for all the other things that they controlled for in their AI. analysis, it actually didn't make any difference in identifying those faster or getting to the door to puncture time, which I thought was interesting.

Dr. Hagahmed:

Yeah. So we use it in our hospital system, obviously we are not a thrombectomy hospital. We are primary strokes in a hospital. So TNK capable. So the my experience is that app, that visit AI app actually improved quick detection of thrombectomy patients, but we still need to transfer them out to a thrombectomy center that has additional, delay in that. But speaking of readiness, speaking of preparation, how do you think we as EMS medical directors can actually, improve the EMS system ensure that there is a universal implementation of these Prehospital severity or stroke scales?

Dr. McMahon:

That is a great question. It's probably the one that we have to answer the most. And I'll be, I'll get there. The, I think it really lies in training. I think it comes down to training. And I know when I did EMS I relied on training heavily. It was one of my favorite parts. It was luckily an assistant chief in one of my agencies. And that was my focus for everybody. If you can train people to get these things down, Pat, I think we can make a huge difference. And that starts at a systems level from an EMS point of view too. I remember distinctly a situation I was at my volunteer fire department that I was a part of, and we just trained on stair chair, something as simple as let's just practice how to get a patient out of the house fast enough. And we did it a couple of times with a couple of our crew members. And then maybe an hour later, I kid you not, a stroke, concern for stroke comes out, found on the toilet left sided weakness, the whole thing, and we had to use the stair chair, and we were out into the hospital in 20 minutes, which if we had not done that local training right then and there, the just in time training, I don't know exactly how long we would have had to get her out, because we were coordinated, we were practicing the situation, Very well. Now that's just talking about the response and how we can get the patients out. I think also understanding the identification, making sure that we have reminder cards. I think some folks, some agencies use reminder cards or that's on the clipboard that they have, or it's on an app that they have on their phone or their tablet. Part of the crew can review that while we're actively undergoing the process. The resuscitation, if that may be, or the assessment that's going on. And I think the other part that needs to be done is making sure that we, like you identified earlier. Based on the assessments we do, the CPSS, the MRACE, the NIH, whatever it may be, we need to communicate that with the hospital as soon as we can. This is just going to make sure that, like we talked about from the beginning, the scanner gets spun up, the neurointerventionalist gets called up, the stroke team gets called up as well. Everybody's coordinating as soon as possible. But I think it's a, it's tough to right the ship, we got to make those slow turns every once in a while. I think the paper was really interesting in that they identified training is a tough thing, right? If you have a small aeromedical agency that the paper had used in the study, it's a small crew that you can easily get to. Versus if your agency is more of a volunteer organization where maybe they're not around all the time or you're a paid organization, but your medics work five different jobs in different places, and maybe you can't get constant CQI or training every week or every month or whatever it may be, it's going to be harder for those folks to get that message, get that training out. So figuring out a systemic way of making sure. People get the message multiple times and get that learned repetition over time. I think it's also going to be really important for what we can do as the medical directors.

Dr. Hagahmed:

Absolutely. So consistency, exposure are both key factors when it comes to prompt recognition of stroke and specifically LVO. And I feel also like documentation, like you mentioned, is also another crucial Not for us specifically as an EMS medical director, but also for them to see their improvement and we can discuss these cases where an LVO was missed and how we can improve on that. I do feel that this study definitely underscores the power of Prehospital care in shaping outcomes. in patients who suffered from an ischemic stroke or an LVO. I think it's a call for action for EMS clinicians, like both of us, and hospital systems to prioritize early assessment, robust communication, and continuation of quality improvement. I really enjoyed this conversation with you, Dr. McMahon. Thank you. And to our listeners. Thank you for tuning in. If you enjoyed this episode and podcast. Please don't forget to subscribe and leave us a review. Until next time. Take care.