Sharp Waves: ILAE's epilepsy podcast
Sharp Waves: ILAE's epilepsy podcast
Emergency diagnosis and treatment of status epilepticus
As a neurological emergency, status epilepticus (SE) requires timely diagnosis and treatment. A US study found that 10% of people with SE were not diagnosed by emergency services. Among those who were diagnosed in an ambulance, 20% did not receive any first-line treatment, while others received lower-than-recommended doses. Sharp Waves spoke to senior author Dr. Elan Guterman about the study.
Publications mentioned during the conversation:
Emergency response to out-of-hospital status epilepticus | Neurology
Sharp Waves episodes are meant for informational purposes only, and not as clinical or medical advice.
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[00:00:00] Nancy Volkers: This episode of Sharp Waves looks at a study of prehospital identification and treatment of status epilepticus in more than 1,200 patients. Most were diagnosed by emergency services, but only some of them received first line treatment on their way to the hospital. Those not diagnosed by emergency services received later treatment and lower doses.
We talked with the study's senior author about the results.
[00:00:27] Dr. Elan Guterman: Thanks so much for having me on Sharp Waves. My name's Elan Guterman; I am an Associate Professor of Neurology at the University of California in San Francisco.
I have subspecialty training and work as a neurohospitalist. So clinically, I care for patients with a wide range of neurologic conditions, although all of them are either in the emergency department or admitted to the hospital or the ICU.
A large part of my clinical work focuses on patients with neurologic emergencies, such as status epilepticus. And the clinical experience naturally has driven my research in thinking about how we can optimize care for patients with status epilepticus and other neurologic emergencies.
A hallmark of all medical emergencies is we really need to get patients treated as quickly as possible if we want to improve outcomes. So, for status epilepticus, every minute really makes a difference in terms of the likelihood of seizures being controlled.
I was actually drawn to medicine in part because I worked as a ski patroller during college, and that experience gave me exposure to the challenges of delivering care outside the hospital. As I started circling around ways to improve care for these patients with neurologic emergencies. I was quick, I think, to look beyond the hospital to the prehospital world of emergency medical services.
And so now, much of my research focuses on identifying who is being missed before they arrive to the hospital and developing methods to diagnose and treat them more quickly in order to improve outcomes. This study that we'll talk about was really laying the groundwork to understand how big the problem really is.
[00:02:21] Nancy Volkers: Excellent. Thank you. So, can you talk a little bit about the data you used in the study and how you identified patients to be included or excluded?
[00:02:32] Dr. Elan Guterman: So, one piece of or one fact that I realized had changed around doing research on emergency medical services is in the past, they would use all of these pink carbon-copy sheets that were really hard to do research on. More recently, they have gone the way of hospitals and transition to electronic medical records.
In addition to that, there's been a recent push to improve the interoperability of the EMS medical records and the hospital medical records. So paramedics can get feedback about what's happening in the hospital, from the visit or the hospital stay. And it is also opened up an opportunity to better understand the patient trajectory during their prehospital and hospital care by building research data sets from those electronic medical records.
I used in particular a research data set from ESO, which is a widely used EMR software provider in the United States. As mentioned, there's a subset of hospitals that actually provide ESO with hospital outcome data, and then they link that into a research data set that can give you insight into what somebody's prehospital care looks like, both the agency characteristics and the clinical features of the actual encounter or 911 call, and then gives you some information from what's going on in the hospital.
So that data became an opportunity to really understand the question of who is being missed with status epilepticus more broadly across the U. S. because so many agencies are now participating in this electronic medical record.
[00:04:24] Nancy Volkers: Great. Thank you. So what was the data set? Did it encompass a certain number of years? How many encounters are we talking about?
[00:04:33] Dr. Elan Guterman: We looked specifically between the years of 2019 and 2021. We focused on the group of agencies and hospitals that are participating in this health data exchange. So EMS may provide software for 5 to 10 percent of EMS agencies in the U.S., but only a subset of them are actually participating in this health data exchange with hospital information.
And then from that, we identified all of the patients who were diagnosed with status epilepticus as their primary diagnosis in the emergency department. That made up about 1,300 encounters.
Our main goal was really to understand how often our patients with status epilepticus are having their seizures and status missed by EMS during their 911 call, and then what are the downstream consequences of that?
So one challenge for all of us who are using electronic medical record data to identify patients is we're forced to rely on coding, and these codes that ED physicians and hospital physicians use are imperfect.
We knew from the get-go that not all patients who were coded as having status epilepticus would truly meet clinical criteria. So I should add that we also took all those patients who were diagnosed with status epilepticus and then looked specifically at the group of patients who had poor mental status, which we defined as a Glasgow Coma Scale score of 8 or less, knowing that that would avoid diluting our study population with a whole bunch of people who we don't really think were having status epilepticus. Maybe they had a seizure and their seizure was missed by EMS. That's important, but doesn't have the same grave clinical consequences as somebody who's truly having continuous seizures.
So we tried to find this high-acuity patient population and then we used that to look back and understand one, what EMS was diagnosing and then two, how is EMS caring for these patients in association with that diagnosis.
The two outcomes that we looked at in terms of these downstream consequences were really focused on treatment for status. We were wanting to know, does time to treatment differ? So if an EMS provider diagnoses you with status epilepticus, we'd want them to treat you very quickly. But is there a subset of people who aren't diagnosed with status, perhaps because the EMS provider is not quite clear what's going on, but then they choose to give you a benzodiazepine just in case, are those patients still not getting the treatment they need, even though they're getting a benzodiazepine in the ambulance because that treatment is delayed?
And we also were curious about the dose of the benzodiazepine that the EMS provider was using at that time. Again, if you're not quite confident in your diagnosis, you wait a little bit of time and you give somebody a slightly lesser dose of the medication, which ultimately leads to the patient not getting the treatment that they need.
[00:08:13] Nancy Volkers: Thank you. So you have a group of patients that was diagnosed by EMS as having status epilepticus, and then I believe another group of patients that wasn't diagnosed but then ultimately diagnosed in the emergency department as having status epilepticus. So can you talk a little bit about findings between those two groups?
As far as that relates to the outcomes you were looking at.
[00:08:45] Dr. Elan Guterman: First, to think about how big the problem was, we found that just over 10 percent of patients who were diagnosed with status epilepticus in the emergency department did not have a diagnosis related to status epilepticus or seizure while they were being cared for by emergency medical services. So that is 10 percent of patients who are not receiving the diagnosis. And then among that group, we see that those who get a benzodiazepine, their treatment is delayed about four and a half minutes. So they're getting treated four and a half minutes later than somebody where EMS confidently diagnoses status epilepticus and puts it in the chart.
For this group, we focus specifically on those getting treated with midazolam because it was easier to align dosages across calls. Those who did not get diagnosed with seizures or status epilepticus in the ambulance had lower doses of midazolam. They were getting treated with a milligram less. So together they were being treated later and treated with less of a dose.
[00:10:08] Nancy Volkers: So you said about 10 percent of people who were ultimately diagnosed with status in the emergency department were not identified as having status by emergency services. Can you talk a little bit about what those people were diagnosed with, or what they maybe were treated for, if it wasn't status?
[00:10:32] Dr. Elan Guterman: The largest proportion of patients, it was about 40 percent of patients, ended up with a diagnosis of altered level of consciousness. So the EMS provider is picking up this patient is confused, their mental status is depressed, but they're not quite picking up on the fact that they are having seizures, either because of a lack of diagnostic confidence in making that determination or perhaps it's subtle clinical signs of status—subtle facial movements or twitching of the fingers being missed, or maybe something else.
And then the next most common were patients who were diagnosed with stroke instead. That made up just under a quarter of patients. And again, It shows, okay, the EMS provider perhaps is picking up that there is an asymmetry in somebody's clinical exam, diving first into the explanation that, “Oh, this must be a stroke” and missing status epilepticus, which is important because we have the tools to treat status epilepticus in the ambulance.
If it were all the same and patients were just getting to the hospital really quickly, then it wouldn't make much of a difference. Instead, by diagnosing somebody with stroke instead of status epilepticus, we're potentially missing a window for treatment.
I did gloss over just who's getting treated in general, which I'm happy to go into as well. Question 1 is, are you even getting a benzodiazepine in the first place? And the answer was that patients who were diagnosed with status epilepticus were 80 percent of the time being treated with a benzodiazepine during their 911 call while patients who were not diagnosed were treated 20 percent of the time, just underneath that, 19 percent.
So we're still actually finding patients who are not getting diagnosed with status epilepticus who are getting treated, but the number is significantly less.
[00:12:51] Nancy Volkers: And among those who are treated, the treatment comes later and the dose is lower.
[00:12:56] Dr. Elan Guterman: Exactly.
[00:12:57] Nancy Volkers: Okay, but even among those—you said that even among those who are diagnosed with status, 20 percent of them were not receiving first-line treatment at all until they got presumably to the emergency department.
[00:13:10] Dr. Elan Guterman: That is also correct. And it's a finding that has been shown by others looking at patients with status epilepticus in the ambulance. There are a group of patients who are not actually getting a prehospital benzodiazepine.
[00:13:28] Nancy Volkers: What are some of the speculations or theories about why that doesn't happen? If they're diagnosed with status epilepticus and first-line treatment is a benzodiazepine, why are they not receiving it?
[00:13:42] Dr. Elan Guterman: For me, one of the most helpful studies actually comes from the pediatric literature.
There, Manish Shah and his group, the first author was John Carey, published a qualitative study where they ask paramedics, what are the reasons why you would give a benzodiazepine or you wouldn't give a benzodiazepine? And there are a few different important factors that they identified through that study.
The factors include that paramedics are scared of the potential for respiratory depression after giving somebody a benzodiazepine. If you're not confident in your skills to intubate a patient and you're worried that the medication that you're going to give could then lead to a need for intubation, you're really stuck having to make the clinical judgment about what is safest in this situation.
We do have data from the PHTSE trial, which suggests that the greatest risk to patients with status is actually continuing to seize, because that itself causes more respiratory depression.
And so that becomes one conflict. The other is, especially on the pediatric front, that dosing is difficult, that weight-based dosing in kids for providers who are not seeing a lot of patients with seizures becomes tricky and then potentially unsafe and difficult to manage in the chaos of responding to a 911 call. So the opportunity can get missed.
And then finally, benzodiazepines are controlled substances, so they have all of these precautions to avoid any provider accessing this medication for any call, and those logistics can be another constraint to actually using the medications when we would clinically think that they are indicated.
[00:15:52] Nancy Volkers: So there's a lot of issues there. Thank you for spelling that out. And then you also mentioned earlier that lack of treatment, that every minute does make a difference. And I think quite a few studies have shown that the longer the delay, the potentially worse outcome. I know you cited a study that something like 57 percent of cases of status epilepticus were recognized prehospital. So, almost half were not. And then among the ones that were not, there was a higher risk of new deficits in those patients long term.
So, are there solutions to improve this issue? Since there's a lot of moving parts here, there's emergency services, which are split up very locally, and then there's hospitals, and there's training for different types of professionals. So what could sort of move the needle toward improving emergency treatment?
[00:16:55] Dr. Elan Guterman: I actually think that there are lots of potential solutions. But recently I've been focusing on one. I'll just say you mentioned provider training. Absolutely. We have to remember that as neurologists, we do years of specialty training and EMS providers, their neurology exam training and their training around neurologic diseases is significantly limited, not to mention the amount of time that they have to evaluate the patient is a lot less too.
However, one piece that I've noticed is even in the emergency room or in the hospital, there are circumstances where we are not sure whether a patient is seizing, and so even if you can improve somebody's physical exam skills and you can improve somebody's ability to get a clinical history in the hospital, we have the benefit of these advanced diagnostic tools.
And for status epilepticus, that's namely EEG. And so I do believe that just like we have an EKG to monitor our heart electrical activity, both in the hospital but now also in the ambulance, there is going to be an opportunity in the future to incorporate some form of an EEG into an ambulance. I think that could very much help this issue because it would give objective data in situations that are going to be clinically confusing, no matter who you are, and hopefully with the technology that's advancing and we are able to get EEGs that are easier to apply and faster to get data from that it will provide an opportunity to give EMS providers a tool to help them in these situations.
So that's my vision for the future. At least if not a moon shot, an ozone shot, getting outside the earth, getting outside our current reality and hoping that we can do a better job going forward, given the gaps that we found and the even larger gaps that were shown in the study that you just mentioned.
[00:19:17] Nancy Volkers: I'm assuming these 10 percent were people were not obviously in like convulsive status epilepticus, right?
[00:19:27] Dr. Elan Guterman: We did not look at whether the patients were in convulsive or non-convulsive status. We have the medic narrative, so there is potentially an opportunity to see how the EMS providers were describing what's going on on scene and what their exam was.
But the study that you had just mentioned, that was published in 2017 in Neurology by Semmlack et al., they were able to look at the differences between somebody who was in convulsive status and non-convulsive status. And just as you suspected, the majority of these patients, at least by the time they're reaching the emergency department, are in non-convulsive or subtle convulsive status epilepticus, which is harder to pick up.
So, if my future vision of getting EEG in every ambulance is going to take years, if not decades, hopefully years, but you never know, then there is always this question of how do you better equip people right now?
Another question that I've had is thinking about this from the lens of neurologic emergencies overall, and how are we doing this for other emergencies? So we can take stroke as an example, where there have been a lot more efforts to standardize EMS care overall, and one important piece of this has been the prehospital stroke scale. You're not just asking EMTs, paramedics to do a targeted neurologic exam, where you find neurology residents wondering, wait, what does this mean? How do I even condense my very extensive neurology exam into the most important elements right now? Instead, a prehospital stroke scale is saying “We want you to look for these five signs.” And that's it.
And so I think that there would be an opportunity for something like a prehospital seizure scale.
Again, standardizing and protocolizing assessments in a way that is actually very common within the prehospital world and within EMS care. Understanding exactly which of those exam elements to include, which would be highest yield, is still a scientific question that I am also hoping to answer at some point.
[00:22:02] Nancy Volkers: Excellent. Thank you. So my last couple of questions are, what's the take home message and what can neurologists do right now to help with this issue? I think you've sort of semi answered that—we need some sort of standardized scale that makes it easier to establish who might need this first-line treatment for status epilepticus.
But the second aspect is research. So in many areas of the world, emergency services is just like a transport vehicle or there isn't any emergency service and you have to be taken to the hospital by a family member. There isn't any prehospital care. How can research like the research that you're doing help clarify the importance of emergency treatment in neurology, which could provide evidence to help enhance emergency services care in areas that currently don't have any?
[00:23:02] Dr. Elan Guterman: I will answer that question, it's a great one, in perhaps two different ways. The first is where can our research efforts be focused? In addition to everything that I've already mentioned, one struggle with doing research around status epilepticus and seizures is we know that time to treatment makes a difference in terms of controlling status epilepticus, but I cannot tell you with confidence how that is going to impact your cognitive function 30 days later, 90 days later, what if you come back repeatedly for status epilepticus? What does the dose of status, what sort of toxicity does that status epilepticus exposure have down the line?
And I do think that those long-term outcomes would be really helpful for being able to communicate what the repercussions are of delaying treatment. Stopping seizure is important, but preventing cognitive impairment in the long term, which is something that somebody is going to be dealing with forever, that speaks to the potential risks if that if we were to find that would have a greater message than our research is able to show right now.
So that is one scientific ask. The second part of the question, I would hope that finding that and understanding these long-term consequences would provide the motivation to improve EMS services everywhere, but I do think that we just generally have struggled to build up health systems in a way that they could even respond to advances in science in a way that would get people treated faster.
So I also think that alongside that research needs to be research about health system strengthening in countries right now that don't have robust EMS services so that we can get patients treated with status epilepticus faster everywhere. In a way, we're lucky to be dealing with the problem that we have and that we have a standard that involves getting these patients treated even before they reach the hospital.
So getting every country to a point where they could do the same would be a tremendous leap. I would say overall that we can work on that right now, even without that extra piece of science around long-term outcomes.
[00:25:38] Nancy Volkers: Were there any other aspects of your study or just this issue in general that you wanted to mention that we haven't covered?
[00:25:45] Dr. Elan Guterman: One thing that I'll add is that the goal of this study was to understand who is being missed while they're receiving prehospital care. What I want everyone to understand is that for those who have not been on an ambulance and responding to these 911 calls, it is very difficult care to provide, and it can be very difficult to diagnose these patients because they have subtle signs, because their seizures are intermittent, because there's a lot of other things going on, and so this is in no way meant to say that the EMS providers are not doing enough. There are many patients with status epilepticus who are missed in the hospital and in the ICU too. It's just meant to look at the problem in a clinical context where getting people treated faster and getting people diagnosed faster would really make a difference.
So I want to just add that extra plug that I think that the care that's delivered in ambulances, it amazes me every time I get to go out on a ride along. I think this is about finding ways to help EMS providers do an even better job than the job they're doing right now.
[00:27:06] Nancy Volkers: Great. Thank you for making that point. I appreciate that you added at the end that you know, emergency services can only do so much. They can't be all the specialists rolled into one.
I'm assuming you've talked to a lot of first responders. Do you, do you ever talk to them about what would help them from their perspective? Because sometimes I feel like, I'm not saying this is your research at all, I'm just saying sometimes when research is done without asking the people that are involved, then it's hard to find a solution.
[00:27:38] Dr. Elan Guterman: Yes, I am thankful that right here at UCSF, both the San Francisco Fire Department and the Alameda County EMS services are, are pretty close to the university there. They have medical directors who are also faculty. So I have a strong line of communication and collaborators and that has been an important gut check in terms of what ideas make sense versus not and yeah, it's definitely an important piece.
[00:28:14] Nancy Volkers: I really appreciate you coming on the show. Thank you so much.
[00:28:18] Dr. Elan Guterman: Thanks for having me. It was a great opportunity to share the work we've been doing.