S2:E6 - "Cardiac Arrest Controversies Part 1 – A discussion with Dr. Robert Swor about what we THINK we know about cardiac arrest and what we ACTUALLY know" - rec. September 21, 2020

In this episode, we welcome Dr. Robert Swor, an emergency center physician at Beaumont Hospital, Royal Oak, in Oakland County, Michigan. For over the last 20 years, or so, Dr. Swor has been a staple in the EMS community in Michigan.  Dr. Swor ALWAYS been deeply involved in EMS and cardiac arrest research.  He has a pretty impressive background when it comes to EMS cardiac arrest outcome data. 

Data provides us with an objective look at what is supposed to happen vs. what actually happened.  Sometimes, looking at the data from an objective perspective can reveal controversy regarding the, “best,” treatment options for cardiac arrest patients.  Bottom line, what we expect regarding how things work or how well they work isn’t always truth.  In this two-part discussion, we’ll discuss many of the controversies that find their way into the discussions of EMS providers and give you with hard facts, as their currently known.  Dr. Swor discusses on the data and related controversies regarding airway, breathing and ventilation in regard to EMS management of cardiac arrest.  In part 2, we’ll get into the details and data of compressions, blood flow and circulation.

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Transcript

Geoff Lassers  0:07  
Hello and welcome to the EMS on AIR podcast. The mission of this podcast is to keep healthcare providers safe, informed and prepared. Today is November 23 2020. I'm Geoff Lassers, and I'll be your host. This episode was recorded on September 21 2020. As you're aware Season 2 of the EMS on AIR podcast has been dedicated to stroke. But today we're changing things up a bit. Today we welcome Dr. swar and emergency center physician at Beaumont hospitals Royal Oak, right here in Oakland County, Michigan. For over the last 20 years or so. Dr. Swor has been a staple in the EMS community here in Michigan, especially Southeast Michigan, as long as I've known Doc, and it's been a long time. He's always been deeply involved in EMS and cardiac arrest research. He's got a pretty impressive background when it comes to EMS cardiac arrest outcome data. Data provides us with an objective look at what was supposed to happen. First, what actually happened. Sometimes looking at the data from an objective perspective can reveal controversy regarding the best treatment options for cardiac arrest patients bottom line, what we expect regarding how things work or how well they'll work isn't always truth. In this two part discussion, we'll discuss many of the controversies that find their way into the discussions of EMS providers and give you the hard facts as they're currently known. Today, Dr. Swor discusses the data and related controversies regarding airway, breathing, and ventilation in regard to EMS management of cardiac arrest patients. In part two, we'll get into the details and data of compressions, blood flow and circulation. Please keep emailing your questions, comments, feedback and episode ideas to the EMS on AIR podcast team by email at QI@ ocmca.org. Also, check out our updated website EMSonAIR.com. For the latest information, podcast episodes and other details. Follow us on Instagram @emsonair and please whatever podcast platform you use, subscribe to our podcast and leave us a rating and review. It really does help us to grow this thing. Enjoy the podcast. Dr. Swor. How are you today?

Dr. Robert Swor  2:10  
I'm good. Geoff, how are you?

Geoff Lassers  2:12  
Fantastic, can you give us an introduction of who you are where you do it. And a little bit of your background, sir.

Dr. Robert Swor  2:19  
I've been in an emergency physician at Beaumont Royal Oak since 1983. So this is my 38th year in practice. Somewhere early in my career, I got involved with the EMS. Actually, when I worked at Martin place hospital with the ALS crew there. Since then, I've been involved as part of my career working with EMS activities, was active in the Oakland County Medical control authority was the chair of the board for a period of years and have been involved with a number of other EMS activities, including the National Association of EMS physicians and the National Registry of EMTs. And part of my passion for this has been making good care better in the field, but also doing research in emergency medical services care. And that's kind of where I am these days.

Geoff Lassers  3:12  
And in that experience, you seem to have really centered around a lot of cardiac arrest Care Research. And it seems to be your passion in a lot of ways. Would you say that's true?

Dr. Robert Swor  3:23  
Yeah, I guess you don't work in the emergency department for very long and realize that we don't save a lot of lives in cardiac arrest. But what happens is people's lives are saved, they're saved in the field. So it has to happen prior to arrival in the department for people to generally there's exceptions. But generally, if somebody is going to get resuscitated, somebody's going to go home and pay taxes next year. It's because they got to defibrillated in a gym, they got bystander CPR, got a rapid ALS response, got defibrillated,  got drugs an airway, typically, if somebody comes home comes to the emergency department with a pulse, they've got about a 30% chance of leaving the hospital alive. Whereas if they come to the hospital with CPR in-progress without a pulse, they've got less than a 1% chance of survival. So I realized that fairly early on. And then if I was going to make an impact, or we're going to make an impact to the community in terms of saving lives for cardiac arrest, it's got to happen in the field. And there's a lot of literature from around the world and the country that just bears that out. So that's where it's kind of fun because EMS providers safe lives, its pretty straightforward.

Geoff Lassers  4:37  
How soon in your career, do you recognize the benefit of you know, we can say early intervention, but really utilizing your resources like you're saying EMS. You know, 1983 EMS wasn't exactly 100 year traditional organization at that point. So we still had a fairly new industry, and then you recognize the need for us to do more or at least to do well in the field to give the best chance of survival, how early in your career were you recognizing that was that in the early 80s? Or was it a few years down the road?

Dr. Robert Swor  5:06  
Actually, it's funny, because I worked for a year at Mark place Hospital in 1980. They had an als crew there that would work in the department. And they would be dispatched out to calls. In a word, those guys were great. They go bring a patient, bring it back, and you start the IV pump, help you manage the airways in the ED, and they talk to you for the next two hours. And they were very careful about, gee, if I did something wrong, I have to face Dr, Swor or whoever for the next couple hours or until this patient goes upstairs. And there was little that they did wrong. They asked lots of questions. I never realized that they were pioneers in EMS at the time. And they come up and they bring a textbook and say, well, it says here in Harrison's textbook for internal medicine, which was the classic text of the time, that this is how you treat pulmonary edema, you didn't do that. So right away, I learned that one, they save lives. And two, they were incredibly sharp and passionate about care. And that rubbed off on me. So that was actually when I started to realize the value of EMS. So long time.

Geoff Lassers  6:16  
It sounds like that's what attracted you towards combining the hospital and EMS to be a bit more interactive for the benefit of the patient.

Dr. Robert Swor  6:23  
Well you know, ems isn't just ambulances and providers, EMS is really emergency medical services. They're integrated systems of care that my vision of this has always been is that when you dial 911, you enter the health care system, the emergency care system. And so to the extent that that's seamless, and we provide care, and the surgeons know that now the cardiologists know that now the stroke providers know that now is that when everybody does better when this system works seamlessly from the time that somebody picks up a folder now grabs their cell phone until they leave the hospital. So yeah, it's a system of care. And everybody has a part in it. And I have a small part. So it makes it fun. It's been a good career pursuit.

Geoff Lassers  7:12  
Well, thank you for that. When we talk about improving cardiac arrest survival, we're talking about what you're talking about recognizing where there are deficiencies and where there's assets and, and creating a better system. It seems to be that there are growing repositories around the nation in the world to collect data related to cardiac arrest survival. One is CARES. And you seem to have an integration with CARES. Can you let everybody know what that acronym stands for? as well as give us an overview of what cares is and what they do?

Dr. Robert Swor  7:42  
Okay, CARES has been around since about 2003. Cares is a cardiac arrest registry to enhance survival. It was developed out of Emory University, they hooked up with the Center for Disease Control, which is also in Atlanta, got funding. And basically what it was was a database that could match up what happens in the field when what happened matches what happens in the hospital, so that we could get data on what happens in the field, and how does it impact ultimate survival. And over the last 20 years, it's grown to the point that now it covers about 30% of the population of the country, the director of the Health and Human Services has made a commitment that he wants a national cardiac arrest registry. And so they're developing funding for it. It's the bane of most EMS coordinators existence because they got to put the data into cares. And they have to chase down follow ups and chase down first response. And it seems like it's a lot of work, but you can't manage what you can't measure. So having the cardiac arrest database that includes both hospital and EMS elements and dispatch elements in a lot of places, is just vital to improve what we do.

Geoff Lassers  9:06  
You know, one of the lines I've always liked, I didn't come up with this. But one of the lines that somebody said to me once was how do you inspect what you expect. And what you're identifying is, is that we have now a system cares, which allows us as a data entry point to identify, this is what's supposed to happen. And now we can look at it in the field compared to what happened in hospital tied together strengths, weaknesses and lessons learned objectively and learn from those experiences.

Dr. Robert Swor  9:33  
That's 30,000 foot view of how the system works. And it's one way that the EMS system saves lives and be able to identify and document to the extent that we save lives in the community. You know, we save hundreds of lives every year and state of Michigan. It's invaluable to be able to document what we do and it's invaluable to know where the holes are in the system and how we can improve.

Geoff Lassers  9:58  
You mentioned that there is working involved with getting the data to transfer to care. So we look at that as work. And I think you and I both agree that the juice is worth the squeeze. So how does the data get to cares? In order for the cares people to categorize it?

Dr. Robert Swor  10:14  
Yeah, and the juice is worth the squeeze because it's not our Juice. But when we started this, it was all manual is that differently EMS coordinators for different agencies, we started out in 2005 actually doing it here at Beaumont with the care system, one first places in the state. And that was all done by hand. And there's a cares registry. It's a web based thing. It's de-identified once it's done so that it's HIPAA compliant. It's morphed into being able to be uploaded from ESO, so different image Tran different data elements. So some of those can upload the data directly into cares. Some of them can't. Some of them it comes and goes. But basically it has to start at the agency level where the data gets entered. It gets routed automatically to a coordinator at each hospital who will complete the data on:  Did the patient get hypothermia? Did the patient get cathed? was patient made a DNR? Did the patient survive to hospital admission? Did the patient survived to hospital discharge? And did the patient leave with a good neurologic outcome? Were they able to go back to work? Were they mildly injured? Were they're neurologically devastated? So all that stuff gets done on both sides of the hospital EMS divide, and creates a final record.

Geoff Lassers  11:41  
So that really ties together what I did in the field to what happened to the patient. And a lot of times I can't control what happens to the patient. And there's 50, 60 ,80 years of healthcare problems or just life, how it happens with people normally expire. But in those instances when we can do something, this would reveal the trends amongst hundreds thousands, if not even more cardiac arrest cases that are going to reveal the strengths, weaknesses and lessons learned of what we're supposed to do, would that be correct?

Dr. Robert Swor  12:08  
Yeah. You know, in Michigan, it's evolved such that we've got about 90% of state's population is covered by EMS agencies that provide data to cares. So we get to know that through the data, and each agency and each hospital gets a summary report once a year. And I'm amazed when I talk to people how often that report goes back to City Council's, hospital boards of directors, etc, etc. So people use that

Geoff Lassers  12:34  
people listening, if you've never seen your cares report for your agency as compared to your med control your county, your state and the nation, it's very interesting information. It is the stuff that dives into, was the patient released from the hospital neurologically intact? Or to what degree? And where is your agency in demographics compared to other agencies? And where they respond? And then how do you compare and what are they doing different than you if they're doing better?

Dr. Robert Swor  13:01  
Right? No question.

Geoff Lassers  13:03  
So that's what we do with the data. We learn from it. We collect it, we compare it and in Michigan, that's 90% of our agencies cover. So it's giving us an honest look at our state. And I'm sure we're not the only state doing that there's a lot of other very good states diving into probably more than 90% but there's this other organization called Save MI Heart. Can you compare contrast CARES to Save MI Heart?

Dr. Robert Swor  13:25  
Save MI Heart was developed by a group of medical control authorities and academic medical centers started out with University of Michigan, Beaumont,  Wayne State University, and now Henry Ford have sponsored the development of this organization whose job in 2013 was to double cardiac arrest survival in Michigan by 2020.Well in 2013 that sounded like such a great idea. And it still remains a good idea but we didn't get there by 2020. But our goal is to continuously improve cardiac arrest survival and mission. Organizations don't save lives or do things people save lives. So we hired Terry shields, who's the executive director and chairs coordinator have Save My Heart. So the foundation of Save MI Heart is the Cares registery. So the thing that Terry does is that she coordinates with all the EMS agencies and hospitals so she's got a fair amount of gray hair and on a big job to make sure all this gets done and gets the data for the state of Michigan, Michigan Cares so cares is foundational to Save My Heart. Any of you there have collected data for anything realize that it's such an exhausting process that you almost don't have time and energy to do anything with it by the time you've completed the process. So what happens is the Save MI Heart group tees that up for us and Terry, and she has other staff that work with your periodically collects that data, organizes the data generates the reports assures the data's clean. And does that and gets the data to users other reports. So what we've done with that is we've been able to get some money to support CPR training initiatives, hospital research projects, academic medical center research projects, initiatives and medical control authorities around the state, all of which that are intended to improve cardiac arrest survival, and probably can't do it without cares data. So we have a board of directors, we have an advisory committee, and there are subcommittees that address dispatch, community based care. So bystanders, CPR rates, post hospital care, and I think that's it. All of those groups focus on how do we improve rates of bystander CPR, bystander automatic fibrillation, dispatch, CPR provision, and lately, we've focused a little more energy and how do we get the hospitals to get more aggressive with patients that are recessive in the field, and improved survival in the hospital. So 9.8 million people in the state of Michigan, you can imagine it's a big initiative. And it all starts with people. And Terry and the group from say, my heart uses the cares data as the foundation to improve cardiac arrest survival.

Geoff Lassers  16:27  
That makes sense, you got Care's acting as a repository to say, here's the data no opinion, here's what it is, and then you're the group have saved my heart, and that's MI for Michigan, not M.Y. But Save MI Heart is taking that data and saying, okay, based on the conditions within Michigan and all of its agencies, what do we do, which is probably different than what you know, Ohio, or Kentucky or Indiana needs to do with it, because their numbers and conditions are different,

Dr. Robert Swor  16:54  
right. But interestingly enough, it's a it's a model for other states and a number of states have hit statewide initiatives to improve cardiac arrest survival, Michigan's the first time we've done it, as a consortium of medical centers and medical control authorities in Ohio actually develop their system similar to ours based on the same my heart initiative, but it's a good model works to greater or lesser degrees, it's like anything, if you had more money and more staff to do different things, we could focus more efforts on this. But we've developed a dispatch CPR course, we've developed an online dispatch CPR course, the city of Detroit was able to get some foundation money to develop focused training for bystanders and CPR in Michigan is that a couple of initiatives at Washington County and Livingston County, that are focused on what they call learning healthcare systems, health care systems, two that are based in the community to improve care. So lots going on, and say my heart supports all that sorts of great initiative.

Geoff Lassers  18:07  
Well, it sounds like cares is at least fueling these things to exist. And anybody working on the improvement of cardiac arrest, survival is cool in my book and is helping, it probably feels like you're beating against the wall sometimes when it comes to cardiac arrest, because at the end of the day, there's only so much you can do. And it's not exactly the easiest healthcare crisis to identify the trends and fix, because we have things that we expect, how they work, and then we have the data that shows how it actually worked. And that's a big reason why you're here today is to talk about some of this controversy in cardiac arrest. So data or cares provides us with an objective look at what is supposed to happen versus what actually happens. And sometimes looking at the data from an objective perspective can reveal controversy regarding the best quote unquote best treatment options for cardiac arrest patients. So bottom line, what we expect regarding how things work, or how well they work isn't always truth. So let's discuss some of these controversies that find our way into the discussions of BMS providers, and let's talk about the hard facts. First, let's start with airway and breathing. Advanced airways vers basic Airways, when I was coming up the MS and you were the physician, medical director of my paramedic school at the Oakland County Community College. In that time, it was made very clear to me by my instructors, and through my experience that et intubation was very important for me to learn how to do in a very, very high level, and we seem to be putting a lot of onus on at intubation during cardiac arrest back in those days nearly 20 years ago. Where is the data on et intubation for cardiac arrest patients versus maybe more basic or supraglottic airway devices?

Dr. Robert Swor  19:49  
So thanks for that and your observation and that's what I always remember is going to OCC and practicing paramedic students, the paramedic students always parroting that, and the tracheal intubation is the gold standard airway as the best airway, etc. Well, so I think what we've come to appreciate over the years is that the goal isn't to get a tube in the trachea so that we can blow it up. And that's, you know, our high five to do that the goal is to optimally oxygenate and ventilate a patient in a timely fashion, to control the airway to improve survival. So, somewhere along the way, we got focused on endotracheal intubation, and there were long pauses, you know, somebody would get off the chest, take 45 seconds, 60 seconds, etc, to place a tube in the trachea, and that didn't improve outcomes. So there was a lot observational data early in 2000s that identified that, well, maybe intubation was not only NOT the best airway, but maybe it was the way we practiced it in the field was something that adversely impacted patients survivals so people were off the chest, cardiac compressions weren't done, delays to de-fibrillation were done, etc, etc. So since probably about 2005, the Heart Association in the scientific literature has identified that we should be more focused on CAB, circulation, airway, breathing, versus airway, breathing, and circulation and airway intubation to undertake intubation wasn't the key priority of cardiac arrest. So that's the history behind it. And that's kind of where we all grew up with. So now the question is, what is the best airway? And I think I have to tell you that I'm not sure we know the best airway yet. And that what we know is that delays to intubation are bad intubation in the esophagus is bad.  supraglottic Airways, King Airways, combi tubes and esophageal operator airways back in the day, I-Gels etc, have a role in ventilating and oxygenated person during cardiac arrest? And what is the best way to do this? So that's all been the controversy probably over the last few years. 

Geoff Lassers  22:16  
So when I face this in the field, I go back to what you just said, the goal. What is the mission, what I'm dealing with the patient's airway, and what you're saying is it's optimal ventilation and oxygenation. It's not innovation. It's not a sad device. It's optimal. So to me that says, What is the patient: age, position, morbidities? What are all the things going on to select one of my tools, one of those tools once in a while might be ET intubation more often than not, I'm going to directly to OPA's and to airway devices, I-gels, King Airways, but I think it's really important for us to highlight Yes, the data is not conclusive on what is the best device. But what is conclusive is that optimal ventilation and oxygenation is something that's very important. But it also is prioritized after compressions in circulation.

Dr. Robert Swor  23:06  
Yeah, it's very interesting, because there's been so much interest in this, that probably two years ago, there were three large studies comparing, should we intubate? Or should we use a supraglottic airway? And I'll go through those in a little bit of detail. But also, the question is still isn't answered, there's one provocative study at Arizona a few years back, where they just put a non rebreather mask on patients in cardiac arrest, and they had a better outcome. But we started doing that in COVID, a little bit. But you know, that's the sort of study where you look at things when it happens, you know, after the fact. So nobody's actually randomized, no airway, versus airway in cardiac arrests. So while there's some data that suggests that that might be the best approach, and I'll talk about why in a bit, but mostly people have looked at what's the best airway. So there were three large studies, one in the US, one in England, and one in Paris, and they all looked at different things. The one in the US was done in 10 centers, what's called the rock Consortium, and they compared using the king airway to endotracheal intubation and looked at outcome of survival for out of hospital cardiac arrest, both survival, the discharge and survival with good neurologic outcomes. And so is about a three year study 10 big places. And what they look at is the strategy of on these days, we would just intubate, and on these days, we would just put a king airway and in the first airway, so what they found was that there was a mild but significant improvement in patients with King airways. So that was a little surprising and maybe counterintuitive to a lot of us. But there was a little bit of an improvement to King airway versus  endotracheal intubation. That gets complicated because an intubation day, you failed intubation, you put a king in, if you put a king in and you had it failed, then you pull it out and put it into tracheal tube. So the way you manage the statistics of this are complicated. But the bottom line was that King airways were mildly better. One of the observations that was surprising was is the intubation success rate. first pass intubation success rate for the tracheal intubation was 50% ...50%! So half the time people weren't successfully intubated,

Geoff Lassers  25:39  
that tell me that the Kings better just from that, because we're the king going in, it's probably a lot higher than 50%. So just on that, and just anecdotally feels like kings already better than me. No?

Dr. Robert Swor  25:50  
Right. But there's been so much literature over the last few years that I think paramedics have come to realize that, gee, I shouldn't spend a lot of time doing this. And I should quickly abort if I'm having trouble that's clearly been drummed into people's heads. So that study probably is going to drive practice in the US to a large degree. The results weren't overwhelming, but they were statistically significant. And they showed that patients that received supraglottic airways did better than an endotracheal tube. The airway 2 trial in England was amazing. It was four times the size of this us study. And they randomized patients to either by the paramedic, so a paramedic would intubate or use a I-Gel. And they randomize the paramedics as to who would give which device or which approach. And there was no difference in survival between I-gels, and endotracheal tubes in England.  It was four times the size of the US study, it covered 40% of the UK population. So huge study really well done. There were some certain subgroups that did better with just the I-Gel. But basically, the conclusion is, is there wasn't a difference between the two airways.

Geoff Lassers  27:09  
Is it possible to elucidate that their providers are more practiced with ET intubation than what we studied here?

Dr. Robert Swor  27:16  
I haven't seen data that compares what the training is of paramedics in the UK versus training in the US paramedics, I do think that they get paid better. And so there's more longevity. So you know, you're good paramedics don't grow up to go to med school, or go to nursing school, etc, etc. They stay in the system. So there is some systematic differences. But for this study, I don't think that was the key difference.

Geoff Lassers  27:42  
What about, you said on the other one was a 50% success rate with putting an ET was there? Did they measure the same thing for the 80 innovation in this case?

Dr. Robert Swor  27:50  
They did. And I don't recall what it was, but it was better. I do recall, it was better. So interesting study, very provocative, you know, was done just about the same time, I think actually was published in the same issue of JAMA, the journal American Medical Association, as the US partner airway trial, both of those come up within the US maybe as the Kings a little bit better than the ET tube. And the UK, I-gel was not different than in the US. So it gives you a bunch of different options as to what the circumstances are, and what's the best airway to use. So then the question, of course, is, should we not intubate at all? Should we just use bag valve mask ventilation? The French did a study that they compared intubation to bag valve mask ventilation, which is really interesting, is like, no, maybe we shouldn't intubate at all, maybe we should just bag because that's probably easier, right? Well, turns out that's not the case. The French use EMS physicians. Physicians that are not interns, physicians that are specifically focused on providing care in the field. And what would happen is, is that the patients would be randomized to either endotracheal intubation or bag valve mask ventilation, and they look to survival outcome. Now, as you can imagine, there aren't as many physicians that are providing care, as there are paramedics so there were fewer Doc's and their response times were longer EMS system is such that there's first responders that would all bag valve mask all of those patients. So all patients would get bagged initially, until arrival of the ALS crew ie: the physician crew, and then they either randomize them to intubate or bag valve mask. Interestingly enough, there wasn't a difference in survival. Interestingly enough, there were more complications in the bag valve mask group, especially aspiration. So not a surprise to anybody that's been on-scene and bagged a patient with a bunch of schmutz in their airway, and trying to figure out how to best manage and there were a certain percentage of patients that The rate of ventilation failure was high a little bit higher, not tremendously, but they were higher in the bag valve mask group. So, what you learned is we got to intubation because bag valve mask isn't so easy sometimes, a lot of times it's straightforward, simple, you can ventilate patients. A lot of times depending on the size of the patient, the circumstance, the location, bagging, the patient is just harder. So where we are with all this is that airways work. intubation isn't necessarily better than no intubation. And in fact, it may be better to intubate somebody or place an advanced airway than to just use bag valve mask ventilation. And there's different options for managing an airway, whether it's a supraglottic, king airway, or I-Gel. So that's pretty much where we are. And Geoff, you left a question out here as: has the rate of intubation increasing, decreasing or staying the same over the last 10 years? I haven't seen that data. But I'm pretty confident that most places are using supraglottic airways as their first pass airway. And that would be interesting to see what's the national trend or the state trend or even the county trends in terms of how many patients are intubated versus have supraglottic Airways.

Geoff Lassers  31:19  
that certainly would be interesting information, because it does feel in my practice, that we're pulling the ET kit out less and less, you know, we transition to the king visions, which allow us to be a little bit more accurate with our ET intubations with you know, it's a mini glidescope essentially. So that made it a lot easier. But then when we transition to COVID, we got away from all intubations. So I'm way out of practice with ET intubations, it's been a good solid six months.

Dr. Robert Swor  31:42  
Right. It'd be interesting to see the county's data. Does the county have data on this?

Geoff Lassers  31:48  
We're going to start pulling it because you're sparking up a lot of ideas. In my mind, I'm going to pull some data and see if we can also work with CARES to see if there's a national data we can pull as well.

Dr. Robert Swor  31:56  
Yeah, interesting stuff.

Geoff Lassers  31:58  
I do have one follow up question to your Paris fellows there. And I'm sure that the answer is yes. But I'm assuming they did utilize OPA's and or NPA's in the situations?

Dr. Robert Swor  32:06  
I would believe so. But I don't know that.

Geoff Lassers  32:09  
Okay, they didn't spell it out. But the standard of care typically, was would say that they did.

Dr. Robert Swor  32:14  
Exactly right.

Geoff Lassers  32:15  
All right. I do want to point out the I-gel versus the king airway. And I haven't used the I-gel a lot. I've recently been introduced to it in the last year, my agency is starting to look at them more and more. I like them a lot. What is your thought on the I-gel versus that King? In my opinion, don't tell King, but I think the I-gel is pretty cool.

Dr. Robert Swor  32:35  
Well, you know, it all boils down to money.

Geoff Lassers  32:38  
Oh-my-god. Really?! Are you sure?

Dr. Robert Swor  32:41  
No. And the places that I've heard used the I-Gel have been pleased with it. It's easier to blow up the seal around the larynx. And that's about it. It's seats in the airway pretty well. And they've done different versions of it to stabilize it. So yeah, the experience I have with the I-gel as it seems to work very nice.

Geoff Lassers  33:03  
Yeah, they look cool. They feel good, but it King airway, anybody working at King, we still like your stuff, too. Don't worry. But let's talk about ventilating. So no matter what we're utilizing, it's becoming more and more commonplace that our providers are understanding what proper ventilation looks like. my entire career has been a roller coaster ride of when to hyperventilate, then we ventilate too much we ventilate too little force versus pressure due..... So, what is the most obvious problem we're seeing with ventilating cardiac arrest patients. 

Dr. Robert Swor  33:36  
So it's interesting is that those of you that been in the field for a while now know that when you get on scene and there's somebody there, they're jacked, they're putting the bvm on, and they're nervous as heck. And they're bagging forcefully, and it's a, it's a matter of some honor as to tilting somebody's head back, putting the mask on, putting the airway and the bag on, and then crushing it against your thigh. I mean, that's what we used to see in the day. And the person that ventilates classically in cardiac arrest has been the least trained person, or the least experienced person, at least initially, until the airway gets placed. So that's been something that was observed. There was a study done in the early 2000s, where they noticed that some docs from Milwaukee were doing a cardiac arrest device trial, they would respond to the scene and they'd actually put in arterial lines in the field to measure blood pressure. They noticed that when they measured the ventilation rates, the patients that were ventilate, were getting ventilated, 24-30 times a minute, and the faster somebody was ventilated, the worst of survival rates of those patients. So they went back to the pig lab, actually, and they randomized the trial to a cardiac arrest out cardiac output based on ventilatory rate and they showed that the faster you ventilate somebody, the lower the cardiac output and the worst of survival, and that makes sense because basically, it's all about blood flow. And when you ventilate someone faster, you ventilate someone with a larger volume, you increase the pressure, the inter thoracic pressure in the chest, you decrease blood flow back to the heart, the decreased cardiac output in the next forward, and then obviously, decreasing cardiac output is a bad thing for resuscitating hearts and resuscitating brains. And that's true for anyone, a number of entities when somebody is in shock when somebody hypovolaemic you intubate them, you give them positive pressure ventilation, first thing that goes is their blood pressure drops. So the Heart Association standards have changed so that ventilatory rates are now 10-12. Ventilatory rates, you know, for kids are less. So less ventilation is better in terms of ventilatory rates for cardiac arrest. Now, that's easy to measure, you can measure how fast somebody ventilate, you can also do things to control them. We did the rescue trial A number of years ago, one of the more valuable parts of the rescue trial was it had low light that timed how fast you would ventilate, so then auditory rate is pretty easy to measure. And it's pretty easy to correct. What's harder to measure. And what's harder to correct, is ventilatory volume. And as we talked about, ventilatory volume is dependent on how geeked up the person is how well they're experienced they are etc. And so there's a group at Washington University, which is in St. Louis, who was able to use a simulator to measure ventilatory biomes. And that was helpful. So what they did is they started out with the hypothesis of, should we use adult bags? Or should we use kid bags to ventilate adults in cardiac arrest? What they did is they took a group of medics, and then they had them ventilate mannequins in a simulation lab, which was hooked up to a device that would measure ventilatory volume, and they identified the mannequin as your average 70 kilogram male. And they estimated that the right ventilatory volume. The standards, the right ventilatory volume is about 6-8 CC's per kilogram. So that's not a lot of volume. But 6x70 is 420 CC's, so between 420 CC's and 640 CC's and a bag valve mask an adult bvm is 750 to 1000 cc's i think is the right title volume. So what they did is they had the medics do a simulated CPR with an adult bag, and with a pediatric bag, not a infant, a pediatric bag. And they identified that adult mannequins that were ventilated with an adult bag were over ventilated in about 95% of the cases, pediatric bags, even over ventilated mannequins, and about 80% of the patients but also hardly ever under ventilated the patient with a pediatric bag. So in other words, a pediatric bag provides enough volume, probably still over ventilated patient, but doesn't under ventilate the patient in hardly 2% of the cases. So that's sort of provocative. It's like, should we be using a pediatric bag? Should we be teaching medics to just use two fingers for adult bag? Should the medics key role be to make sure whoever's at the head of the airway doesn't over ventilate the patient? I think the answer is yes to all that. So it's just somewhat provocative and goes back to the other literature on airway is that all these studies looked a lot at which device they were using, but they didn't look at how the patient was ventilated. So maybe the problem with all of our advanced Airways, ET tube or even supraglottic airway isn't that they're the wrong tube. It's just they allow medics and docs and providers to optimally over ventilate the patient. So the bottom line and this may be is that when way back in the day when there was parchment for EMS books, and Geoff was in a program that maybe that particular intubation was the optimal airway to best manage a patient's airway, maybe endotracheal intubation is a nice clear device that maximally allows us to over ventilate a patient. And that's why studies looking endotracheal intubation have worse outcomes. Maybe it's just easier to hyperventilate somebody and increase their ventilatory volume.

Geoff Lassers  39:39  
Less resistance! When I squeeze that bag and I got a direct shot with a nice clean tube. It's easy to squeeze the hell out of that bag.

Dr. Robert Swor  39:46  
Right! I mean, the way supraglottic airways are designed is you're going to fill up the hypopharynx and then it subsequently goes into the lungs.

Geoff Lassers  39:53  
Yeah, I got to overcome that little pocket to get it into the lungs. Right. So there's odd there's just more resistance. Physics imply there versus I have a nice rigid tube down inside a nice rigid tube that I'm filling up two big bags of air.

Dr. Robert Swor  39:56  
Right? So it's really provocative and really interesting that what we should do is that I think the answer to part one of this is the managing an airway is to keep patients oxygen, ventilate them adequately, make sure they don't aspirate, but not do that at the expense of getting good cardiac compression. And that ventilation needs to be the key thing that we're paying attention to smaller tidal volumes, slow rates 10 to 12, for an adult, and the person that's doing the ventilating needs to realize that they're not the Forgotten man or woman at the head of the table. They're the key driver of cardiac output for patients. So can we prove that? Probably not? That's all it's really difficult to figure out in the field, how much tidal volume.

Geoff Lassers  41:00  
 Yeah, totally, it seems to make total sense. But it also makes total sense that going to the physics of the inside of the chest cavity, the literal positive or negative pressure within that chest has so much to do with cardiac output, it's almost as important as how good you're forcing the chest because I could produce really good compressions. But if that chest cavity is full of a positive pressure, that balloon. (that's my two year old. Good. But when you have an, excuse me one second,)

lost my train of thought....

Dr. Robert Swor  41:42  
yeah, so, you're pushing it. If you've got positive pressure ventilation, you're pushing air up into the terminal juggler and down into the inferior vena cava. And you're squeezing it out of the chest, where it's not filling the heart, where it's not getting pushed forward by the next cardiac compression.

Geoff Lassers  42:00  
Yeah, we're like fighting each other, you got one guy pumping on the chest, forcing blood out, and then you got another guy filling up the bag inside the chest, almost slowing down the process. And what we're highlighting here is the tools that control the airway aren't necessarily the problem. It's the person squeezing the bag and controlling the air, which may be providing the problem. Right. So that brings us to episode our second episode that you and I are going to do in the next week or so which gets more into the compression side. But the link between the two is this little device I want to touch on before we go called an impedance threshold device. This is a really cool device, you talked about the timing lights on it, which are very beneficial. Every time it blinks. You squeeze the bag appropriately. But what it is, it's a one way valve that lets air escape so I can still ventilate the patient, it doesn't block it. But the chest will turn into a vacuum, which will increase the ability of the heart to suck blood in preload to create cardiac output, right. So give us your take on these itd's.

Dr. Robert Swor  43:04  
The long version is that we were involved in a study with five other centers that looked at the itd. And then a compression decompression device. I'm pretty familiar with the device and spent a little bit of time with it. And it's conceptually fascinating is that it makes sense. Keith Laurie, the guy that designed that invented this was talking to a respiratory therapist in the hospital and patients intubated, they're doing CPR, the respiratory therapist puts his thumb over the endotracheal tube. And you get this this inspiration, the sucking in sound that you would think that you would get if you're, you know, you're not letting air out, you're just putting a thumb over them to trachea. So it caused a negative intrathoracic pressure, which is what you do when you expand your chest, you get the same air more volume, so less pressure, so it's negative. So that improves venous return from the lower extremities from the rest of the body. So that's the concept behind that. It's also interesting is that there's some veins in the spinal canal that are decreased as well. So it sucks blood from the brain back into the lumbar plexus and decreases intracranial pressure. There's some theory that does that. So sounds like the right thing to do. The impedance threshold devices is a cool thing. It fits on a supraglottic airway or it fits in an endotracheal tube. There's a lot of literature in the lab that shows that it decreases intrathoracic pressure and it's associated with improved cardiac outcome. Unfortunately, in the largest study that was done nationally, wherever devices were randomized to rather the impedance threshold device or device that looked like the impedance threshold device that had a timing light, but didn't have the valve in it to cause success. And it didn't show any improvement in survival at all. So it's what the researchers call a beautiful hypothesis, slain by an ugly fact, is that just one big study. And like any study, there's limitations to it, the time to get the device sign, etc, etc. So in our hands in the rescue trial that we did, as part of a system of care, you know, using the rescue pod and the pump, the itd improves survival, there was a slight but real improved outcome in patients that got both devices. But in the large trial, the I can't remember the name of the specific trial, that the trial while the rescue trial was, was the standard. The Rock prime study where they looked at the itd versus the sham   ITD didn't show an improved outcome. So a lot of places are still using the ITD. But a lot of places said a, you know, this is 80 bucks a pop, we're not going to pay for this in the setting of cardiac arrest. So the itd is a great concept, it works well in the lab. They're using something like it for low flow states like patients and hypovolaemic shock, because it increases venous return on output. But it isn't what I would call standard of care, the treatment of hospital cardiac arrest.

Geoff Lassers  46:27  
Yeah, I totally agree with you. It doesn't seem to be coming the standard of care. But man, when I heard about it, and I understood the simple science behind it, it just made sense to me. And I was actually surprised that the numbers weren't more impactful. But you're saying there is a real, measurable difference in certain situations. And maybe over time, with the increased use of it increased availability of it, we may be able to study the benefits of it and apply those to other situations as well.

Dr. Robert Swor  46:53  
Yeah. And the rock prime study was a big network of our How to cardiac arrest research sites is the same group that did the ET versus King airway study. So it was big, nationally funded NIH multicenter network that was designed to do stuff, I don't think you're going to see another big study like that, anytime soon. So you're stuck with there is an overwhelming data proving benefit. And there's some smaller studies or other writer studies, and conceptually seems to make sense that it would work, right? 

Geoff Lassers  47:26  
Totally. It's just, well you look at it, and then you literally can take a container, stick a balloon inside of it, turn it into a vacuum inside of there, and you watch it expand. It's like there's preload, it doesn't make sense that it doesn't work to me. So there's obviously things we still need to learn.

Dr. Robert Swor  47:43  
Well, you know, there's a device and they're not paying attention to other things they need to be doing, if they're slow and getting it if it gets clogged all of the real life, things that get in the way of trying any new intervention. But it's conceptually a it's a cool thing. It's conceptually things that a number of different communities continue to use and results in physiologically makes sense.

Geoff Lassers  48:13  
totally makes sense. And I think it's a great topic to pick back up on in our next episode, we transition to the use of maybe that with mechanical CPR, active compression, decompression of CPR and compressions in general, we'll get into circulation. In the next episode, we wanted to focus more on airway breathing ventilation in this one, and we'll continue on with cardiac arrest controversies with Dr. Swor in another episode coming up soon, Dr. Swor Do you have any closing comments for us today?

Dr. Robert Swor  48:39  
sir, thanks for the opportunity to do this. It's interesting how far we've evolved and how far we still have to go with cardiac arrest care.

Geoff Lassers  48:48  
Absolutely. And no matter what we learn, I think we're gonna learn something new. And we'll just find another mountain to climb. And I think that's kind of the point. Yes. All right, sir. You have a great day.

Dr. Robert Swor  48:57  
Nice talk with Geoff, Take care.

Geoff Lassers  48:59  
everybody. See ya. That is all for the show today, everybody and thank you very much to Dr. Robert tour for joining us today. He'll be back everyone. Remember we have a part two where we're going to get into Circulation, Compressions and Blood flow and the related data brought to you by Dr. Swor.

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