All right. So once again, my name is Dr. Michelle Waters. I'm a medical officer with the National Transportation Safety Board, and today I'm going to discuss how NTSB evaluates medical impairment in our investigations. I have nothing to disclose. However, I did provide for today's presentation three learning objectives. First, of course, as mentioned, I'm going to tell you the approach that NTSB does take in evaluating the medical aspects of our transportation-related accidents, and in doing so, you'll recognize how medical accidents or medical conditions and the factors contribute to our discussion on accident causation. And finally, by some of our case examples that we're going to present today, you'll learn some medical conditions that we look at that may inversely impact human performance for safety-sensitive positions. So we are the NTSB. We are an independent federal agency, so we are very distinct from the Department of Transportation. We get our funding and report directly to Congress. So we're charged by Congress for investigating every civil aviation accident in the United States, as well as significant accidents that occur in all the other transportation modes, such as railway, highway, marine, and pipeline. And in doing that, we determine the probable cause of the accident. So we gather facts, we look at conditions and the other circumstances around the accident to make this determination, and in doing so, we sometimes recognize what safety issues exist, and then we make safety recommendations to the appropriate groups to prevent future accidents. In addition, we may also carry out special studies concerning some transportation safety, with our overall mission being to make transportation safer by advocating safety improvements and by conducting independent accident investigation. And as you'll see, we have both statutory and regulatory authority to complete our mission. So the agency has about 400 employees, of which there are two medical officers currently. I have a background in occupational and environmental medicine. The other medical officer has a background in emergency medicine. Some of you may have worked with Dr. Mary Pat McKay. She retired last September. And as an aside, our Human Resource Department has promised and assured us that the position announcement for the other medical officer should be made soon on USAJOBS. And if you have any questions about the position, please take the opportunity at this conference and otherwise to talk to me about it. So part of our job is to conduct the medical investigations for the medical aspect of the investigation. And we work doing this, we work in tandem with the other investigators. So our primary cases involve some aspect of human performance, although we do provide consultation on both survival factors issues and the operational issues that involve impairment. We also participate in activities related to the medical aspects of transportation research, policy, and outreach. So with our investigations for the medical aspects, we're always asked the question, did a medical condition, its treatment, or use or exposure to substances lead to impairment or incapacitation that contributed to the accident? And as you'll see from our case examples, we don't do this in isolation. We always work with the investigators and take into account operational, mechanical, and other issues. So what is medical impairment? So as an aside, I presented on the toxicology aspects of our medical evaluations in Utah last year. So some of these, there's overlap because the approach really doesn't change in some respects, whether we're looking at medical conditions or toxicology issues. But for the purposes, I'm sure maybe some of you worked in my presentation at Utah. We'll continue. So let's step back and look at what we meant by impairment. So I'm sure many of you have to deal with impairment and disability in your jobs. However, for us, the medical offers, we view impairment as any loss or abnormality of psychological, physiological, or anatomical structure or function. So the impairment can be from a medical condition or from the substance that may be used to treat that. And those things might alter the person's judgment and their thinking process. It could make them take more risks. They also might diminish their reaction time or impact some aspect of coordination that's needed. Also, while you have sort of longstanding issues related to impairment or disability, for our evaluation, we really focus on the period leading up to the accident. So now when we evaluate impairment, we also look at a range. What is a peak performance? And that's a peak performance for the person who has their level of skills and experience versus the other end where we have incapacitation, with everything in between being impairment. So in assessing medical impairment, we answer three questions. Okay. Probably the easiest in some respects. Did an increased risk for medical impairment exist? Did medical impairment occur? And finally, did medical impairment, even all those things were okay, did it actually contribute to the accident? And bear in mind, for any of these, we may have can't be determined. And also, particularly for the last one, all of that is put in the framework of the operational, you know, the contextually in the operational and other issues related to the accident. So on our left-hand side of the screen, you'll see things that most likely you've always viewed as like, oh yeah, medical records. Of course, we're going to gather all that information. And in this presentation, I'm going to go through those records and how we use them. However, bear in mind that for any given accident, we're using multiple records. We might not necessarily need to collect all of those records, but we'll usually have at least three or four of them that we look at in terms of our evaluation as appropriate. Also, it's a bit of an iterative process. Some of it's in terms of how we receive it. So our tax results usually come back within four to six weeks from various sources for after post-accident testing. And when you look at those numbers, it's like, hey, we have a hit for fentanyl or ketamine. And it's like, hey, was that taken recreationally, or was that part of treatment as if how the post-accident treatments would have nothing to do with the accident? So in those cases, we would gather, for example, based on the toxicology, we'd go and get the post-accident medical records. All right. Now, of course, I've kept saying, hey, we work with all these operational, mechanical, and other aspects. So we had always, we talked, get information from our investigators. We have our research and engineering group have done all the analysis on the voice recorders. And we have different photos. And we've downloaded all these things to actually, again, we're putting everything in that context to make that final determination on causation. So on the bottom here, not meant to see it at all. This is like a little bonus case. So this is an image of like both throttle and speed during the last short duration of this accident. And this was a operator, a remote control operator, who was switching cards inside a warehouse. And he, after, continued on, went past the end of track bumper post and went through a wall. And afterwards, he survived. And he was saying, hey, after the first four car count, I don't remember anything. I think I blacked out. And again, oops, wrong one. Okay. On this top line, you'll notice that we have an event recorder from the engine. And you see that it represents the oscillating inputs and pretty erratic of the throttle. And the actions are consistent with seizure activity, which actually this remote control operator had. And that was part of the causation. But to go to our reports and our records, we're going to start at the top of the list with the autopsy reports and the medical device recordings. So as mentioned, NTSB only does things through statutory and regulatory authority. And one of those is to obtain autopsies. So we have the right to get any autopsy that's wrong. However, we also have the right to order an autopsy on an operator. And you're like, well, why would you need to do that? Wouldn't that automatically be done? And it's like, no, because, you know, the airplane fell out of the sky. The pilot died of blunt force trauma. It was an accident. And the medical examiner or coroner might say, there's no need for me to go further. Why am I going to spend this money doing this when it's pretty obvious, you know, the guy's in pieces. However, we are looking at the cause of the accident, not the cause of death. And so that's why we do have that ability to order them if they are sort of like putting up a front saying, ah, we don't need to do this. Okay. So the autopsy itself is, you know, we're just trying to determine the cause, the mechanism, the manner of death. And we also use it to obtain tax specimens, other physical evidence. And I mentioned, we sometimes do survival factors. So sometimes the way they report the injuries is also very helpful. So cause of death tends to run the gamut in terms of the accident, you know, blunt force trauma, multiple blunt force trauma, multiple blunt force injuries. Sometimes you had it with thermal injuries added to the fire. However, for categorization, manner of death, there's only five listed here. And for NTSB purposes, if we know it's a homicide or a suicide, we do not perform an investigation. However, we may be able to assist law enforcement or local law enforcement, as well as the FBI in terms of some of those issues. So yes, ideally we want this whole autopsy done. In reality, all these components are not performed. Some of them are for very practical reasons. Some of our accidents, there's multiple body bags, the brain's evulsed. There's all sorts of issues that prevent them from doing this whole autopsy. The quality also differs between the medical examiner's offices and how quick and how fast and how cooperative they are. And some people just have a different level of detail. So on some reports, we'll have that, you know, the left ventricular hypertrophy and the ventricle size was 1.6 millimeters. The other one, it says, looks enlarged. End of story. So there's a little different things that you can extract from these reports. But speaking of the reports, what we actually focus on are, if you see on my right-hand pictures, essentially we're looking at primarily for the brain, cardiovascular system, and respiratory system. And the reason being is that we're looking for something that might influence either impairment or incapacitation. And those are the systems that are most likely to be incurred with. Now, we also request that any kind of indwelling devices be interrogated. And that's valuable to us because a pacemaker or a loop recorder or some other devices can actually document the electrical activity occurring, which is not going to be identified on an autopsy. I mean, the guy is dead. There is no electrical activity. Other indwelling devices may suggest a medical condition. For example, I had a helicopter pilot who had crashed. And while not many things were available to him in terms of organs, there was parts of a deep brain stimulator that he had implanted. And the head wound up having a history of Parkinsonism. And as you might suspect, having Parkinsonism and trying to operate a helicopter is not compatible. Okay. So let's start our first case. So this is a glider. This picture, however, is not the accident glider. It's just a picture of a similar kind of glider. So the glider is released from the tow plane. And witnesses are observing him going, swooping, making curves. Very nice. Suddenly, though, they see him making a very, what they describe as a zoom up. And then he lands up flipping over and making a 60-degree downward plunge into the earth. It's a beautiful day. Great day for flying. We couldn't find anything mechanically wrong with the aircraft. And the pilot, who was fatally injured, was an 82-year-old male. And he had actually, on various other airplanes, he had 15,000 hours of flight time. He did have an expired certificate. We're going to talk about certificates next. But really, you do not, it is not required for glider operations. So his last exam was about 10 years prior. And at that time, he had dutifully recorded, hey, I've got coronary artery disease. I've had an MI. I've had a four-vessel cabbage. And even at that time, despite that, he was given an FAA medical, third-class medical certificate with a special issuance. So they reviewed his material. It's stable. You know, again, he had an increased, shortened interval for his next exam. But nonetheless, he had, even 10 years ago, having reported that, he was able to fly. And I only mention that in part because sometimes you worry about pilots or other operators not reporting things because they're like, I don't want them taking away my medical certificate or learning about this, so I won't tell you, share with you my disease process. But there are mechanisms in place, even, you know, to show that everything's stable. And that's the idea, is like, when you're measuring risk. At any rate, we also had some current medical records that show he had had a pacemaker, and it was operating fine in 2011. So, what's our autopsy show? Okay, cause of death, multiple blood force injuries, as you would expect from crashing from many feet into the ground. The medical examiner also mentioned that he did have some cardiac disease that might be contributory, and part of that was based on the presence of the pacemaker and some findings of coronary arterial atherosclerosis. But we had some other major injury findings. One of them was transection of the C1, as well as many things that you would expect there to be catastrophic blood loss, including the transection of the aorta, lacerations of the heart and lungs. But, despite that, he had a minimal amount of blood in his chest cavity. So, the pacemaker was sent out for interrogation, and as you, this is just an example, not from this case, but what showed was ventricular tachycardia. And there was some issues involved with the time stamping of this, because, as it turns out, with discussions with the manufacturers, like, the time stamp isn't set on a universal clock, you know, some atomic clock somewhere in, you know, God knows where. It is actually very dependent upon the office in terms of how they're downloading when they set the clock. So, we had like a little bit of disconnect between, we know we have this ventricular tachycardia, but for us, when we're looking at what happened, we have a loss of control accident. We have severe injury without any significant bleeding. We have evidence of a terminal arrhythmia. And so, our conclusion was that, in this case, the accident was caused by either impairment or incapacitation by the episode of ventricular tachycardia. So, some key points in terms of our autopsy evidence. I did point out that the quality is very different between something, you know, making, having someone realize that we're looking for the cause of death as opposed to just the cause of, I mean, the cause of the accident as opposed to the cause of death. But it does really provide some valuable information, particularly for us, some of the interrogation such. We do have limitations. Again, sometimes, again, because of the state of the body, you cannot do a good autopsy regardless. And some of those other activities, like the stroke, seizure, myocardial infarction, or dysrhythmia, either you're not going to have any evidence of electrical activity unless you end up having a pacemaker or a loop recorder, or any kind of, it's such an acute event that you may not have that time to have some kind of histological evidence that showed that, you know, like you don't have the time to cells to try to do the repair in terms of fibroblasts and everything else. So you might not be able to detect some of the other things. Again, even like stroke and stuff, damage to the brain, it's like how do you distinguish between some of our hemorrhaging versus post-accident versus pre-accident. So again, always taking, having to view the whole big picture in terms of what also you know about the accident. So our next one is probably a little bit nearer and dearer to some of you in terms of medical certification files and occupational medical files that we might receive. Once again, always operating under context of statutory and regulatory authority. In this case, we have regulatory authority to form a party system. So what's throwing this party? So for all of our accidents, we will invite various people who have had either it's their employee, it's some kind of activity, or it's some product that is related to the accident. And that might be something like the engine maker. So we're inviting Rolls-Royce. It's the Rolls-Royce engine. We're inviting Rolls-Royce to participate because we want to know if perhaps it's an engine value that caused the accident. It might be also if there's a labor union involved. Brotherhood of railroad people are often if there's a railroad accident, for example. And some of the caveats for the parties though is they have to have some people present that have the technical expertise in order to assist with the evaluation. These are not just bystanders to our accident investigation to get a heads up. And as an aside, we can kick out people that are bad party members. So we can throw people out of our party. And those happen if we're supposed to keep our investigation while it's being evaluated without mentioning to the press and the public. So we have had cases where some of our party members decide to talk too much about what happened prior to our results coming out. And so they were no longer party members. The other caveat is that the party representative cannot be in a legal position or have some kind of claim or an insurer to the event. So that's sort of to eliminate some bias that might be imposed by having those skills brought to the table. You'll also see the middle bullet is also part of our party, because we're doing transportation ads, are the different regulatory agencies, DOT agencies. Mentioned US Coast Guard is a slightly different arrangement, because they actually, while we have a party, the US Coast Guard is actually the lead to any marine investigation. And we're assisting, with the exception of a few cases. So as long as we're talking about the medical certification from the regulatory agency, I sort of put together this chart in some key. There's many other differences and similarities between the different agencies here. I don't list FTA. FTA essentially would have a lot of nos on this list, just a different process in terms of how they do their certification. So I imagine most of you are probably most familiar with the FMCSA part of this chart, the second one from the right. And one of the differences is that for the health care providers who perform those driver's license certification exams, they don't have to be able to prescribe medications. So you really have expanded the pool of people who are doing those exams. And we have made recommendations for that to counter that in terms of how much training or education might be needed in order to perform that. As well as, if you look at the third one down, is unfortunately the person performing those exams do not have access to previous exams, including one that might have happened three months ago when the guy was deferred. And we feel that is a gap and have commented on that as well, as we think that's important in terms of having that information beforehand. Now, you'll notice the Coast Guard also doesn't have trained people. And people can't see that. So they just have a regular person goes to their physician and they might let, hey, how much does this person know about a merchant mariner? The difference between the two, however, is that the US Coast Guard evaluates every single applicant for a merchant mariner applicant. And so you can bypass some of the other issues because they're making the final call on the merchant mariner certification. FRA, as you know, falls under regulations that are hundreds years old. And so really, they're engineers and conductors. All that's required of them is every three years they have their vision and hearing tested. Of course, for both railroad companies as well as any of the other companies involved with this, they could have more stringent medical or more comprehensive requirements for their employees. So our case happened in Baltimore. And it involved a school bus driver. Fortunately, it was like at 630 in the morning, hadn't picked up any students. There was a teacher aide on the bus as well. So this driver is zipping along on this road. And he has involved in two accidents. The first happens here. And at 57 miles per hour in a 30 mile per hour zone, he rear ends a Ford Mustang, forcing that Mustang forward about 75 feet, having him smash into both a curb and a brick wall, stopping that vehicle. That driver had a minor injury. And the only plus on that side is it slowed the vehicle down somewhat. So he's now going 47 miles per hour. After accident interviews, the teacher aide said, well, I asked him what he was doing, like what happened, and he didn't respond to me. Anyway, the driver or the, oh, sorry. I will manage this eventually. The driver proceeds along and unfortunately crosses over from the eastbound lane to the westbound lane of traffic and smashes into a Maryland Transit Administration bus that had both 13 passengers and the driver. The 33-year-old driver is killed in the crash. Four of the passengers are killed. Five of them are seriously injured. And four of them have minor injuries. And from this accident, the bus driver is killed. And the teacher aide has a minor injury. So the driver is 67 years old. And he has high blood pressure. He has diabetes. He has hep C. He also has a childhood history of epilepsy. And he has been recently and has been prescribed carbamazepine. What is noted in the medical records that we have is the doctor said, hey, this guy is rarely compliant with his medications. And to demonstrate that, you find our bottom line that we had sent some samples to the FAA toxicology lab is that his carbamazepine is at about two milligrams per liter, which is half the lower end of therapeutic of 4 to 11 for that drug. So this is a discussion on medical certification files. So as you probably have a lot of familiarity is, the bus driver fills out this top portion saying, hey, what kind of conditions do you have? You got high blood pressure. Do you got diabetes? Everything else. So we had records from a few years back. So starting February 2014, it's like, hey, I don't have any problems. No meds, no medical conditions. But the examiner says, hey, your blood pressure is a little elevated. I'm going to issue a three-year certificate. Come back with this form signed that your blood pressure is controlled and the blood pressure isn't impairing your ability to drive. He comes back. Actually, it's not that it matters. It's a nurse practitioner who comes back. Sorry, that should be a slash, not a dot between the 132 over an 89. But the practitioner says, hey, it's 132 over 9. Sure, he's good. This high blood pressure isn't impairing. And so he's given a one-year certificate. That nurse practitioner does not have any affiliation with his normal primary care doctor, as an aside. Comes back next year. Blood pressure OK, but this time he has elevated urine in his urine dip. OK, come have three-month certificate, come back. Now again, the man's saying no medical conditions, no medications. Doesn't come back right away. Comes back in August. And this time he had gone to his primary care doctor. The primary care doctor looks at the form, says, hey, he's got a hemoglobin A1C of 7.7, not too bad. Yes, he has high blood pressure and diabetes, doesn't mention epilepsy. And this is a treating physician for epilepsy. But that's not going to be impairing for his driving. And you know what? He also adds a comment, is I think the driver was under the false assumption that because he was being treated, he didn't have to report it. So anyway, he's issued a one-year certificate. Again, that commercial medical examiner had no way of knowing, at this point, that he has epilepsy. June happens. Hey, don't have any medications, no medical condition. This time he does have an elevated blood pressure again, but it's like, eh, we know you have, you know, fine. I'll just give you a one-year certificate. And this is actually a few months just before the accident. So as I said, we do a lot of things sort of iterative and in combination. So we also had some medical records we obtained over time from other sources. And we also, from other records, from driver's license records, in the last five years, a guy had 12 accidents in either the bus or in his car. In October, he landed up in a bus, and the passenger actually helped trying to steer the bus out of the way because the bus driver blacked out for five to 10 minutes. The driver was confused when EMS arrived. They take him to the hospital. Later, he tries to file workers' comp, but it's denied because he doesn't want to provide any information to workers' comp. October, these are all the ones I have listed are all the bus-related accidents. He lands up having a seizures unconsciousness. By the time EMS arrives, he's doing better. He refuses treatment. June, in front of his supervisor, he experiences a seizure. So he's not actually in an accident, but he's in front of a seizure. And he experienced what she felt was seizure-like activity. EMS is called. They bring him his glucose is high. They bring him to the hospital. The hospital notes say he's a school bus driver. Anyway, they release him. Now we have, and that was also June, of course, if you recall, was when he also had his CDL medical exam. So this next one is in October, eight days before the fatal crash. So once again, in front of co-workers, he exhibits some seizure-like activity. And they call EMS. EMS comes, and he's sort of a little belligerent. Like, no, I don't want this. Let's his pulse be taken. But denies having any kind of seizure, even though these other people witnessed things, and never transported to the hospital. So all of you, I'm hoping, are saying, how does this happen, where this guy is still driving the bus? Because you know from federal regulations that this is a disqualifying condition for a commercial driver's license. Also, and again, in terms of the actual medical examiner, they had no knowledge of this. For Maryland, of course, you also had from their MVA. It's like the driver, the onus was on the driver to have told them that he has epilepsy, which he also did not tell them. And finally, as far as the physicians go, they are allowed, so it's like, legally, you're not going to get in trouble if you do this. But they are not required to record any kind of lapse of consciousness. So from our safety side, as you might guess, we did find the cause of this accident related to his seizure activity. But we also called out both the bus company and the city public schools. Recall, you have supervisors, you have co-workers, you have all these people who knew this guy was having seizure activities, and did not report it, and did not stop him from performing those activities. And from that, we did make recommendations, one to FMCSA, because that form is so limited in terms of saying, hey, report high blood pressure. Tell us about this. As opposed to saying, what are the medications are the guy using? And having the physician put in a more holistic approach of saying, is this guy, is there some potential for impairment that we should know about before we issue a CDL? Also, there were recommendations to both the Maryland Department of Education, some bus driver associations making them, working on training and awareness for the people. It's like, hey, you should really inform people if you know a driver that has these issues. So our key points, as I said from the chart, you saw there's a difference in terms of the qualifications, how much oversight you see with them. There's always a concern about how comprehensive the exam is, whether the applicant has ability to doctor shop, and that has to do with how well you can actually see previous results. Again, a recommendation we have been made is that, for FMCSA, is that medical examiners should be able to see if that the person is on a deferral or has had some point been refused the application. But unfortunately, all of them rely on self-reporting, which is, you know, the burden is on that person. And if they choose not to, that's really difficult to get around that. And again, pointing out the limits of the supplemental invocation. So next, medical records. We've got a slew of them all grouped together, and these all fall into personal medical records. Once again, what's our ability to get these? And we have subpoena authority, so we can obtain and inspect any record that we feel is related to the accident, including the medical records and as well as obtaining specimens. And so for the record part, these are mostly looking at various hospital, clinic notes, pharmacy records, those things. Now, you might ask, and under HIPAA, NTSB is considered a public health authority. So under that, any kind of health entity must provide us, when we subpoena, they can provide us those records without getting patient authorization or their approval. However, in doing that, we are actually pretty cognizant of we try to really focus the number of records we ask of someone or direct what kind of records we want to receive from the entity. And we do have protocols in place in terms of the transmission, the storage, and the retrieval to prevent anyone obtaining them outside of that. And as far as disclosure to our party members and to the public for the docking, those all govern what we can post by the Privacy Act. And we always, as I said, try to weigh both the individual privacy interests with terms of public health. So to illustrate some of our medical records, I've got a railroad accident for you. So this involves a sort of a shoving operation at a industrial facility. So we arrived a little bit after 3 in the afternoon, nice enough day, clear enough day. And the engineer and conductor, they were going to, as I said, remove some of the cars onto this track. So they had conversed about it. So the conductor is riding. He gets off the platform, sets it to the derailing to allow the one train track to go in. He gets back on the platform, continues down the way, puts the switch and allow to the switching movement, goes again, moves to the walks over, sets another switch to set the rest of the movement, and then is standing aside the train as it's moving along, communicating with the engineer as he's proceeding at about nine miles per hour. And they're supposed to be removing so many cars. So it's supposed to be a total of like 20. So he's counting down. And they're talking back and forth. And about the 10th car, the conductor starts communicating with the engineer. So he does what is appropriate. He puts on the brake. But as I said, this locomotive is going about nine miles per hour. And when they go out to inspect, the guy has fallen to the side of the track and has been fatally injured. So when we look at the conductor, he is an experienced man, got 20 years of experience. And from his medical records, you're like, he's got high pitch hearing loss, but nothing particularly. And he had a work-related knee injury in 2016. But pretty much nothing terribly remarkable. We look at his autopsies. They mentioned he's obese. He's got cardiomegaly, some atherosclerosis. The post-accident FRA texting, nothing. From our FAA taxing, which is a little more extensive, they're like, yeah, he's taking some blood pressure meds. Same thing with the coroner's office. So still not too remarkable. But because of there's some conversations with, we have interviews also that we have. And some of his co-workers are like, yeah, great guy. He had a lot of personal family issues, financial issues. Oh, and he always was complaining about his feet hurting and his boots don't fit. Anyway, so for many other reasons, as well as just thoroughness, we did wind up getting personal medical records for him. So a little longer list. So yes, he's obese. Big guy. So BMI of 38, 277 pounds. Talked about the high blood pressure, has diabetes. Also has peripheral neuropathy. He's had a history of foot ulcers. Right now, this last record was like a month before the accident. Prior to that, he was there like a year visit prior to that. Anyway, so on his previous one, he needed treatment for cellulitis and had gone to some other podiatrists and specialists to treat that. But at this visit, it's like, hey, you got some calluses, but your feet look pretty good. No ulcers or abscesses. Yeah, we have your coronary arteries medically managed. And yes, he has that history. He had the knee injury, but he also has pain and osteoarthritis there. He had some steroid injections sometimes. And then he was taking on his own really high-dose aspirin. And the physician said, no, no, don't do the high-dose aspirin. Do high-dose Tylenol. So switched him to that. The Patient Health Questionnaire, that survey, it's a psych survey, says, hey, you've got mild depression. Said, hey, sometimes I'm pretty tired. I fall asleep. I have difficulty concentrating. And again, he did have some personal family issues and financial issues that he was concerned about. Refused to have any kind of counseling or medications. And on our bottom one is that he has a diagnosis of nocturnal hypoxemia. So he did have an overnight pulse ox study a few years prior, and that showed that his oxidation stats were fairly low for a good percentage of the time during his sleep. Refused oxygen, refused a more advanced sleep study, and said he was never going to use a CPAP machine. Actually, this visit, like one month before, he was finally conceding, like, yeah, maybe I'll have a prescription for oxygen. But no, I'm not going to do a sleep study or use CPAP. All right. But I did say that, you know, we look beyond medical. So if you just looked at that, you're like, oh my god, this guy's a train wreck. However, we look at all other aspects. And so this is the track. So this is one of our investigators. The middle photo will actually, both the photos are one of our investigators looking at the train track. And what you should notice is, like, it's pretty darn narrow, and it's pretty steep. So the Missouri Department of Transportation went out there and said, hey, you don't meet the regulations in terms of how wide this should be and what the grade should be. Got 30 days to fix it. And as you can see, they did fix it. So let's see what we have here. So we have these medical records and interviews that said, this guy has difficulty walking. He has an increased likelihood of falls. He has, you know, other things that might impact his psychomotor performance. We know he has, like, personal issues. Is that distracting? But he's an experienced guy. He performs his job on a regular basis, day in, day out. He does this. And, like, that track would pretty be difficult for even a fit person to do. So from the medical side, we sort of had that box of can't be determined. Like, did this really play a part? Didn't it play a part? And so it's not included in our final conclusion. So our key points, yes, obviously you've seen. They are helpful, though obviously not the deciding factor in terms of looking at contributing aspects to the accident. We also, we do look at undertreatment. Actually, the seizure activity was probably a better example for undertreatment and what might have happened, or change of medications, or things like that. And of note, oh, yeah, we also think of, like, is the treatment worse? Or is the drug that's used to treat it worse? We look at which is more impairing. This man did not actually go to see a psychiatrist. But I will just tell you that, in general, even for a deceased person that has no privacy rights, by the way, the whole Privacy Act does not include dead people. It's really very difficult to obtain, to try to evaluate if there's something that might be occurring from a psychiatric standpoint. So our final record to look at is tax results. Again, if you were in Utah, I had a whole long presentation of interaction of impairment, but what we're going to talk today is how does that interact with our medical conditions. Do we have subpoena authority? Yes, as mentioned before. So we can obtain any specimen. We can obtain the tax reports from FRA taxing, other DOT testing, as well as other people like law enforcement might do it. But we also can obtain leftover specimens. Not a split specimen, but leftover from sample A, or from the hospital, like the first draw subs from the hospital, or from law enforcement. The caveat is that we, and we get results from autopsies, samples from autopsies, but the caveat is that we cannot ask for an additional sample. So if there just doesn't happen to be enough blood, we don't get that additional testing. And who do we do this additional testing with? Well, we have an agreement with FAA, their Civil Aerospace Medical Institute, their Forensic Toxicology Lab. They can test for over 1,000 substances. So when they're testing for amlodipine, not necessarily on the DOT list of substances you're going to pick up. So they test for about 1,000 substances, and we use them for all sorts of modes. And I'm digressing a little bit, this is odd how that one skewed, to a safety study that we did. And again, I presented a little bit on this and the other one. So this is co-authored by our former medical officer, Dr. McKay, and our chief data scientist. And this was a five-year study. It was an update to a 21-year period study that was looking at drug use amongst fatally injured pilots. And we were looking at the prevalence, but not whether it was impairment, of over-the-counter prescription and other illicit drugs in these aviation accidents. So we divided all the drugs we had, like this 1,000, and again, for this purpose from 2008 to the 2017, they're really directly comparable because the cut-offs were the same that FAA used, as well as the number of drugs they were testing was the same. And we said, are they potentially impairing or not? But for our purposes for this talk, we're going to look at the potentially impairing conditions. So there is overlap. Obviously some of the drugs, carbamazepine, has some potential for impairment, as well as epilepsy itself. But there's other drugs that just are indicative of a medical condition. And those typically fall into pain, arrhythmia, control, neurologic and psychological psychiatric conditions. So you'll see our green. Actually all over time, all the drugs, we have had an increasing number of drugs found in our pilots, our fatally injured pilots. And right now, it's about 15% of them had some drug that was indicative of a potentially, not necessarily it was, but a potentially impairing condition. And to sort of tie into our medical certification, this is a subset of data from 2005 to 2012. It looked at pilots that had a, like general aviation pilots, so they would have like a third class medical certificate, with or without a special issuance, versus pilots that had, either had them expired, or didn't need them. So, as you can see, and which was also statistically significant, is that there is a larger number of study pilots that had positive findings when, who either had expired or no medical certificate. Now of course this is a little bit hypothesis generating on why is that so. Because we do have a different population. So could it be that we have more impairing conditions because the pilots say like, hey I'm not going to even bother getting a medical certificate, or yeah, you know what, I'm just going to do gliding now, because I just can't do the other things, because I can't get a certificate. Or, on the plus side, is it that for some of the conditions, again they're allowed and FAA does offer special issuance, do you end up having enough counseling by the medical examiner that you end up having sort of a less number of those. So again, can't tell from the data, but it is interesting in terms of their certificate. This was actually, analysis was done to try to provide some free information before pilots went to the whole program of basic med, which is a whole other discussion. Alright, so our last case then is another railroad and another shelving accident. So this one occurred in california, but this time it's at little after midnight, so pretty dark. While it's a clear enough night, it's, you have some ambient lighting in the rail yard, you have across the way, you'll see there's like a warehouse that has some ambient lighting, so not great lighting. So the conductor and engineer were talking and the idea was, oops, you'd think i'd master it by this point. So the idea is, you're going to bring this train back onto these two tracks and separate it sort of in half. And what you did is you left the two rear locomotives here, about 30 some cars over here, you move forward and then you're going to shove the front pack of the train, and the idea is they agreed that they were going to shove it back onto this rail and they were going to do a 25 count and they were going to use these palm trees as a landmark to tell them when to stop. Okay, so unfortunately what happened is the conductor and engineer are communicating, they're doing this countdown from 25 cars, 25, 20, 16, 9, 7, and the conductor starts saying stop. So the engineer stops, but the locomotive's doing about 8 miles per hour, so he does the right thing and he stops, and as you continue down the communication gets more emphatically stopped and unfortunately then the conductor who's riding on the rails of the boxcar gets pinned next to the locomotives of that rear section of the train that they had dropped off on the other track. So, still not, learning curve's slow here. So here's our warehouse and our palm trees that he was supposed to see and on the right-hand side here's this orange paint marker that was also a landmark for saying hey, this is where you want to stop your shoving movement. So in response to this, the company did try a pilot program of using paddle markers, so something a little bit more indicative for stopping the rail movement. Let's look at our conductor. This one, occupational medicine, not quite as clean as the other guy. Okay, because though hired in 2013, you know, reasonable experience but not as many years, but he did have a medical leave in the spring of 2015 because it had turned out he had an M.I. with stenting, so a young guy, 46-year-old guy, has to have an M.I. with stenting and while he was in the hospital he gets diagnosed with diabetes. He was returned to full duty in July and first provisionally and that was cleared in August so then you have no occupational medical records about these conditions after that. FRA toxin clear. Our FAA toxin testing shows hey, he was taking his blood pressure medicines as he was prescribed. Gosh darn it. Okay, there you go, the ending. However, wow, what's this with his urine glucose? So you look at hemoglobin A1C, it's like well, that's not bad, this doesn't jive and you sort of say yeah, but hemoglobin A1C gives you a picture for 90, 120 days. Was something happen acutely, a blurred vision, whatever, mind thinking, whatever. So we went back, this was in L.A. County, so they had some vitreous fluid that they had kept for their own records, so we talked to them and they agreed to test it and the vitreous glucose turned out to be somewhat normal. Maybe two months after the fact, there was a little bit of give and play in terms of how much glucose would be left, but that was normal. So we did get personal records and as you'll see, what we found with his diabetes treatment, he had the dapagliflozin or also known as Farsiga and that's a sodium glucose co-transporter that works by having excessive glucose excreted into the urine. So that was a source of that. So again, the medical records were like when you have an abnormality that we find in tox, you go back and you try to like, we're trying to rule out any potential causes for it. As you'll see, in this case, it wasn't even like we can't determine, it was like hey, we don't think there's anything medical about this case. So, key points on toxicology. Always, everything provides some information it's just a matter of how well you can interpret and what other things you need to help figure it out. Always we consider whether the drug or the condition is more impairing and whether, you know, that we bear in mind the present doesn't equal impairment and really for our post-mortem samples, there's a whole other slew of things that we have to take into consideration in terms of post-mortem redistribution, the condition of the body and a few things like that. We now know the approach we've taken and again, we can't find everything has something that might be medical in terms of its condition. You know, some of the things that we find in terms of what we look at mostly for impairment or incapacitation from the medical side and with that, you know, here's my contact information and do you have any questions? I think I've got I think we've got maybe a few minutes for questions if there is any. There is one. Or is he leaving? Question from audience Question from audience Question from audience Question from audience Question from audience Question from audience Question from audience Question from audience Well, thank you. I mean I should mention that. So we are not regulatory. So anything that we conclude or present is not, you know, while you're saying, well, what standard do we hold to? I would say when we're judging things, it's sort of we have loosely we have causal like yeah, we're pretty convinced it's causal. Like our example with ventricular tachycardia and we've had others where the person has a heart attack on the plane. You know, much more straightforward to a contributing factor to the accident. Because even with medications, you realize there's other things that are involved operationally that do that. Then we have that in between it's like, you know, I can go either way. I can make an argument both for and against. And in terms of your first part of your question, is that as medical officers, we do discuss that amongst ourselves. Like we each have our own cases, but we're like, hey, I have this case. You know, this is sort of where I'm at. We weigh in with each other. Though we also weigh in with their survival factor people and human performance people. So some of it's discussions with other experts to come to our conclusions. And then finally it's like, eh, maybe there was some odd thing that we don't know about this, you know, say on our last case, but we're never going to be able to figure it out and everything we have does not point in that direction. And as I said, what we try to do is be as thorough as possible without invading too much privacy as well as having massive amounts of records that we don't need in terms of trying to really narrow down the things we have. Thanks. So often NTSB events wind up somewhere. Do the medical students get wind up in front of the president for testifying? Okay, so I would argue that actually while we had FOIA'd a lot for our information on the public side of the docket that's available as well as some other things, medical is actually pretty secure on that. And in this agency, the medical officers and most people are not made to testify. I'd say some of the exception actually has to be with some of our engineers who are like some of the recorder specialists that there's no other public entity that does it. So that's why they get to be expert witnesses. But other than that, this agency is pretty much, we pretty much refuse being, or have that or have not done that. Thank you. Okay. Well, because of the audience, i have only focused on the medical. And so even for that case, if you look up that, you know, accident numbers on all of them, you will see there's a huge report that goes through every single aspect of the case. And so i, for the purpose of the audience, i felt the medical was important. You don't need to need to discussion all the things they want in terms of the Other levels. There is probably about a dozen Different recommendations for all sorts of things related to that accident. Including some of them where we are desired to have forward-facing cameras And rear-facing cameras in a lot of the commercial vehicles, because Obviously that's helpful in terms of figuring out an account. So there's so many aspects of that case, and i really did focus on the medical. Thank you. Yeah, and i'd say the best example of that, i think i gave, again in utah, Was the scurry accident, which was a limousine accident. And actually the medical was not part of that final conclusion either, Even though the driver had bipolar disease, he had marijuanas and System and everything else. But the focus was really more on Some of the licensure and some of the other aspects of the Limousine company, the oversight of the limousine company, the rules in Place for them, and so everyone, like each group has so many people That actually are working, and some of them say, hey, nothing here. Others say, hey, there's this, and depending upon how, i shouldn't say Egregious, but potentially like how much they need to make or what kind Of recommendations they could make from it, we'll go forward with that. I'm curious if the publisher is Considered asking for more availability of The medical examiner. Yes, but not, you know, unfortunately that is a difficult topic in terms of That because how do you start out with the medical examiner often has no Relationship to the applicant at all, and so you rely initially on some of That forward part. I think most of our recommendations From that and others are like, yeah, but at least when you are getting Information, let's make that information meaningful as opposed to Such a superficial layer that you tick a box and it's good. It obviously is quite challenging to sort of have an applicant, and even Then the applicant says, you know, again, i'm sure there's some 50-year-old Doctor, i haven't seen a doctor in three years, what record are you going To give me, even if they are. So you still always will have a Component of the patient reliability or they're seeing two different Doctors but they're only going to give you one who doesn't know about the Other. So it is a little challenging Regardless even in terms of the application of it, so our focus has Been really more on the, for fmcsa, is that the medical examiner should Know that the person, like can't doctor shop, so they at least can Know that the person started an application that's being deferred Or detained. The faa, the way they're electronic System, and again, different volume of pilots that you're Looking at, it's still about 500,000, once the exam is Started, that person got to complete that exam. They can't go somewhere else. And faa knows that, and as does The examiner when they start up, and then they have a record of the Pilots that they can build on. So that's where our focus has been And not trying from scratch. Because even faa, those pilots Truly can misrepresent, not include or don't think they can Include. Maybe let's see what our time Is. Okay. Maybe one final question. Yeah. Well, i think osa is now off that list. I mean, there's sort of more general categories. So one of the big ones now that i'm also involved with, again, There's ten, and some of them have nothing to do with medical Of those ten. Probably fall to impairment. And so we've been doing a lot on both, you know, the medical Study done and look at driver usage of multiple drugs and some Of them pairing, some of them not. Obviously there's a push to go to .05 for ethanol instead of Blood alcohol instead of .08. So there's those kind of Movements in terms of impairment. The osa i don't think actually sort of fell off the list, and Not that it's not a concern. It's somewhat a little buried in Terms of some of the issues related to looking at, say, Driver fatigue and working with other groups in terms of looking At devices that potentially, you know, if you're detecting Impairment from a drug, is that the same thing, or can you use Some of those sensors to see tiredness, for example, that may Or may not be too bad. Okay. So thank you so much for your attention. Thank you.

Dr. Michelle Waters

medical impairment

transportation-related accidents

National Transportation Safety Board

NTSB

independent federal agency

civil aviation accidents

transportation modes

probable cause of accidents

safety recommendations