Doctor testifies on significance of George Floyd's respiratory rates

one two three four five six seven eight so that was a roughly a 17 second clip right and you counted seven or eight set between seven and eight and did you use this to calculate a rate of respiration yes because i mean it's simple once you have 19 seconds and you count out the number of breaths you have here and and if you say you count out seven breaths that will come out at a respiratory rate of 22. is that number uh the respiratory rate of 22 significant to this case it's extremely significant why is that because one of the things in this case is the question of fentanyl and if fentanyl is having an effect and is causing depression of the respiratory centers the centers that control breathing that's going to result in a decrease in the respiratory rate and it's shown that with fentanyl you expect a 40 reduction in the respiratory rate so with fentanyl his respiratory rate should be down at around 10. instead of that it's right in the middle of normal at 22. so you didn't see a depressed rate of respiration or breathing rate in mr floyd no it's normal and and so what does it tell you bottom line with respect to um fentanyl as relates to mysteries exactly with in terms of fentanyl the the major one of the major changes you see in fentanyl is the slowing of the respiratory rate so and again we would be expecting a 40 percent reduction in the respiratory rate with fentanyl the normal risk bursary rate is 17 breaths per minute plus or minus five so that would mean a normal respiratory rate of between 12 and 22 that's the normal range of respiratory rate and so if it was with fentanyl you'd be expecting a respiratory rate above 10 instead of that you counted here yourself and you can see when you counted yourself that the respiratory rate is 22. so basically it tells you there that is there isn't fentanyl on board that is affecting his respiratory centers it's not having an effect on his respiratory centers so mr floyd's respiratory rate was normal at 22 just before he lost consciousness correct so the jury may have heard some other information in the case [Music] about the the fentanyl related to an elevated carbon dioxide level in mr floyd's body in the emergency room was that significant to you yes that's very significant as well how so because he's reported to have a pc or two sorry i take it back is reported to have a carbon dioxide level in the arterial blood in the emergency room of 89 that's a very high level of carbon dioxide and so you have to take into account what are the factors that might have led to that and there's particularly important factors in mr floyd to explain why his carbon dioxide was found at 89 in the emergency room so doctor would you first tell us what would normal have been for carbon dioxide levels the normal carbon dioxide level in you or me is 35 to 45 millimeters of mercury that's the norm you don't need the millimeters of mercury stuff but they're the units that are given in the hospital chart so you said that there were significant factors in the case of mr floyd would you help the jury understand what those were yes the important factors are that we know that he made his own last spontaneous effort to breathe at 20 25 16. after that you can look at the videos and you see he makes no effort to breathe he makes no breath the last breath he took was at 20 25 16. then we know after that he stayed on the street for another three minutes or so then he's placed into the ambulance and we know that in the ambulance they attempted to put in an airway an eye gel and you can see that on the officer lane's body cam you can see all of that happening and then you can see the time at which they actually successfully inserted the airway and when they gave him the first breath and that is a gap of nine minutes and 50 seconds from when he last took a breath and why is that significant that's very significant because we can calculate what is the rate of increase in the carbon dioxide in somebody who doesn't breathe if somebody doesn't take a breath carbon dioxide increases at a predictable rate and that rate is up to 4.9 millimeters of mercury per minute that it increases and so he has not taken a breath for 9 minutes and 50 seconds so you would expect just on that basis that his carbon dioxide level will go up by 49. so you add 49 to the normal values of 35 to 45 and then you add that and you're going to get a value of uh between 89 and uh above and so it comes out ex virtually identical to the value that they found in the emergency room of 89. so so doctor what's the punch line with respect to that what does it tell us the significance of all of that is it's a second reason why you know fentanyl is not causing the depression of his respiration what you're seeing is that the increase in his carbon dioxide that is found in the emergency room is solely explained by what you expect to happen in somebody who doesn't have any ventilation given to him for 9 minutes and 50 seconds it's completely explained by that so when a person then is not breathing then carbon dioxide would naturally continue to build up in the body yes and and that's that's what matches what was seen in the orr for mr floyd precisely [Music] now you said that there were other things that were significant that were related to the rate of respiration and we talked about fentanyl right um was there anything else yes the other thing is there's two other things that are very important to the respiratory rate because you saw it with your own eyes exactly his respiratory rate and the first thing is that if you have somebody who has underlying heart disease and the heart disease is so severe that it's been said that it's causing shortness of breath that it's causing you difficulty with breathing if somebody has heart disease that's causing shortness of breath virtually all of those patients are going to have very high risk periphery rates they're going to have respiratory rates of 35 30 over 30 even over 40 when you have heart disease that will give you shortness of breath instead of that we find that his respiratory rate is normal at 22. the second thing that's important about the respiratory rate of 22 is if you have somebody where the primary problem in the body is airway narrowing where you have somebody where there is that the airways are being compressed there's narrowing in the neck or there's narrowing like in somebody in the chest but the response the physiological response to where we're narrowing is a normal respiratory rate and that is what he has so it's the expect but the respiratory rate that you see that's normal is the expected physiological response in somebody who has airway narrowing hi everyone george stephanopoulos here thanks for checking out the abc news youtube channel if you'd like to get more videos show highlights and watch live event coverage click on the right over here to subscribe to our channel and don't forget to download the abc news app for breaking news alerts thanks for watching

Channel: ABC News

Views: 234,571

Keywords: Tobin, chauvin, day, derek, floyd, george, p_cmsid=2494279, p_vid=news-76951216, rates, respiratory, trial

Id: 2lJ_nWQhJPk

Length: 9min 20sec (560 seconds)

Published: Thu Apr 08 2021