let's be clear we've all seen the video by now it's obvious these former police officers killed
George Floyd the Hennepin County Medical Examiner and the medical examiner hired by the family of
George Floyd have concluded that his death was a homicide but their opinion differs on the cause
of death but if both of them declared that his death was a homicide does the cause of death
really matter yes because the trial is going to involve all of these former police officers and
their defense will likely hinge on this specific topic now I want justice for George Floyd and
that's why I'm making this video because the medical explanation for the cause of his death
is not a simple explanation it's actually more complicated than most people think so I'm gonna
break down from a medical standpoint what led to his death for those of you who don't know me
I'm dr. Mike Hansen I'm board-certified in three specialties internal medicine pulmonary disease
and critical care medicine as a pulmonologist part of my job is to figure out why people
can't breathe as an intensive care doctor part of my job is to care for people who are on the
brink of death like when someone can't breathe sometimes people die in the intensive care unit
and part of my job entails pronouncing death and then completing a death certificate form where I
have to put down what caused the death and this is more of a gray area than most people realize
because the cause of death is just about always multifactorial meaning there are actually lots
of causes that either directly or indirectly lead to death so I'm gonna ignore the topic of
brain death because that's a separate discussion by itself and not really pertinent to this video
so for all intents and purposes when someone dies that means their heart stops pumping and they stop
breathing this is known as cardiopulmonary arrest most people don't know that in most states I'm
not allowed to write cardiopulmonary arrest as a cause of death and that's because it's not really
a cause of death because it's always something that leads to cardiopulmonary arrest so there's
always an underlying cause of death that leads to cardiopulmonary arrest for example let's say
someone has a viral infection that call pneumonia and a RDS acute respiratory distress syndrome and
let's say their organs started shutting down because of this so they have kidney failure or
liver failure etc what would be the cause of death in that scenario the answer would be essentially
all of the above the virus started it all and that led to them getting aired yes and they
couldn't breathe on their own and as a result of this their organs started dying and ultimately
that led to cardiopulmonary arrest now what if I told you that that patient was a smoker and had
diabetes and high blood pressure and were morbidly obese well those are all indirect contributors
to the cause of death but not direct causes so really it's always a multitude of factors that
contribute some more than others and some more direct while others are more indirect another
example is let's say when someone with cancer is getting chemotherapy and their immune system
is severely weakened meaning it's suppressed because of that chemotherapy well if they get
a bacterial infection that spreads throughout their entire body meaning sepsis they've been
going to septic shock in multi organ failure and then cardiopulmonary arrest well what's the cause
of death in that scenario well it's really all of the above they're all interconnected and they all
play a part in that so not always but usually the cause of death is multifactorial now before I get
to what asphyxia means we need to understand some basic human anatomy and physiology our breathing
is actually controlled by our brain some of our breathing is controlled consciously with
a big part of your brain the cerebrum but most of our breathing is not done consciously and is
controlled by the very central core of our brain the pons and the medulla the pons and medulla are
very sensitive to three things one a decrease in oxygen level to elevated levels of carbon
dioxide and three a decrease in the blood pH if any of these occur the brain will then tell the
muscles that control breathing to start breathing faster and deeper 90% of the work of breathing is
done by the diaphragm that's the big muscle that goes right here the rest is done by the accessory
muscles of breathe such as intercostal muscles which are the muscles that are in between your
ribs the diaphragms job becomes harder when someone has a big belly such as with pregnancy
or morbid obesity or when someone puts weight on your back if you're in the prone position
when this happens there's decreased chest wall compliance and if it's severe enough it falls
under the category of restrictive lung disease for example when someone is morbidly obese they
have restrictive lung disease well let's say no one is sitting on your chest or your back and
the diaphragm is able to contract without any issues when that diaphragm contracts it creates
a negative pressure inside your chest a vacuum effect this causes air to flow from your mouth
and your nose through your windpipe meaning your trachea and then into your lungs and this
process expands your lungs if you zoom in to the microscopic level of your lungs and take a
look at the alveoli that's where oxygen moves from the air into your bloodstream to be more
specific that oxygen diffuses from the alveoli to the capillaries that surround your alveoli
capillaries are the tiniest blood vessels in your body the oxygen diffuses to the red blood cells
and binds to something called hemoglobin 99.9% of the oxygen in your blood is bound to hemoglobin
the more hemoglobin you have the more oxygen you have in your blood this is known as blood oxygen
content but now we have to deliver that oxygen to different organs of the body such as the brain so
how does it get there the heart has to pump that newly oxygenated blood from the lungs and get it
to the brain using certain arteries the amount of oxygen the heart is able to pump to the body
is known as oxygen delivery there are four main arteries in the neck that deliver blood to the
brain you have two carotid arteries right here and then you also have two vertebral arteries back
here they essentially go the same track as your spinal column while all of this happens carbon
dioxide which is a waste product of your body needs to be removed from the body which happens
when you exhale the blood that is delivered from the body and back to the lungs contains
a lot of carbon dioxide and that carbon dioxide then diffuses from the red blood cells to the a
lie and then you exhale out that carbon dioxide so in the alveoli oxygen is going into the blood and
carbon dioxide is leaving the blood so now that we understand some basic human anatomy and physiology
let's turn to the medical term as fix eeeh this is a Greek term that literally translates to stopping
of the pulse it's a generic term that refers to a condition in which there's inadequate delivery of
oxygen to the body's tissues often accompanied by a retention of carbon dioxide there are
hundreds of different reasons why this can happen usually when a medical examiner is using the word
asphyxia they're referring to airway compromise or compromised blood flow to the brain such as
with mechanical asphyxia but more on that in a little bit so if someone were to die because of
let's say a gunshot wound to the heart technically it would fit that definition of asphyxia but we
would never say that said person died of asphyxia we would say they died because of a gunshot wound
that caused hemorrhagic and/or cardiogenic shock leading to cardiopulmonary arrest so
when someone dies of asphyxia as is the case of George Floyd the determination of cause of
death is dependent on information that's elicited based on the investigation and this includes the
deceased personal medical history the autopsy findings the crime scene investigation which of
course includes video evidence mechanical asphyxia involves some physical force or
physical abnormality that interferes with uptake and/or delivery of oxygen in asphyxia deaths the
brain doesn't get enough oxygen and when the pons and the medulla aren't getting enough oxygen they
can no longer function which means they can no longer tell the diaphragm to contract and
the breathing then stops while this happens the heart is also not getting enough oxygen
and typically when that happens the heart pumps slower and slower until it stops this process is
accelerated if there's an underlying lung disease or underlying heart disease alternatively instead
of the heart slowing down before it completely stops it can go into a fatal arrhythmia such as
ventricular fibrillation and then completely stop now let's talk about some of the different types
of mechanical asphyxia choking there's drowning there suffocation meaning smothering in which
the nose and or the mouth or occluded there's also compression asphyxia which involves the presence
of external force on the chest and/or abdomen that prevents expansion of the chest as occurs
when a car falls on top of a mechanic's positional asphyxia is caused by the position of the body or
part of the body leading to airway restriction vascular compromise or breathing fatigue this
can occur if someone is suspended upside down for a prolonged amount of time when someone is
handcuffed and in prone position and they have a weight on their back and if it's severe enough to
the point where they can't breathe this would be accommodation of compression and positional
asphyxia prolonged continuous application typically minutes of extreme pressure on the
thorax such as with the body weight of several officers is capable of causing death this is
important because this contributed to the death of George Floyd it wasn't just the knee to the
neck but now let's talk about asphyxia as it pertains to when there's pressure on the neck
the neck contains our airway where here is our trachea it also contains big blood vessels as
I mentioned the carotid arteries right here the vertebral arteries right here but also the jugular
veins which go in parallel with the carotid arteries the arteries here deliver oxygenated
blood to the brain while the jugular veins allow deoxygenated blood to flow from the brain down
towards the heart so what happens when pressure is placed on the neck well it depends on a lot
of different factors let's look at what happens with strangulation and hanging strangulation can
be manual when hands or arms compress the neck or can be done with ligature such as with a cord or
a rope or a cloth and that constricts the neck hanging is different from strangulation because
the person's own body weight with a gravitational force is the source of the neck pressure contrary
to popular belief there doesn't have to be full suspension of the body for hanging to
cause unconsciousness or death in other words the body can touch the floor and still cause death
and there's actually two types of hanging there's judicial hanging which is designed to fracture and
locate the upper cervical spine and then there's non-judicial hanging involving compression of the
neck blood vessels with or without significant compression of the trachea restriction of blood
flow to and from the brain is typically the major feature in non-judicial hanging or strangulation
in adults there is a significant difference in the amount of force required to occlude the blood
vessels in the neck and the trachea compression of the neck blood vessels without compressing
the trachea can cause unconsciousness and death in an adult the amount of pressure necessary to
occlude structures in the neck to the point of causing unconsciousness and death is estimated
to be four to five pounds for the jugular veins and anywhere from five and a half to twenty-two
pounds for the carotid arteries anywhere from 18 to 66 pounds for vertebral arteries and to
compress the trachea it's about 33 pounds so these are estimates and in reality it depends on the
body habitus does a person have a skinny little neck or a thick muscular neck it also depends
on the exact location of pressure is the pressure on part of the neck or all the neck if it's only
part of the neck what part of the neck is it on how long is the pressure applied for do they have
underlying carotid artery disease meaning do they have underlying blockages in the carotid
arteries from atherosclerosis and still there are other more indirect factors as well such as
underlying heart disease lung disease and drug use another important question is what are the autopsy
findings in someone who dies of asphyxia well I'll start out by saying there are no pathognomonic
findings for asphyxia by that I mean there aren't specific findings that only occur with asphyxia
and sometimes there are no findings at all with asphyxia however there are findings that are
characteristic of different forms of asphyxia the nature and extent of these findings depend
on the kind of asphyxia for example in hanging and strangulation cases there can be facial swelling
petechial hemorrhages in the face eyes and gums which usually happens when arterial blood flow in
the carotid arteries persists after jugular venous flow has stopped sometimes there can be skin mark
things such as scratches from nails or ligature marks you can also have internal neck structure
damage like hyoid bone and laryngeal fractures and looking at what happened to George Floyd
it wasn't a hanging or strangulation so finding facial swelling or petechial hemorrhage would be
less likely thankfully there was a video in this case because had there not been there would be
no chance of these officers getting prison time a big question that comes up is the timing of
how long it takes for asphyxia to cause loss of consciousness and how long does it take for the
heart to stop after they lose consciousness well that depends there are a lot of variables like
what I mentioned earlier in this video there have been experimental studies and videotaped events of
hanging and strangulation that show rapid loss of consciousness after compression of the neck
typically within 20 seconds in these instances the last breath occurs no later than two minutes
but this is for hanging cases which is not what happened to George Floyd unlike a hanging or lack
of circulation to the brain is the primary cause of death when someone dies of asphyxia primarily
because they can't breathe meaning respiratory arrest they typically lose a pulse around the
same time of when they stop breathing and looking at the George Floyd video he was unconscious for
more than two minutes with the knee still on his neck there's no doubt that during this time
he took his last breath right around the same time that he lost his pulse by the time the EMS
guy checks his pulse I highly doubt he actually felt a pulse because it was more than two minutes
after George lost consciousness it was obvious that when they moved George onto the stretcher
he was completely limp because he was dead and it wasn't until much later did they start CPR
in the ambulance now let's get to what the medical examiners had to say about this case there was the
Hennepin County Medical Examiner and then there was the independent medical examiner dr. Michael
Baden the independent autopsy says Floyd died of quote asphyxiation from sustained pressure when
his back and neck were compressed with the neck pressure cutting off blood flow to his brain I
agree with that assessment that's what happened I would also add that part sheíll compression
of the trachea causing airway compromise was also possible but there's no way to prove or disprove
that because you don't know how much pressure was being applied to that trachea we know that because
George was talking at least some of the time you can conclude that he did not have total tracheal
occlusion for the entire duration of the knee being on the neck but the way on his back made the
work of breathing much harder for his diaphragm to contract in the neck pressure at the very least
meant less oxygen was being delivered to his brain and less carbon dioxide could be removed from his
brain after a while the diaphragm becomes fatigued and no longer has the strength to contract which
means the longest can't get oxygen into the blood and can't get carbon dioxide out of the blood and
whatever oxygen was in his blood well less if it was being delivered to his brain because of that
pressure on the neck and all this caused him to lose consciousness and probably within seconds he
lost the pulse and despite losing consciousness and despite losing a pulse they continued to
apply pressure on the neck and their way on his back as well the Hennepin County Medical
Examiner's Office said that the cause of death is quote cardiopulmonary arrest complicating
law enforcement sub dual restraint and neck compression end quote this statement doesn't
really make sense to me it seems like it's trying to say that police restraint and neck compression
caused cardiac arrest which is like what we talked about asphyxia although they didn't use the word
asphyxia and it did not mention the weight that was being put on his back but the Hennepin County
release also says heart disease was an issue the independent examiner didn't find that but the
county said that fentanyl and methamphetamine were among significant conditions but it's reported to
say how much of either drug was in his system or how that may have contributed so here's the thing
let's say for a second at least hypothetically speaking he had underlying heart disease and he
had fentanyl and methamphetamine and his system so what could those have indirectly contributed
to his death sure but that's not the direct cause of his death a better way to describe it would be
to say they might have hastened his death had he not had heart disease or those drugs in a
system but either way that's not what killed him the officers had their weight on his back
and pressure on his neck for a total of eight minutes 46 seconds and for two minutes and 53
seconds after he lost consciousness so dr. Michael Baden got it right but when he said quote police
have this false impression that if you can talk you can breathe that's not true any quote well
technically if you're talking you are breathing because in order to talk you need to exhale the
airflow going out through your vocal cords is what allows you to make the noise through
your voice box that's what the vocal cords are the process of exhaling is part of breathing so
technically what he said isn't true but I get what he was trying to say I agree with the point that
he was trying to make which is this just because someone can talk doesn't mean they're not on the
brink of complete cessation of breathing Jorge was pleading to breathe he was pleading for his
life and it was taken from him they didn't even bother to save his life when they knew he was
dead they were bystanders they're yelling at them to check for a pulse check for a pulse they didn't
even check for a pulse they didn't even bother to start CPR there needs to be justice for Jorge
you