At the trial today a statement was made that if a liquid (blood) was 98% saturated with oxygen there could be no more than 2% of another gas (CO) in that liquid.
Am I right or wrong in remembering from chemistry class that solubility of 2 different gases in a liquid could total greater than 100%? Does this go for 2 different liquids disolved in a gas?
I don’t understand how you can dissolve one liquid in a gas, let alone two.
But, back to your question, I am not sure as I did not see any of the testimony, but I don’t believe the “98% saturated with oxygen” is referring to oxygen dissolved in the blood, is refers to oxygen being carried by the hemoglobin. That is, the 98% is the blood is carrying 98% of the maximum amount of oxygen that the hemoglobin can carry. Interesting enough, carbon monoxide, CO, binds to the same sites on hemoglobin as oxygen does. In fact, CO binds more tightly to hemoglobin than O2, which is why CO poisoning occurs. Even at low CO levels, if given enough time, the CO will displace all the O2 (or at least, enough to prevent transporting enough O2 to maintain life). Because nothing in the body uses the CO, it is difficult to get it out.
Tell that to the carbonation in my beer.
I haven’t followed the trial transcript. Why is anyone even going down this track? I can just barely see asphyxia causing heart attack as a cause of death, but there was a reported 30 minutes of resuscitation attempt – how could anyone have any meaningful data on blood oxygen levels?
As the defense “expert” said, carbon monoxide binds to the hemoglobin better than oxygen and won’t let go, thus impeding the ability to carry enough oxygen. The “theory” is that by lying about two feet from the tailpipe of an idling vehicle, Floyd would have inhaled enough CO to cause medical problems. Nobody seems to have mentioned that hot air rises, so the officers were probably in greater danger.
So saturation refers to the percentage of oxygen bound to hemoglobin, not dissolved. I’m not a doctor (Fremulon!) but it seems to me that active gases like O2 or CO if they managed to dissolve in the blood would bind to hemoglobin at the first opportunity. Note the bends - like beer head - is from dissolved CO2 which does not want to bind with many other compounds.
In the early days of COVID I ordered a oxymeter, which you stick on your finger and it tells you you oxygen saturation. Usually, this for me hovers around 97% to 96%. IIRC when Trump went to hospital with COVID< they said his oxygen level had dropped below 84% - allegedly he had to inhale pure oxygen to do the walk to the helicopter; when he was released from hospital, it was 93% which was not really that great.
So anything other than the 90’s is a blood oxygen saturation level that should cause real concern.
Carbonation is caused by CO2 dissolved in water, not the other way around.
The bends are (is?) usually caused by nitrogen bubbles forming in the blood.
Hey! I’m just reporting what my beer is telling me!
The issue is that hemoglobin has a much greater affinity for CO than it does for O2. Once you are poisoned by CO, it takes a long time to recover. According to Wikipedia, once you start breathing normal CO-free air, it takes over five hours to get rid of half the CO in your body. If you’re breathing pure O2 at atmospheric pressure, it still takes close to an hour and a half:
So if he had toxic levels of CO at the start of a 30-minute resuscitation effort, he would still have problematically (measurably) high levels of CO at the end of that thirty minutes. The fact that he didn’t suggests that CO poisoning was not a factor in his death. This is independent of other issues, like the fact that warm exhaust tends to rise (Floyd’s head was below the tailpipe, not above it). More noteworthy is the fact that modern car exhaust has very low CO concentration, typically 1000 ppm or less. Inhaling it can make you very sick after a couple of hours, but it won’t render someone insensate after five minutes.
Doh!
I knew that! Brain fart time… Must be not enough oxygen.
To get back to the OP, I assume that 98% oxygen saturation means that 2% of the hemoglobin is unbound, at least to oxygen. I know that 96 or 97% is normal. And yes hemoglobin has a much greater affinity for CO than for O2. Curiously, the feeling of asphyxiation is caused by high CO2, not low O2.
This is pure “Chewbacca Defense”, i.e. presenting hypothetically factual contradictions which actually have no application to the issue at hand. Because of the manifest video evidence and multiple eyewitness testimony of the act before and after Floyd’s death, the only worthwhile argument that Chauvin’s defense can make is that the death of George Floyd was incidental to the fact that Chauvin was pushing his knee into the proned Floyd’s neck for nine minutes while the latter protested that he couldn’t breathe and bystanders and even an arriving medical first responder told him to stop. Even if Floyd had less than nominal blood oxygen saturation capacity, it would be incumbent upon a restraining officer to monitor the condition of the person he is restraining, and given that many other people on scene were aware of Floyd’s distress, the idea that this was just an accident is simply not consistent with any evidence.
Since this is evident nonsense—even if Floyd ‘happened’ to have a heart attack or stroke during this time, it would almost certainly be the conclusion of a forensic pathologist that it was likely brought on by the stress of that forcible restraint—the defense is trying to pseudoscience their way out of a conviction by presenting information that they hope will confuse one or more members of the jury into returning a “Not Guilty” verdict, hanging the jury. It is just hand-wavy nonsense to shift the focus onto the victim instead of what the defendant clearly did as plainly apparent in video evidence.
Stranger
One interesting thing I found out is that CO can wreck oxygen transfer without actually keeping all of the O2 out of your blood. A hemoglobin molecule has four sites that can bind to O2. If one of those sites binds with CO, it makes the other three sites more reluctant to give up their O2. So if you are experiencing CO poisoning, your blood may actually have a fairly high O2 saturation, but be unable to hand off that O2 to your cells.
Absolutely. I mean, who cares if he was using drugs, had a heart problem, or was next to the tailpipe? None of that actually makes any difference as to whether Chauvin did the right thing or not, and whether that was lethal or not. The question comes down to whether or not Chauvin’s actions were in line with what the department standards were, and whether they caused Floyd’s death.
All l can figure is that all this smokescreen stuff is aimed at the sentencing phase in hopes of getting a lesser sentence by implying that someone without heart problems or drug use who was equally close to the tailpipe would likely have lived, even considering Chauvin’s conduct. Surely the prosecution will poke enough holes in it in terms of the actual verdict.
Indeed; this is why holding your breath causes misery after 30 seconds or so but people just straight-up fall unconscious and die peacefully from breathing pure nitrogen very quickly. Oxygen deprivation has few symptoms and little pain while carbon dioxide causes the strangulation feeling.
“Sounds like we all agree that there’s no way Derek Chauvin walks away from this.”
“Weeeeell…”
Stranger
Yeah, I saw that the other night too.
[Moderating]
Let’s stick to the factual questions about oxygen and CO in blood, please. Discussion of the circumstances of the Chauvin trial are for other forums.
You have humidity in the air, that sticky feeling is water dissolved in air. If you then under those humid conditions smell another liquid (alcohol, gasoline, ether… whatever) this is another liquid that is also dissolved in that gas. Actually air is not a gas but a mixture of gases, but I hope you get the general idea.
Though when you think of it, as soon as something is dissolved in a gas it is no longer relevant if it was originally a liquid or a solid (or even another gas). The humidity in the air depends on the amount of water disolved in a given volume if air and on the temperature, but it does not care whether the H²O came from water (a liquid) through evaporation or from ice (a solid) through sublimation: the only relevant parameters are the quantity of water, the quantity of air and the level of saturation, which is a function of the temperature.
No, those are all instances of adding more gasses to the air. That is substantially different from dissolving a gas in a liquid.