Can you kill a person with a rear naked choke?

[beeble]

id say dont try it.. but yes it can kill someone... would u think someone could live underwater? same thing happens with a choke, no oxygen, you die

oxygen = good /thread

 

[damit2hell]

been choked out, have choked out people, its not that bad . like hitting the reset button... i dont see why people are so petrified of it

 

[Belatucadros]

id say dont try it.. but yes it can kill someone... would u think someone could live underwater? same thing happens with a choke, no oxygen, you die

oxygen = good /thread

did you /read the thread? like, the words? can you read this that I am typing right here?

 

[MonkeyNuts!]

The reason i was under the impression that the bradycardia caused the unconsciousness not the deoxygenation of the brain, is i thought the brain could survive for some time with the oxygenated blood already in the brain before needing to shut down consciousness to conserve oxygen. Is it possibe for the person to go unconscious within say 3 seconds through the blood constriction alone?

Oxygen delivery is characterized by the oxygen hemoglobin dissociation curve. In the blood, oxygen is carried by hemoglobin.

There's some molecular biology and hematology behind this, but basically, when the curve shifts to the right, you get oxygen unloading of hemoglobin and delivery to the tissues. Factors that shift the curve to the right are listed on that graph: increase in 2,3 diphosphoglycerate, decrease in pH, and increase in temperature.

The effect of exercise on 2,3 diphosphoglycerate has not been elucidated, some studies think exercise increase it, some say decrease, and some say no change. Let's just ignore it for now. A decrease in pH means acidosis, and this is evident in exercise, as hypercarbia results from muscle work. Increase in temperature is due to ****bolism, and again work by tissues. So in exercise, not only is there increased stroke volume (blood pumped from heart, increases due to increases in contractility) and heart rate (sympathetic nervous system response) to increase cardiac output (CO = SV x HR) as well as increased breathing to ventilate, but oxygen unloading is also increased to meet oxygen demands.

So in the brain, which is an oxygen and glucose hungry organ to begin with, exercise would increase unloading even more. Thus, deoxygenation of blood that is in the brain during RNC compression would be faster. While I believe the amount of time needed to exhaust oxygen supply of this remaining blood is quick, the exact time (whether it can be three seconds or ten or twenty) is hard to say, probably differs from person to person, and depends on many, many factors - ie the aforementioned O2-Hgb curve, PO2 of the person's blood, and even the existence of hemoglobin defects or impairments in blood flow make the time of deoxygenation vary. I still also think that bradycardia, even though mechanical activation to severe levels could lead to loss of consciousness, is highly unlikely to contribute to the effects of an RNC in the face of increased sympathetic activity.

id say dont try it.. but yes it can kill someone... would u think someone could live underwater?

I should also point out that this is a little different than the scenario where you are drowning - which has been referred to on this thread twice already. If you are not breathing and are suffering from some sort of respiratory failure, if your heart is still pumping, your brain is STILL getting oxygen for some time, because it is still being perfused.

Mixed venous blood, or blood returning to the heart, is not completely devoid of oxygen. The PO2 of this blood is generally around 40 mmHg. On the oxygen hemoglobin dissociation curve above, that's an oxygen saturation of 70%. So as long as the heart continues to pump this blood, even if you aren't breathing, there is still enough oxygen in your blood to perfuse the brain (and the rest of your body) for a period of time. TyroneSlothRop on page 2 mentioned fishing kids out of freezing water. Remember that a decrease in temperature shifts that dissociation curve to the left - a PO2 of 40 mmHg would be even higher oxygen saturation and decreased unloading. This is why in CPR, the chest compressions are more important than the rescue breathing. Eventually, all the oxygen in your blood would be used up and you would die, but for some time, there is still a window of rescue. There are other autoregulatory mechanisms in the body such as vasoconstriction that actually shunts blood to critical areas like the brain to help widen this window.

In the RNC compression scenario, you are blocking 80% of the flow to the brain. It would be the equivalent of having an instant clot in both your internal carotid arteries. There is no continued perfusion other than the 20% through the vertebral arteries - and in a period of exercise where oxygen unloading is increased significantly, ischemia of the brain can generally occur much sooner.

So using the drowning example to define the timing of brain damage and death in comparison to RNCs (even though both result in ischemia) may not be appropriate because the oxygen unloading and perfusion effects are different.

 

[lolbjj]

cool info, man. thanks.

 

[codemonkey76]

Excellent Info EternalRag,

Regarding the "Blood KO" mentioned already, I am wondering if the mythical pressurepoints to make someone go unconscious have some basis in fact. pressing in the right are with sufficient force to cause bradycardia and subsequent unconsciousness, or is it too far fetched?

 

[MonkeyNuts!]

Is this the mechanism behind the elusive 'blood knockout' that some people claim will occur if the carotid is struck with enough force in the right manner?

I've searched around the net, and yeah, it seems some believe that a strike to a carotid sinus can cause rapid bradycardia and hypotension. Whether this can actually happen or not, I am uncertain because I don't know how hypersensitive a carotid sinus can get.

My gut feeling says if you're in a fight and your sympathetic tone is raging and heart beat racing, I would imagine it's pretty difficult to go from that to dangerously low levels within a split second. I'd also probably think that an RNC would do it over a strike because baroreceptors are stretch receptors and would probably require a constant mechanical stress to decrease blood pressure and heart rate.

But since the function of the sinus is for that sort of regulation on a relatively slower time course in normal individuals, my gut feeling also says that it isn't out of the realm of possibility for those who have varying anatomy and physiology in the extremes, just damn near impossible. My knowledge and experience with real patients is much too limited to answer if something like this actually happens in real life with any sort of significant frequency.

Regarding the "Blood KO" mentioned already, I am wondering if the mythical pressurepoints to make someone go unconscious have some basis in fact. pressing in the right are with sufficient force to cause bradycardia and subsequent unconsciousness, or is it too far fetched?

I'm not familiar with where exactly these martial arts systems say the pressure points are. I personally believe those that are based on some sort of chi system or chakra control (lol naruto) are just science fiction. Granted there are studies that show the positive effects of practices like tai chi or meditation (tho not the mechanism of action), I'd rather put my faith in molecular and cellular biology when it comes to discussing things like chi.

The idea of a mechanical activation, actually trauma, of a receptor leading to an incredibly rapid and severe detrimental physiological response probably would require the exact combination of a giant number of factors, including the mechanics of the strike or whatever method of inducing stress. Again, my gut feeling is no in the majority of people, may be possible in the tiny minority with physiologies and anatomies that are compatible.

My interest is thoroughly peaked. Tomorrow I have lectures all day on valvular heart disease from cardiologists, I will ask one of them what they think of this.

 

[w0rM]

EternalRag3 - Thanks for your contributions and let us know what your lecturers have to say!

 

[LinkFC]

I've searched around the net, and yeah, it seems some believe that a strike to a carotid sinus can cause rapid bradycardia and hypotension. Whether this can actually happen or not, I am uncertain because I don't know how hypersensitive a carotid sinus can get.

My gut feeling says if you're in a fight and your sympathetic tone is raging and heart beat racing, I would imagine it's pretty difficult to go from that to dangerously low levels within a split second. I'd also probably think that an RNC would do it over a strike because baroreceptors are stretch receptors and would probably require a constant mechanical stress to decrease blood pressure and heart rate.

I can tell you from experience that during carotid surgery, patients can quickly become bradycardic to the point of arresting. This can happen when the surgeon manipulates the carotid artery, even when the patient is under some stress with elevated heart rates. So I would say that it is possible though not really likely.

 

[MonkeyNuts!]

Interesting. What exactly do you mean by manipulate?

 

[Belatucadros]

I had images of flicking it with your fingers, wiggling it, etc. This may not be the case.

 

[codemonkey76]

post to see hidden post

 

[Byron Pechorin]

been choked out, have choked out people, its not that bad . like hitting the reset button... i dont see why people are so petrified of it

...Brain damage.

 

[LinkFC]

Interesting. What exactly do you mean by manipulate?

Just lifting it or putting pressure on it during surgery.

 

[MonkeyNuts!]

Ok, so today I spoke with a professor after lecture. He is an MD and the chief of cardiology at one of our hospital sites.

Cliff note version of the following post: Compressing the carotid area can cause adverse effects, especially in patients in a medical setting. Even so, "Blood KOs" are unlikely. Pretty much what we surmised so far.

I started off with a clinical situation, because in this thread and also other online discussions of the "blood KO", the carotid sinus massage has been referenced to try and explain the idea of a strike to the carotid sinus in a normal exercising person.

My first question to the professor asked him to describe the circumstances behind cardiac sinus massage as a tool to diagnose or treat patients, and the risks of loss of consciousness (LOC) or worse.

His answer was that in patients with coronary artery diseases or other cardiovascular illnesses, those who receive cardiac sinus massage are to be carefully electronically monitored (on ECG and vitals monitor) for O2 saturation, heart rate, and blood pressure. He stated that even when doing cardiac sinus massage, you are also cutting off blood supply via the internal carotid arteries. So brain ischemia also contributes to LOC/death, along with bradycardia and hypotension. I made a mental note to ask him which one contributes more in an RNC compression applied to a healthy exercising person, but I forgot. I will be sure to ask next week, since this was codemonkey's original inquiry.

I asked if it were possible to get LOC from baroreceptor reflex alone, even without compression of blood flow to the brain, and his response was yes.

Then I asked how long it would take to administer cardiac sinus massage to a point where the drop in blood pressure and heart rate causes LOC or worse.
He said that it is hard to say and also varies for different people with different diseases.

He stated that causing these adverse effects obviously isn't the intention of a physician (nor is used in healthy individuals), and the technique is stopped once normal levels of blood pressure and heart rate are achieved. Those who use the technique for diagnosis and therapy only do so usually for a period of no more than 10 seconds.

I asked if it were possible to cause LOC or worse in a healthy, exercising (and therefore tachycardic with increased blood pressure) person by sudden trauma to the carotid sinus.

His answer was that it is extremely unlikely, and would require a normal individual to have a very hypersensitive carotid sinus, which is not common. I went on further to narrow down the trauma to a strike or a hit to the carotid area, like in contact sports. He stated that a hit is only a sudden event, and you need a more continuous activation of the receptors to get a severe physiological response. He went on to say that if it were to happen, it would absolutely have to be in a person with carotid sinus hypersensitivity.

The professor also told me that the cardiac sinus massage is a tool used in treating arrythmias and that we were going to be lectured on arrythmias next week by a different professor. Apparently that lecturer is a doctor with extensive experience not only in treating arrythmias but also medical research concerning the carotid sinus.

I'm going to ask that lecturer about this topic next week and will tell you all what he says. My questions to this professor were kind of haphazard, and I will try to be more clear and organized in my inquiry next week.

 

[DeathDeela]

hmm, no oxygen to the brain.... Yes u can kill someone with a rear naked Choke if you hold it long enough. HMM...

 

[codemonkey76]

I hate how so many people just read the thread title and respond. Obviously just trying to up their postcount

 

[MiaWallace718]

I hate how so many people just read the thread title and respond. Obviously just trying to up their postcount

Yeah I agree..... What are we talking about?

 

[BeRGLeZ]

I would have thought 20-30 seconds = death.
If it takes 4 solid seconds to put them to sleep, I wouldn't have thought it would be too much more for death.

 

[FyouKantCme]

rear naked choke= lethal force.