How does an embolism cause death?

[Mental Gridlock]

When you are floating in the middle of space nowhere near a planet or anything, and then you take your space helmet off, what happens?

Does your head explode from the internal pressure? Or does it expand more gradually like in Total Recall. I figure it would swell up faster than that though, as Mars at least has SOME atmospheric pressure. But with none whatsoever in space, I would THINK it's an instantaneous explosion, but of course I don't know.

Or would you freeze to death first? How would death actually happen, (besides the anoxia). Would you shatter, or still be a corpse? I mean I've seen it happen in the movies but I can't trust them for scientific accuracy and am dying to know. I usually like to find things out by experiment but in this case I'll just ask because my space shuttle is at the shop.

 

[dicerandom]

http://www.straightdope.com/classics/a3_147.html

What a lovely topic for discussion

 

[Moonbear]

http://www.straightdope.com/classics/a3_147.html

What a lovely topic for discussion

Since the latter description reports the cause of death as pulmonary embolism, it sounds like decompression sickness is the culprit (otherwise known as the bends...what divers experience if they ascend from high pressure to atmospheric pressure too quickly, but it can happen with any rapid change in pressure from higher to lower).

http://www.emedicine.com/emerg/topic121.htm

http://en.wikipedia.org/wiki/Decompression_sickness

 

[somasimple]

How do you die in space?

hmmm, quickly?

 

[GOD__AM]

Since the latter description reports the cause of death as pulmonary embolism, it sounds like decompression sickness is the culprit (otherwise known as the bends...what divers experience if they ascend from high pressure to atmospheric pressure too quickly, but it can happen with any rapid change in pressure from higher to lower).
http://www.emedicine.com/emerg/topic121.htm
http://en.wikipedia.org/wiki/Decompression_sickness

A pulmonary embolism is a type of over expansion injury, which occurs when air escapes from the lungs into the blood vessles around the heart. These are usually fatal, and are far more dangerous than decompression sickness.
Decompression sickness has to do with disolved gas coming out of solution (in the blood stream), and forming bubbles in the blood vessles or under the skin.
Not to nit-pick, but they really are two different things.

 

[Moonbear]

A pulmonary embolism is a type of over expansion injury, which occurs when air escapes from the lungs into the blood vessles around the heart. These are usually fatal, and are far more dangerous than decompression sickness.
Decompression sickness has to do with disolved gas coming out of solution (in the blood stream), and forming bubbles in the blood vessles or under the skin.
Not to nit-pick, but they really are two different things.

Where did you get your definition of pulmonary embolism? Pulmonary embolism is when a blood clot enters the lungs. http://www.nhlbi.nih.gov/health/dci/Diseases/pe/pe_what.html
http://www.mayoclinic.com/health/pulmonary-embolism/DS00429
http://www.emedicine.com/EMERG/topic490.htm
Air bubbles in the blood stream, as occur in decompression sickness, can cause such emboli. The overexpansion injury you speak of can also be part of decompression sickness.

Did you read the links I provided? They explained all of this:
In http://www.emedicine.com/emerg/topic121.htm

Thrombi may form because of the activation of the early phases of blood coagulation and the release of vasoactive substances from cells lining the blood vessels. The blood-bubble interface may act as a foreign surface, causing this effect. Bubble formation in DCS has been believed not only to cause mechanical stretch or damage and blockage of blood flow by embolization, but also to act as a foreign body and to activate the complement and coagulation pathways, creating a thrombus. Recent studies appear to leave this concept unresolved. Some of the studies' authors indicate that they have supported this hypothesis, while others could not find a correlation with degree of injury.

and

Arterial gas embolization

Pulmonary overpressurization (see article on Dysbarism) can cause large gas emboli when a rupture into the pulmonary vein allows alveolar gas to enter systemic circulation. Gas emboli can lodge in coronary, cerebral, and other systemic arterioles. These gas bubbles continue to expand as ascending pressure decreases, thus increasing the severity of clinical signs. Symptoms and signs depend on where the emboli travel. Coronary artery embolization can lead to myocardial infarction or dysrhythmia. Cerebral artery emboli can cause stroke or seizures.

Differentiating cerebral AGE from type II neurologic DCS is usually based on the suddenness of symptoms. AGE symptoms typically occur within 10-20 minutes after surfacing. Multiple systems may be involved. Clinical features may occur suddenly or gradually, beginning with dizziness, headache, and profound anxiousness. More severe symptoms, such as unresponsiveness, shock, and seizures, can quickly occur. Neurologic symptoms vary, and death can result. DCS of the CNS is clinically similar to AGE; since the treatment of either requires recompression, differentiating between them is not of great importance. During the numerous dives involved in the recovery of wreckage from TWA Flight 800, rapid ascents resulting in AGE were uncommon even under stressful conditions.

 

[Mk]

Air bubbles in the blood stream, as occur in decompression sickness, can cause such emboli.

Emboli? Sweeeet...

 

[jhe1984]

Actually, in Jane Russell's book I think, she talks about this curious and slightly disappointing problem for us humans in space. I think Steven Hawking mentioned it as well. As Moonbear said, the problem is decompression sickness like the bends: something like too much nitrogen in the lungs.

Interestingly, if an astronaut were to take his space helmet off in orbit, he/she could survive for around 30 seconds provided they DONT hold their breath.

If you do hold your breath, you're a gonner. I have not completed my thesis yet, but I believe its because the mini-aliens in space invade your eyes and beat on your head from the inside out, thus causing a splitting headache that proves lethal.

In seriousness though, I am not sure that this problem is intrinsic to space per se, but possibly to the simple poisonous differences between the pressurized breathing (like in deepwater SCUBA) and extreme pressure disparity of the outside, new intake "air". I am not sure if this is the way a human would die if, say, he or she could simply float up into space (smell something burning?) without any pressure suit. I want to say I've heard from one professor that the stark absence of normal gravity would cause our internal organs to drift apart [and possibly tear], but don't quote me on that one.

Again, the aliens...

 

[Qev]

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html"
No real swelling up and exploding... you just suffocate :yuck:, assuming you didn't try to hold your breath.

 

[DaveC426913]

BTW, don't forget that 100% of all deaths are from the same cause: lack of oxygen to the brain*.
.
.
*Now, whether the brain isn't getting any oxygen merely because the lungs don't contain any, or because the brain is a football-field's length away from the lungs, and getting farther away every minute - that's not mine to answer...

.

 

[quetzalcoatl9]

if you consider not taking off the helmet, then you could enjoy a plethora of alternative scenarios, such as radiation poisoning, bone degradation, vascular dysfunction, and other slower processes. not a very nice place for an earth-born organism to live.

while this response was meant to be somewhat funny, en serio this is probably the most difficult hurdle for humanity in exploring our solar system since the orbital mechanics of our local planetary system do not permit rapid travel between locations. if we compensate by increased propulsion, then you hit the other biological limit: the body being subject to massive forces beyond it's limits. if you try to cut the problem in half by rejecting prospects of returning to earth, then you still have the limit of long-term life in non-earth conditions. it's a no-win situation as far as our current understanding allows, unfortunately.

 

[DaveC426913]

if you consider not taking off the helmet, then you could enjoy a plethora of alternative scenarios, such as radiation poisoning, bone degradation, vascular dysfunction, and other slower processes.

None of which will actually kill you until they ultimately lead to oxygen deprivation of the brain.

 

[Curious3141]

Where did you get your definition of pulmonary embolism? Pulmonary embolism is when a blood clot enters the lungs.

To be more precise, the migration of a clot into the pulmonary vasculature should be termed "pulmonary thromboembolism" (thrombus means clot). Decompression can cause gas embolism, which is a different sort of embolism, but with similar effects to thromboembolism.

Embolisms can occur with quite a few different things. Apart from sterile clots and gases, it can occur with amniotic fluid (in labour) and clumps of bacteria (septic emboli). Embolisation can even be therapeutically induced in order to shrink vascular malformations, stop bleeding or shrink inoperable tumors.