Blown out the airlock

[(Psi)SeveredHead]

Anyone remember a golf hero who took a weird trip? The plane, which was flying at high altitude, developed a hole (how?) and everyone fell unconscious almost instantly. The plane then flew in a fairly straight line, pursued by fighter jets. This all happened more than a year before September the 11th (it probably would have been shot down afterwards).

"Some degree of consciousness will probably be retained for 9 to 11 seconds (see chapter 2 under Hypoxia). In rapid sequence thereafter, paralysis will be followed by generalized convulsions and paralysis once again. During this time, water vapor will form rapidly in the soft tissues and somewhat less rapidly in the venous blood. This evolution of water vapor will cause marked swelling of the body to perhaps twice its normal volume unless it is restrained by a pressure suit. (It has been demonstrated that a properly fitted elastic garment can entirely prevent ebullism at pressures as low as 15 mm Hg absolute [Webb, 1969, 1970].) Heart rate may rise initially, but will fall rapidly thereafter. Arterial blood pressure will also fall over a period of 30 to 60 seconds, while venous pressure rises due to distention of the venous system by gas and vapor. Venous pressure will meet or exceed arterial pressure within one minute. There will be virtually no effective circulation of blood. After an initial rush of gas from the lungs during decompression, gas and water vapor will continue to flow outward through the airways. This continual evaporation of water will cool the mouth and nose to near-freezing temperatures; the remainder of the body will also become cooled, but more slowly.

"Cook and Bancroft (1966) reported occasional deaths of animals due to fibrillation of the heart during the first minute of exposure to near vacuum conditions. Ordinarily, however, survival was the rule if recompression occurred within about 90 seconds. ... Once heart action ceased, death was inevitable, despite attempts at resuscitation....

It is very unlikely that a human suddenly exposed to a vacuum would have more than 5 to 10 seconds to help himself. If immediate help is at hand, although one's appearance and condition will be grave, it is reasonable to assume that recompression to a tolerable pressure (200 mm Hg, 3.8 psia) within 60 to 90 seconds could result in survival, and possibly in rather rapid recovery."

Note that this discussion covers the effect of vacuum exposure only. The decompression event itself can have disasterous effects if the person being decompressed makes the mistake of trying to hold his or her breath. This will result in rupturing of the lungs, with almost certainly fatal results. There is a good reason that it is called "explosive" decompression.

I'd suggest either giving them two rounds to live or be rescued, or give them some sort of Fortitude save, with a DC low enough that they could survive a few rounds. Note that there is a delay between unconsciousness and death, so they can still be rescued (Telekinesis, anyone?)

Once their heart gives out, you'll need a Heal spell or a Heal skill check with a really high DC to keep them alive.

Another note, explosive decompression causes a loud noise but isn't actually fatal (you don't turn into pink mist

Hope this helps.

[evil thought] Psionic villain tosses someone outside of an airlock, then manifests Crisis of Breath on them. Even if you somehow rescue them, you won't be able to make them breathe again until they regain consciousness. [/Evil thought]

Edit: Explosive Decompression.

 

[Magus_Jerel]

Normal air pressure is somewhere around 15 psia. How deep underwater do you have to go to get to 30 psia? I don't know off hand, but it isn't very far since water is very dense. So dive to the depth of 30 psia and spend enough time there to completely acclimatize, then suddenly surface. Physiologically it should be similiar with respect to the disolved gasses in your blood boiling (assuming that gas soluability in a liquid is reasonably linear with respect to pressure in that pressure range). Is that deep enough for the bends to affect someone?

At STP - air pressure is 16.4 psi
for every 20 feet down in seawater - you add another atmosphere. The danger - is actuall holding your breath, as previously mentioned - this is what kills you.
Submarine Escape Training...
This is for rapid decompression.

Actually, there once were NASA tests done in vacuum chambers...

I forget whether the test was purposefully testing the effects of decompression, or it was an accident while testing a space suit, but a astronaut was exposed to (near) vacuum for several seconds.

He survived easily, but relates the sensation of having moisture boil off of his eyes and tongue, because the pressure is so low.

This is one of the few documented and studied instances of explosive decompression. What is known is that the blast is forceful enough for your lungs to be "deflated" instantaneously. The major factor is believed to be the oxygen content of your blood at the moment of decompression. For D and D purposes - this might as well be holding your breath. The other "nasty" effects that exist won't come into effect fast enough to "kill" the character.

 

[AuraSeer]

It's a game, guys! In d20, decompression should be survivable, because instant death is boring. If you want it to be realistic, you're playing the wrong RPG.

 

[SableWyvern]

If you don't want instant death, you are also playing the wrong game.

(save or die is as good as..)

 

[Jack Haggerty]

It's a game, guys! In d20, decompression should be survivable, because instant death is boring. If you want it to be realistic, you're playing the wrong RPG.

• Cloudkill
• Circle of Death
• Disintegrate
• Finger of Death
• Power Word, Kill
• Wail of the Banshee
• Slay Living
• Destruction
• Word of Chaos
• Implosion
• Sphere of Annihilation
• Slaying Arrows

What game are you playing?

 

[Storminator]

So summarizing and theorizing:

Round 1: Reflex Save to avoid holding breath (ie death); DC 15

Round 2: No effect

Round 3: Fort save to avoid paralysis; DC 19

Round 4: Fort save to avoid unconsciousness; DC 23

Round 5: Paralysis

Round 6: Unconsciousness

Round 10: Last round to revive character after rescue

Round 15: Death

Gives a couple extra rounds if you make your saves, but pretty quickly leading to nasty results. Easy to administer. Actually sounds like a fun encounter!

How much experience? CR = PC's level - 1? Should remain a fairly harrowing experience at all levels, that's why I base the CR on the PC's level, but does that sound reasonable?

PS

 

[Ridley's Cohort]

I am probably incorrect about holding breathe being impractical in a vacuum but I think the jury is still out.

As already pointed out 1 atmosphere is only the difference of ~20 feet of water. Submarine training for blowing out your air are for people who may well be 100' feet underwater (or more). The decompression effects of the bends, IIRC, are something divers who spend significant time more than 60' down.

I am sure there are some experienced divers out there who can tell you what happens when you attempt to hold your breathe and rise 20' quickly. I would point out you can do nearly the same thing in a large, deep swimming pool. Swimming pools with real diving boards are typically ~15' deep. One could do a reasonable experiment by rising slowly while holding ones breathe after using compressed air with no practical risk; you could blow out the air if it becomes very uncomfortable.

 

[Jack Haggerty]

Ok, here's what I'd do...

1. The character has a chance of dying outright due to embolism or hemmorage by expanding gasses in the lungs. Use the "Massive Damage" rule: Fort Save vs. DC15 or die.
2. The character has a chance to get sucked out the hole. I'll assume that a character that can grab onto something quick enough can save himself. Ref Save vs DC15 or get sucked out (any possible damage should be determine by the DM).
3. The characer no longer has any air to breathe... USe the standard "Drowning Rules". Hold breath for 2xCon rounds. Every round after that, Fort Save vs DC 10+1 per previous check. Failure = 0hp and dying.
4. It is also incredibly cold in space. Use a modified "Cold Exposure Rule". Every partial action (twice per round), the character rolls a Fort Save vs DC 20+1 per previous check. Each failure deals 2d6+1 per previous check subdual damage, and the character is fatigued. If the character is unconcious and fails his Fort Save, then hp go to 0 and he is dying.

So, this way, there is a small chance of dying straight off. If you survive that, it's the cold that will knock you out. Then, it's a toss up whether the cold or the lack of air kills you first.

 

[Storminator]

As already pointed out 1 atmosphere is only the difference of ~20 feet of water. Submarine training for blowing out your air are for people who may well be 100' feet underwater (or more). The decompression effects of the bends, IIRC, are something divers who spend significant time more than 60' down.

Actually one atmosphere is 33 feet of water. And it hurts like hell if you try an emergency ascent without exhaling from that distance.

It's not the bends that hurt at that depth, it's anurisms (sp?). I.e. the expansion of gas in your lungs forcibly injects those gases into your blood stream.

PS

 

[Ridley's Cohort]

[*]It is also incredibly cold in space. Use a modified "Cold Exposure Rule". Every partial action (twice per round), the character rolls a Fort Save vs DC 20+1 per previous check. Each failure deals 2d6+1 per previous check subdual damage, and the character is fatigued. If the character is unconcious and fails his Fort Save, then hp go to 0 and he is dying.

The cold is a non-factor on the scale of several minutes. This is because you will only cool by evaporative and radiative cooling. Radiative cooling is very slow. Evaporative cooling might be a problem, but that will be the low on your list of worries unless you somehow find the air to breathe somehow.

I think the simple thing is to make a Fort save every round after the first, bumping up the DC every round. Fail and you lose consciousness.


Upon reconsideration, if you knew you were about to be exposed to vacuum, I think you have two plausible options:
(1) Exhale completely and hold your breathe. The residual air will expand to fill your lungs but not be an unmanageable volume or pressure. (This may not work if "empty" lungs have volume more than ~1/4 of "filled" lungs.)
(2) Hyperventilate and hope the extra oxygen in your blood stream will help.
Either way will probably only make a difference of a few seconds over doing nothing. When the partial pressure in your lungs drops sharply you will be losing oxygen out of your bloodstream into your lungs quickly no matter what you do.