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lungs colapse

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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primoz kosak

Well-Known Member
Jul 21, 2001
Wonderful page! I want to ask about deep dives - lungs colapse. What is the fluid wich fill the lungs and did this happned to every diver or yust experts? And when you are back from the deep is there any problems with lungs and fluid? In what lungs capacity will fluid start to fill the lungs?

Hi neighbour!

I am not sure what are you talking about , since I've never heard of such event in freediving. Maybe if you could be more specific.
Maybe you're refering to blood shift?
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I think what primoz is talking about is a physiological response that some of the top deep freedivers have been able to develop. The one who comes to mind is Pipin. He has developed the ability to force fluid from his body into his lungs to keep them from collapsing at extreme depths. It has been scientifically documented and is a very unusual technique he has developed.

Since fluid cannot be compressed under pressure like a gas can (air) his lungs no longer are susceptable to collapsing at extreme pressure from the depths that he dives.

To answer your question, though, I am not sure when it actually occurs. Since I do not have the exact information available to me on Pipins techniques, I can only guess at when this occurs.

I can speculate that it probably occurs below 250 feet, but I am only making a guess on this so don't rely on it for a reliable piece of information.

I apologize I couldn't be more helpful on this question
Greetings Primoz

Wonderful page! I want to ask about deep dives - lungs colapse. What is the fluid wich fill the lungs and did this happned to every diver or yust experts? And when you are back from the deep is there any problems with lungs and fluid? In what lungs capacity will fluid start to fill the lungs?

Hi, It is not lungs collapsing, they are compressing as a function of conservation of mass and volume in response to pressure. It happens to everyone who goes deep - approximately every 33 feet your lungs compress by 25% of there current volume. But the pressure is systemic and equal meaning that everything is getting squashed equally over your whole body (except for the stuff store in hard cases such as your brain and spinal cord) so your volume is decreasing but your mass isn't. Because fluids move easier than solids they start shifting into any available nook and cranny. By the time you get past 100 feet your lungs are less than 2/3 the size that they were at the surface. Go another 50 feet or so and they have become the size of grapefruits and are mostly filled with fluids - primarily blood. This is not a willful act or some strange genetic trick - it is just simple physics. As we ascend the fluids are reabsorbed as the pressure diminishes. This is what creates shallow water blackout as well. Under pressure the gases are driven out of our lungs and into our bodies and we feel great because of this. Unfortunately as we ascend the partial pressure reverses pulling the remaining gases out of our bodies (and away from our brains). If we don't have a sufficient reserve of oxygen left for the last 30 feet or so the respitory center in our brainstem is suddenly without oxygen and shuts off. Hopefully this helps, Angus
In an interview last year Tanya Streeter mention that it's pretty scary below 150 feet because her lungs start being collapsed by fluid..."essential, blood" as she put it.
Ill take her word for it.
When I spoke with Tanya last week - she was talking about the fact that she isn't scared when she does her diving. On the contrary - she is quite confident in her capabilities and the physiological response of the mammalian reflex.

Pipin actually tries to encourage this to happen since a fluid cannot be compressed while under pressure (Diving physics here), the fluids that settle into the lungs are actually a help, not a hinderence when descending to those depths.

Stephen - you have any input on this?
Not really

Not really, the whole physiological condition isn't terribly well understood at the moment but the leading freedivers are pushing their bodies hard and it will be interesting to see the outcome of further research.

I think all deep competition freedivers need to have a confidence in their body to be able to do what they do.
Lung Squeeze vs. Lung Fluid

I have some experience with both.

Fluid ie. plasma filling your lungs is a response to the increased pressure at depth (usually at around 50m but it can vary quite a bit depending how much air you have in your lungs and your residual volume) to protect your lungs and other organs. This is a natural, if not a sometimes unnerving experience, which you can get if you do a negative pressure dive in the pool (with a spotter!). You may cough as if you have fluid in your lungs--which in fact you do.

Lung squeeze aka pulmonary oedema is a response to increased pressure as well, but it is harmful, damages your lungs, and, in extreme cases, can lead to secondary drowning.

I suffered from lung squeeze on a dive to 51 metres for which I had done inadequate warm-up and had not been close to the depth for more than a week (stiff ribcage, body loses adaptibility to pressure with time). The dive itself and my recovery was fine, but after a minute or two on the surface, my throat started to tickle, and then I had one of many coughing fits, spitting up a teaspoon of blood from time to time. Other symptoms later in the day included wheezing, feeling like I couldn't get a full breath, sluggishness and fatigue for the rest of the day.

My understanding of this, as Kirk Krack and a doctor explained it to me, was that as the pressure increased, my rib cage stopped collapsing at a certain point and a negative pressue grew in my lungs. In an ideal dive, plasma equalizes the pressure and the rib cage collapses much more. In a lung squeeze, the aveoli are squeezed (flattened) and bleed to equalize the pressure (liquid being non-compressible). Unfortunately, they remain coated with blood long after the dive is over and are unable to perform their oxygen transfer job. Effectively, they are out of commission, until the blood is coughed up or reabsorbed somehow. This condition is not common enough for Doctor's to recognize it right away, but I'm pretty sure that's what happened to me. I can see how this could lead to secondary drowning. Aveoli coated in blood prevent the gas exchange you need for oxygenated blood.

So my advice to everyone is that as freedivers benefit from the knowledge of deep divers (in my case, Eric Fattah) and realize gains in depth much faster than those before us, is to be aware that there may be problems with going to deep too fast other than shallow water black out. So take it easy, give your body time to acclimatize to each depth. And keep your aveoli healthy.

I took a month off from diving to depths deeper than 30m and even then took it slowly to make sure things were okay. Better to freedive when I'm 64 than to drown or wreck my lungs for every.

By the way, as far as I know, plasma in your lungs is not a "technique" invented by Pipin, it's just a natural adaptation of the body.

Awesome information!

:) I can say that you Canadian Freedivers have got it goin' on!

I have learned more on the physiological aspects of deeper freediving than I could have from a text book. Each of you that has participated in the discussions has given answers to questions posted that make it understandable for newbies as well as more experienced freedivers.

My deepest thanks goes out to all of you who have been kind enough to share your expertise with the rest of us here on the Deeperblue.net Freediving Forum
You're welcome, Cliff.

I really do want to freedive my whole life (like Mr. Mayol) and have all my friends still around to enjoy it with me. So I'm happy to pass on any safety knowledge that I learn or discover.

We hope you or someone from Deeper Blue or anyone from the list will make it out here to enjoy the thriving Freediving community in Vancouver, BC, Canada.

By the way, I'm almost finished editing Eric's World Record stories. I'll send them in tomorrow.


Re: Lung Squeeze vs. Lung Fluid

Originally posted by laminar
.........Better to freedive when I'm 64 than........

Hey Pete

64 doesn't sound very old to me.

Let's take a not so hypothetical diver named Bill. He takes a deep inhale, jumps in the pool and uses a tube to try to fill an inverted container with air. Careful measurement yields a volume of 5.3 litres. The figure I was told to use for residual volume is 24%, that makes 1.24 times 5.3 or 6.6 litres total, a little shy of the desired 8.

Same diver at the practice rope exhales to residual (1.3), puts on a mask (0.1) and has air spaces in his head, lots of them(0.05?). He descendsto 30 ft, equalises and the 1.45 becomes 1.45/1.9-0.15 or 0.61 litres in his lungs. Before someone with a room temperature (F) IQ tries this in the bathtub, let me say that I had some expert instruction and supervision and did many dives at 3-4 meters before taking small, slow steps lower. I'm amazed that the lungs can 'squeeze' to 50% residual.

Now comes the hypothetical part. Same diver, mask and sinuses with 10 packs starts down the rope. When does he get to 0.61 litres in the lungs. I figure 6.6, +1.0 pack and the 0.15 for mask ears and sinuses is 7.75 total air, divide by (0.61 plus 0.15)= 10.2 atm or 92 meters (106 without a mask and almost 115 if you equalise with water).

Does anyone agree with the arithmetic? Has anyone measured the 'holes' in the skull? I'll keep working on the three and a half minutes that's required. Does anyone want to buy a pair of liquid goggles, reasonable. At the rate I'm going, I'll be 90 before I need them.

Collapsed Bill
Scuba buddies

Hello Bill,

You have brought up an important issue. Our bodies comprise a system and changes in one part effect the other part. Some of this has to do with fluid transfer.

I have vague recollections of reading about some fluid tranfer studies that were done with scuba diving and I think have become part of technical scuba diving. If I remember correctly this information had to include air space in the head as well. I am sorry that I cannot remember more or be more certain about this.

I wonder if Erik or Cliff could help us out on this.
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Fluid Ventilation

Hi Bill,
Maybe your Total Lung Capacity (TLC) is more. In your experiment, if you exhaled completely, the 5.3 liters are your Vital Capacity (VC) and is 76% (it changes with the age, sex and disease) of your TLC. so the remanider 24% is your residual volume, your TLC=6.97. It's better a body plethysmography for measure of this volumes.
I disagree a little bit with your calcules:
If you start with a total volume of 7.75 liters and want to know at wich depth you reach 0.61 liters, just have to use the Boyle law: P1 x V1=P2 x V2
P1=1 ATA
V1=7.75 liters
V2=0.61 liters

So P2=P1 x V1/V2; P2= 1 ATA x 7.75 liters/0.61 liters=12.7 ATA=117 msw

As you can see, freedivers have gone far beyond, because We have to account the blood-shift, in the calculation of how deep can I freediver goes. I don't remember the exact volume of the "holes in the skull" (sinuses) but it's very low and variable. By the way, what is the price of your liquid goggles?.
About the angus question, I think he refers to fluid ventilation.
The perfluorocarbon is similar to teflon, but it's liquid. You can fill all the air spaces with it (lungs and sinuses) and in that way you can avoid the effects of pressure. And the gas exchange is not affected, this liquid is used also for medical reasons, in patiens with SDRA and Mechanical Ventilation. This is very expensive for sport freedivers, and requires a higly technical structure


Frank Pernett
Aloha Frank

I didn't write that formula in my post. I used slightly different numbers than you did but, the same formula.

"So P2=P1 x V1/V2; P2= 1 ATA x 7.75 liters/0.61 liters=12.7 ATA=117msw "

Off my scratch pad;

P2=P1 x 7.75 (V1)/(0.61 + 0.15)(V2) = 10.2 atm..92 msw. Since the cavities are full at the higher pressure, their volume must be added to V2, I think.

I just tried my first 'water equalisation', with about as much success as my first spearfishing endeavor. That didn't stop me from shooting over 50 White Sea Bass and Black Sea Bass in Calif so, on Sunday I'll try for a 10 meter negative using water up my nose.

Thanks for the reply
Hola Bill,
First, I want to clear that this discussion is theorethical. The formula doesn't predict the depth we can achieve, depending on our TLC.
If you want to account the sinuses volume, remember that they are dead space, that means no gas exchange occurs in their boundaries. You use 0.6 l as the 50% of RV, so you dont have to use the sinuses volume in the calculation, We can't confuse the lung volume with the volume to equalize (you can't equalize your lungs):
P2=7.6 l (w/o mask and sinuses) x 1 ATA/0.6 l= 12.6 ATA=116.6 msw

I don't know if I make my self clear.

I tried once to fill my sinuses with liquid, but I had a bad experience with it.


Frank Pernett
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