Lung overexpansion

[eponym]

Probably a silly question but I was wondering. Can you get a lung overexpansion on the surface?

The reason I was wondering is that they say that even very small changes in depth can cause over expansion injury so I was wondering if that small fraction of pressure can be mimicked somehow by our body such as inhaling extremely deeply and hard - if you understand what I mean.

I agree with Boulderjohn - On land, no matter how strongly you inhale, you're just opening your lungs. You can't fill them to more than ambient pressure.

But perhaps the OP wants to know how much diaphragm/ribcage force (against a closed throat) would be necessary to create a voluntary pneumothorax? Is that even possible?

(maybe OP will request a move of this thread to the medical forum)

 

[socc]

I agree with Boulderjohn - On land, no matter how strongly you inhale, you're just opening your lungs. You can't fill them to more than ambient pressure.

But perhaps the OP wants to know how much diaphragm/ribcage force (against a closed throat) would be necessary to create a voluntary pneumothorax? Is that even possible?

(maybe OP will request a move of this thread to the medical forum)

Hi eponym,

Thank you for your reply.
How do I request the movement to the medical forum ?
Yes I was wondering the following:

But perhaps the OP wants to know how much diaphragm/ribcage force (against a closed throat) would be necessary to create a voluntary pneumothorax? Is that even possible?

 

[eponym]

Hi eponym,
Thank you for your reply.
How do I request the movement to the medical forum ?

Understood. I used the "Report Post" (triangle with exclamation mark) object and made the request myself. Some one or another moderator will probably get on it soon.

Best practices always,
Bryan

PS. I've had one adapted (aka disabled) dive student who experienced a spontaneous pneumothorax in his teens. But while I'm aware of major sequelae, I've much less info on what predisposes an individual for the incident.

 

[dumpsterDiver]

I agree with Boulderjohn - On land, no matter how strongly you inhale, you're just opening your lungs. You can't fill them to more than ambient pressure.

But perhaps the OP wants to know how much diaphragm/ribcage force (against a closed throat) would be necessary to create a voluntary pneumothorax? Is that even possible?

(maybe OP will request a move of this thread to the medical forum)

You are absolutely WRONG on this. It is a common technique used by elite freedivers to over fill their lungs. They fill the lungs by a process called packing which involves gulping air using their tongue as a piston. It is not uncommon for this process to result in injuries, particularly to people trying to learn it.

I don't do it. this video at 52 seconds shows the worlds best packing before a record dive,

http://youtu.be/PUcpzf0rbAw

 

[eponym]

You are absolutely WRONG on this. It is a common technique used by elite freedivers to over fill their lungs. They fill the lungs by a process called packing which involves gulping air using their tongue as a piston. It is not uncommon for this process to result in injuries, particularly to people trying to learn it.

Amazing. Thanks for that.

 

[SillyQuestions]

Fill lungs. Close airways. Fall over. Volume of chest cavity decreases, increasing pressure?

Just an idea


Sent from my iPhone using Tapatalk

 

[eponym]

John - thanks for the thread move! That's some quick response time!

 

[TSandM]

You cannot damage your lungs with your glottis open, simply because you cannot generate a pressure greater than atmospheric. With the glottis closed, you can raise your intrathoracic pressure a LOT. Normal lungs will tolerate a significant degree of overpressure, but lungs with areas of pathology will not. Spontaneous pneumothoraces are not uncommonly caused, for example, by powerful coughing paroxysms. But the underlying lung is abnormal.

A high enough pressure, however, will blow holes in normal lung. I have heard a lot of times that surfacing from 4 feet with a closed glottis can result in an air embolism (has been documented to do so) and that corresponds to about a 2 psi increase in pressure, or about 90 torr. I know when our ventilator peak pressures get up over about 40, we start worrying about lung damage.

 

[eponym]

A high enough pressure, however, will blow holes in normal lung. I have heard a lot of times that surfacing from 4 feet with a closed glottis can result in an air embolism (has been documented to do so) and that corresponds to about a 2 psi increase in pressure, or about 90 torr. I know when our ventilator peak pressures get up over about 40, we start worrying about lung damage.

Good information. Can you tell us more?

In what contexts do you measure pressures in torrs? I assume patient monitoring?

 

[drrich2]

A high enough pressure, however, will blow holes in normal lung. I have heard a lot of times that surfacing from 4 feet with a closed glottis can result in an air embolism (has been documented to do so) and that corresponds to about a 2 psi increase in pressure, or about 90 torr. I know when our ventilator peak pressures get up over about 40, we start worrying about lung damage.

Given the extent of our concern over what seem like modest changes in pressure, and with the confession that I'm not in the 'Google & read hunting the answer' mood, any thoughts on what kind of pressure increases we get in our lungs when we have an extended coughing or sneezing fit? Forceful coughing can be painful and I speculate creates a momentary spike in intra-lung air pressure, yet the lay public doesn't generally fear air embolism or pneumothorax from this. I'm not saying it can't happen, but coughing & sneezing are so common I'd think it rare...

Richard.