CR4® - The Engineer's Place for News and Discussion®


Previous in Forum: Fly Killer   Next in Forum: Jumping the Gap of Spinal Cord Injury
Close
Close
Close
23 comments
Participant

Join Date: Oct 2016
Posts: 3

Maximum Pressure for Human Lungs

10/17/2016 10:35 AM

What is the maximum pressure that human lungs can tolerate?

DD 10/17/2016

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
2
Guru

Join Date: Apr 2010
Posts: 5751
Good Answers: 576
#1

Re: Maximum Pressure for Human Lungs

10/17/2016 11:02 AM

It depends on the pressure on the outside of the body. It's the differential pressure that counts. A differential pressure of 1.42 psi is the maximum lungs can withstand, equalivant to about 3 feet of water depth. This is why when divers surface without air tanks they need to breathe out continuously to avoid injury.

http://www.scubaboard.com/community/threads/maximum-lung-pressure.1315/

Register to Reply Good Answer (Score 2)
Participant

Join Date: Oct 2016
Posts: 3
#2

Re: Maximum Pressure for Human Lungs

10/17/2016 11:43 AM

Got it, and it makes sense. Thanks!

Register to Reply
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8399
Good Answers: 771
#3

Re: Maximum Pressure for Human Lungs

10/17/2016 11:45 AM

It will largely depend on the individual.

I can easily hit 2.5 - 3 PSI on a small 0 - 10 PSI digital gauge set I have.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#4
In reply to #3

Re: Maximum Pressure for Human Lungs

10/17/2016 1:12 PM

Blowhards would be considered to be out on the far right of the bell curve, not the diving bell.

Way to go! That really is something you could brag about, though.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Oct 2008
Posts: 39892
Good Answers: 1588
#5

Re: Maximum Pressure for Human Lungs

10/17/2016 2:54 PM

Internal, or external?

Register to Reply
Participant

Join Date: Oct 2016
Posts: 3
#6
In reply to #5

Re: Maximum Pressure for Human Lungs

10/17/2016 3:20 PM

Internal, relative to ambient (nominal 14.7psi).

I.E. a safe pressure for inflating a collapsed lung is ≤ x psi.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#7
In reply to #6

Re: Maximum Pressure for Human Lungs

10/17/2016 3:52 PM

Usually, pressure internal to the collapsed lung is not the problem. It is all the blood around it, inside the membrane that does not allow the lung to fill with air.

The S.O.P. is to puncture the membrane with a tube inserted to relieve the fluid pressure around the lung, and allow lung to begin filling again. If the lung is actually punctured, then a surgical repair is in order and is an emergency procedure to save the patient's life.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Oct 2009
Posts: 1197
Good Answers: 23
#13
In reply to #7

Re: Maximum Pressure for Human Lungs

10/18/2016 9:42 AM

Almost right. Certainly any air or fluid in the pleural cavity (that space between the lung and the chest wall) needs to be drained out through a chest tube to allow the lung to expand. This is a more sensible procedure than trying to inflate the collapsed lung from the inside. However, even if the lung itself is punctured it is not always necessary to proceed to surgery. A small negative pressure in the chest tube may suffice to hold the lung against the chest wall and thereby to seal the leak.

Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#16
In reply to #13

Re: Maximum Pressure for Human Lungs

10/19/2016 9:16 AM

Thank for for the clarification, as I am certainly no physician. I did stay at a Holiday Inn once, so I am qualified in conjecture.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Oct 2008
Posts: 39892
Good Answers: 1588
#8
In reply to #6

Re: Maximum Pressure for Human Lungs

10/17/2016 5:24 PM

What James Stewart just said.

This is no job for a bicycle pump, even in an emergency.

Register to Reply
Member

Join Date: Apr 2011
Posts: 7
#9

Re: Maximum Pressure for Human Lungs

10/17/2016 11:39 PM

I recall a keen athlete who used to to do body building and other exercises - he used to blow or inflate hot water bottles by his breath or lung pressure. Hot water bottle is at least a millimeter thick plastic - I have no idea what pressure is required but this link may help.http://sploid.gizmodo.com/man-with-incredibly-huge-lungs-can-make-a-hot-water-bot-1618031822

Register to Reply
Power-User

Join Date: Nov 2015
Posts: 335
#10

Re: Maximum Pressure for Human Lungs

10/18/2016 2:25 AM

Some think, they can just get away and blow lungs in a ventilator unnoticed as though there are no eyes watching. They really hope there is none watching, as though life is an accounted, but its POD for sure. Now, they laugh for a piece of little time and a little later they die for eternity.

__________________
"And ye shall seek me, and find me, when ye shall search for me with all your heart."
Register to Reply Score 2 for Off Topic
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#15
In reply to #10

Re: Maximum Pressure for Human Lungs

10/19/2016 9:14 AM

What the ____ are you talking about? POD? Go read Proverbs, especially the part where it is good for man to work, rest, drink his beer, or wine, and not concern himself with deep mysteries for a time. Worship God, but do not judge man, you do not have the insight, the authority, nor the patience for that, only God can do God's job.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
5
Guru

Join Date: Oct 2009
Posts: 1197
Good Answers: 23
#11

Re: Maximum Pressure for Human Lungs

10/18/2016 9:19 AM

The physiology of the lungs being formerly one of my specialties, I have done a literature search. In this paper the maximum expiratory pressure (the sort of pressure generated in coughing) which a healthy adult male could generate averaged 194 cm H2O (almost 2.8 psi). This is measured against surrounding atmosphere.

With diseased lungs it is a different matter. When embarking on mechanical ventilation it would be considered bad practice to use more than 30 cm H2O inflation pressures, for fear of causing further lung damage.

Register to Reply Good Answer (Score 5)
Guru

Join Date: Oct 2008
Posts: 39892
Good Answers: 1588
#12
In reply to #11

Re: Maximum Pressure for Human Lungs

10/18/2016 9:25 AM

I knew there was a doctor in the house.

More than one, actually.

Register to Reply
Guru
Hobbies - DIY Welding - Don't Know What Made The Old Title Attractive... Popular Science - Weaponology - New Member United States - US - Statue of Liberty - 60 Year Member

Join Date: Apr 2009
Location: A ways down the street from Glacier National Park
Posts: 6374
Good Answers: 265
#14

Re: Maximum Pressure for Human Lungs

10/18/2016 3:39 PM

We had a discussion about this a while ago:

http://cr4.globalspec.com/thread/79066/Human-Lung-Air-Pressure

However, a definitive answer seems to have been given by phph001. I don't know about anyone else, but I'm throwing him a GA.

__________________
“If you think education is expensive, try ignorance.” Andy McIntyre
Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain, and now disconnecting as Little England and Wales (not too sure about Wales bit, either). Kettle's on.
Posts: 26709
Good Answers: 700
#17

Re: Maximum Pressure for Human Lungs

10/19/2016 4:42 PM

Some research into deep sea diving is appropriate....

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru

Join Date: Apr 2011
Posts: 6554
Good Answers: 241
#18

Re: Maximum Pressure for Human Lungs

10/24/2016 3:02 PM

For abrupt overpressure, as in a shockwave from an explosion...

'....The threshold for lung damage occurs at about 15 psi blast overpressure. A 35-45 psi

overpressure may cause 1% fatalities, and 55 to 65 psi overpressure may cause 99%

fatalities. (Glasstone and Dolan, 1977; TM 5-1300, 1990)....'

For the threshold for an aim embolism from excess pressure in lungs relative to outside body, as in forgetting to exhale while ascending having inhaled to capacity at greater depth on SCUBA.... the threshold can be pretty low, probably well under 10 psi, and likely less than the pressure one might developed to blow up a heavy balloon.

.

For maximum pressure when equalized with ambient:

...breathing normal air, 20 atmospheres would incapacitate very rapidly and death would be likely without immediate assistance and facilities for recovery

....taking significant precautions and special breathing atmospheres, numerous people have survived moderate periods at pressures around 30 atmospheres. 40 atmospheres would present significant problems with getting enough O2 but avoiding O2 lung toxicity due to high partial pressure.

__________________
Eternal vigilance is the price of knowledge. - George Santayana
Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#19
In reply to #18

Re: Maximum Pressure for Human Lungs

10/25/2016 9:14 AM

Aren't we simply talking about imploding or being crushed to death at those high pressures?

That seems ridiculously high. If that is external pressure, with ambient pressure in the lungs initially, the compression would crush a human body, I suspect.

If you are speaking of inflating lungs to such pressures, and having ambient 1 atmosphere pressure externally, I could not imagine the human body withstanding such internal pressure. CNS toxicity really, when the lungs would simply explode?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Oct 2009
Posts: 1197
Good Answers: 23
#20
In reply to #19

Re: Maximum Pressure for Human Lungs

10/25/2016 2:05 PM

No, the chart has partial pressures of oxygen on the Y axis. Obviously you cannot have a partial pressure of >1 atmosphere unless the environment itself is at a higher total pressure, so the diagram relates to the situations of diving or hyperbaric chambers. I can confirm that we would use the data in this diagram in the management of patients in intensive care. Specifically we would not run 100% oxygen (1 atm at sea level) for 24 hours in patients with lung damage, as this causes irreversible further damage. The danger that a patient receiving high oxygen percentages in a hyperbaric chamber might suffer a seizure is well known.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#21
In reply to #20

Re: Maximum Pressure for Human Lungs

10/25/2016 2:13 PM

How are you ready the Y -axis again? Is that the partial pressure in atm? Really?

OR is that factored where 1 = normal atmospheric breathing, and 2 is twice total atmosphere?

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Guru

Join Date: Oct 2009
Posts: 1197
Good Answers: 23
#22
In reply to #21

Re: Maximum Pressure for Human Lungs

10/26/2016 9:04 AM

The chart is clearly labelled on the Y axis "INSPIRED OXYGEN PRESSURE, Atmospheres". This means it relates specifically to the oxygen pressure, i.e. the partial pressure. There could also be nitrogen in the mixture. If the ambient pressure is 1 atm then 1 atm of oxygen is 100% of the inspired gas picture. If the ambient is 2 atm then the percentage of oxygen is only 50%. The point is that the damage to the body relates not to the percentage but to the absolute pressure of oxygen.

Register to Reply
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 13508
Good Answers: 152
#23
In reply to #22

Re: Maximum Pressure for Human Lungs

10/26/2016 10:24 AM

OK, not planning on being in a hyperbaric chamber any time soon, or inflicting that on anyone, but knowledge is worth getting it right.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Register to Reply 23 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

davinderdhanjal (1); ddurgin (2); Doorman (1); James Stewart (7); lyn (3); Mr. small (1); phph001 (4); PWSlack (1); Rixter (1); tcmtech (1); truth is not a compromise (1)

Previous in Forum: Fly Killer   Next in Forum: Jumping the Gap of Spinal Cord Injury

Advertisement