bed size mask? possible?

zorrro13 · Post by **zorrro13** » Fri Apr 18, 2008 9:22 pm

Cant get this idea out of my head so here goes.. What about a single bed size pressure chamber. You lay there and wait for your super high speed cpap to pressurise it and then go to sleep. You would need to pee inside as it would take way to long to re pressurise. any thoughts?

Panhandler · Post by **Panhandler** » Fri Apr 18, 2008 9:41 pm

What you're suggesting would pressurize the outside of your chest as well as the entry to your airway, so you'd not get any therapy. CPAP pressurizes the inside of your airway relative to ambient air pressure, thereby "forcing" air through blockages. You need a difference in pressure to have therapy.

I guess it could be done by putting your body in a chamber with your head out and reducing the pressure inside. They used to do that for people paralyzed by polio. The device was called an iron lung, and if you think masks are awkward and uncomfortable....

zorrro13 · Post by **zorrro13** » Fri Apr 18, 2008 9:53 pm

bummer. so back to the face sucker

Snoredog · Post by **Snoredog** » Fri Apr 18, 2008 10:02 pm

didn't Michael Jackson try that?

zorrro13 · Post by **zorrro13** » Fri Apr 18, 2008 10:23 pm

[quote="Panhandler"]What you're suggesting would pressurize the outside of your chest as well as the entry to your airway, so you'd not get any therapy. CPAP pressurizes the inside of your airway relative to ambient air pressure, thereby "forcing" air through blockages. You need a difference in pressure to have therapy.

I guess it could be done by putting your body in a chamber with your head out and reducing the pressure inside. They used to do that for people paralyzed by polio. The device was called an iron lung, and if you think masks are awkward and uncomfortable....

Panhandler · Post by **Panhandler** » Fri Apr 18, 2008 10:55 pm

I think the Jackson chamber is a hyperbaric chamber, and if I understand correctly, the atmosphere inside is pure oxygen (or at least much richer in oxygen than room air.) To overcome apneas, you'll still need more pressure in your airway than surrounding your body.

I wonder, though, if you're in an oxygen-rich atmosphere, if the desaturations from apneas would be significantly less. Maybe someone here has experience with hyperbaric chambers.

k8e · Post by **k8e** » Sat Apr 19, 2008 1:14 am

zorrro13, Thanks for sharing your idea. I love the creative thinking!

split_city · Post by **split_city** » Sat Apr 19, 2008 1:33 am

zorrro13 wrote:
Panhandler wrote:What you're suggesting would pressurize the outside of your chest as well as the entry to your airway, so you'd not get any therapy. CPAP pressurizes the inside of your airway relative to ambient air pressure, thereby "forcing" air through blockages. You need a difference in pressure to have therapy.

I guess it could be done by putting your body in a chamber with your head out and reducing the pressure inside. They used to do that for people paralyzed by polio. The device was called an iron lung, and if you think masks are awkward and uncomfortable....
Just my luck to bump into a rocket scientist first post.. okay genius if i did do the snore dog Jackson chamber thing and I used a cpap and mask at the same time would the pressure need to be reversed?

You actually wouldn't need a CPAP mask at all if you used an iron lung*. The generation of negative pressure inside the iron lung increases lung volume which reduces upper airway collapsibility.

*Note: CPAP may still be required is some people because CPAP also splints open the airway with positive pressure.

Effect of increased lung volume on sleep disordered breathing in patients with sleep apnoea.Heinzer RC, Stanchina ML, Malhotra A, Jordan AS, Patel SR, Lo YL, Wellman A, Schory K, Dover L, White DP.
Sleep Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. rheinzer@post.harvard.edu

BACKGROUND: Previous studies have shown that changes in lung volume influence upper airway size and resistance, particularly in patients with obstructive sleep apnoea (OSA), and that continuous positive airway pressure (CPAP) requirements decrease when the lung volume is increased. We sought to determine the effect of a constant lung volume increase on sleep disordered breathing during non-REM sleep. METHODS: Twelve subjects with OSA were studied during non-REM sleep in a rigid head-out shell equipped with a positive/negative pressure attachment for manipulation of extrathoracic pressure. The increase in lung volume due to CPAP (at a therapeutic level) was determined with four magnetometer coils placed on the chest wall and abdomen. CPAP was then stopped and the subjects were studied for 1 hour in three conditions (in random order): (1) no treatment (baseline); (2) at "CPAP lung volume", with the increased lung volume being reproduced by negative extrathoracic pressure alone (lung volume 1, LV1); and (3) 500 ml above the CPAP lung volume(lung volume 2, LV2). RESULTS: The mean (SE) apnoea/hypopnoea index (AHI) for baseline, LV1, and LV2, respectively, was 62.3 (10.2), 37.2 (5.0), and 31.2 (6.7) events per hour (p = 0.009); the 3% oxygen desaturation index was 43.0 (10.1), 16.1 (5.4), and 12.3 (5.3) events per hour (p = 0.002); and the mean oxygen saturation was 95.4 (0.3)%, 96.0 (0.2)%, 96.3 (0.3)%, respectively (p = 0.001). CONCLUSION: An increase in lung volume causes a substantial decrease in sleep disordered breathing in patients with OSA during non-REM sleep.

Tarma · Post by **Tarma** » Sat Apr 19, 2008 3:30 pm

Not sure, but I don't think an iron lung would help OSA. I don't see where the negative pressure generated by the iron lung would be that much different than the negative pressure generated by your diaphragm. You could still obstruct

As for hyperbaric, I think you would probably still have obstructions, but since your PO2 would be several times normal it would be significant time awhile before you dropped below a "normal" value.

3isles · Post by **3isles** » Sat Apr 19, 2008 4:55 pm

how about something just a little smaller

http://www.starmedspa.com/en/prodotto1. ... ro=2&cod=4

I don't know if its available but you can find links to lots of studies about it and its use with cpap or noninvasive ventilation. I found it a couple of years ago researching alternatives for my dd, but this is a more advanced model than I found then.

zorrro13 · Post by **zorrro13** » Sat Apr 19, 2008 5:27 pm

That is fascinating. Although the model doesn't look to happy about it all
I could use that a couple of times a week. The device not the model..
Actually I could use the m, oh never mind.

RipVW · Post by **RipVW** » Sat Apr 19, 2008 5:27 pm

how about something just a little smaller

http://www.starmedspa.com/en/prodotto1. ... ro=2&cod=4

Now, that's the weirdest thing I've seen in awhile!

sleepycarol · Post by **sleepycarol** » Sat Apr 19, 2008 5:40 pm

Weird!! I have asthma and I hope to heaven I never have to use one of those things!!!

My apap is just fine thank you!!

3isles · Post by **3isles** » Sat Apr 19, 2008 6:40 pm

It is a weird thing, they've got a buck rogers thing goin on

I'll admit its a bit overkill for cpap unless you had just had major facial surgery or something, and I am WAY too claustrophobic to ever use it without major sedation but It would certainly be preferable to intubation or trach for respiratory failure and from what I read it can sometimes help people avoid that. The bed thing reminded me if it.

split_city · Post by **split_city** » Sat Apr 19, 2008 7:11 pm

Tarma wrote:Not sure, but I don't think an iron lung would help OSA. I don't see where the negative pressure generated by the iron lung would be that much different than the negative pressure generated by your diaphragm. You could still obstruct

Tarma, lung volume was increased by an iron lung in the abstract I presented. As you can see, AHI significantly decreased with increasing lung volume. The airway is not exposed to the negative pressure because the head is outside the iron lung. There have been several studies showing that if you increase lung volume, the airway becomes bigger and less collapsible. These differences are present if lung volume is increased by an iron lung, or simply comparing someone at total lung capacity to residual volume (amount of air when you blow as much air out as possibe). The airway also becomes smaller when you move from a seated position to the supine posture. This change is at least partially explained by the fall in lung volume when changing posture.

Here is another study by Heinzer showing that the CPAP requirements to prevent flow limitation was lower when lung volume was increased by an iron lung. This again shows the importance of lung volume on airway patency.

Lung volume and continuous positive airway pressure requirements in obstructive sleep apnea.Heinzer RC, Stanchina ML, Malhotra A, Fogel RB, Patel SR, Jordan AS, Schory K, White DP.
Division of Sleep Medicine, Sleep Disorders Program @ BI, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA. rheinzer@rics.bwh.harvard.edu

Previous studies have demonstrated that lung volume during wakefulness influences upper airway size and resistance, particularly in patients with sleep apnea. We sought to determine the influence of lung volume on the level of continuous positive airway pressure (CPAP) required to prevent flow limitation during non-REM sleep in subjects with sleep apnea. Seventeen subjects (apnea-hypopnea index, 42.6 +/- 6.2 [SEM]) were studied during stable non-REM sleep in a rigid head-out shell equipped with a positive/negative pressure attachment for manipulation of extrathoracic pressure. An epiglottic pressure catheter plus a mask/pneumotachometer were used to assess flow limitation. When lung volume was increased by 1,035 +/- 22 ml, the CPAP level could be decreased from 11.9 +/- 0.7 to 4.8 +/- 0.7 cm H(2)O (p < 0.001) without flow limitation. The decreased CPAP at the same negative extrathoracic pressure yielded a final lung volume increase of 421 +/- 36 ml above the initial value. Conversely, when lung volume was reduced by 732 +/- 74 ml (n = , the CPAP level had to be increased from 11.9 +/- 0.7 to 17.1 +/- 1.0 cm H(2)O (p < 0.001) to prevent flow limitation, with a final lung volume decrease of 567 +/- 78 ml. These results demonstrate that relatively small changes in lung volume have an important effect on the upper airway in subjects with sleep apnea during non-REM sleep.

Just a side note when you said "negative pressure generated by the diaphragm." Many people speculated that it is this negative pressure which collapses the airway. This is in fact probably not the case. I provided data showing the airway tends to collapse towards late-to-end expiration i.e. the airway collapses in a passive manner and not due to negative pressure.

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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, AHI