Experience with Provent?

[Galactus]

I just reread your post and I think I know where you are losing the point. Your post about the breathing is not the issue. I believe what you are missing is the reason your airway is collapsing. Your airway isn't collapsing because of the negative pressure breathing in. Your airway is collapsing due to muscle relaxation. The propping open of the airway is being done by keeping pressure in the airway. During the breathing cycle when you exhale, at the end of the exhale is where you experience the lowest point of pressure inside the airway, and that is when it collapses. If there was pressure inside the airway at this point it would be less likely to collapse. Provent makes that pressure by not allowing a complete exhale.

In regards to breathing in exhaled gas, it is not likely to create anymore rebreathing than you experience now with a mask, not at all like a paper bag where you are just breathing and rebreathing the same as you point out a bad idea.

Oh and just a note about text size, I didn't take anything you said personally, so no reason to worry about offending me at all, I rarely get offended. Besides, I told you in another thread, people tell me I'm a jerk all the time, you disagreed then..... now you tell me I'm not a Roaades scholar!! Well thank heavens I ain't building no highways (pun intended) (just in case)

[AshSF]

From whatever little I have read in the last 4months, EPAP is needed for eliminating Obstructives. And IPAP is needed to eliminate Hypopneas and for ASV purposes. Dr. Barry Krakow is a big fan of BiPAPs for this reason. So potentially, Provent's EPAP may eliminate obstructive apneas and provide relief.

I asked my sleep doctor and he said that for me (untreated AHI of 77), it won't work.

We need Vsheline or DocWils to interject here. They understands Ventilation much better than I do.

[DocWils]

I have already weighed in on this elsewhere on this forum. For reasons I will not go into, I will not weigh in again on this product.

[Galactus]

From whatever little I have read in the last 4months, EPAP is needed for eliminating Obstructives. And IPAP is needed to eliminate Hypopneas and for ASV purposes. Dr. Barry Krakow is a big fan of BiPAPs for this reason. So potentially, Provent's EPAP may eliminate obstructive apneas and provide relief.

I asked my sleep doctor and he said that for me (untreated AHI of 77), it won't work.

We need Vsheline or DocWils to interject here. They understands Ventilation much better than I do.

I like that idea, I made the call, we shall see who answers

[Galactus]

I have already weighed in on this elsewhere on this forum. For reasons I will not go into, I will not weigh in again on this product.

Can you at least link us to your post on that as I do not believe I have seen them. Thank you in advance.

[DocWils]

Essentially, it pointed out the testing methods for Provent seemed flawed, early results from local trials shown to me indicated that except for people with a low SA rating it would be ineffective or of limited effect, and after some give and take I opined that as a full on therapy method it would not replace CPAP, but it might be useful for vacations or other short term uses for some patients, but not for those who have shown severe AHI prior to treatment. This was then backed up by a patient from the UK trials, who confirmed the flawed method for testing in the trial he participated in. In the initial US 3 month trials the authors claimed a 40 percent reduction for patients with an AHI of 14 or so to 6 (a relatively mild apnoea) out of a median AHI over the entire study group of 12, compared to the 10 percent reduction on the placebo devices. That there could be any reduction on a placebo device is to me already curious and a little alarming. In a later follow up study, published in Journal Clinical of Sleep Medicine, the authors cherry picked the the 34 most compliant patients from the 127 patients of the the initial 3 month study, which skewed the data further. There the sustained improvement was said to be from 16 to 5 in median AHI. Given that many on this forum have AHI in the 30 and above range before treatment, the question of if this could be useful for forum members is a bit doubtful. Disclosure: Both studies were funded by Ventus Medical, partially conducted at private sleep centers, and all three authors report receiving financial payments from Ventus Medical. There is no data on cardiovascular outcomes from the use of Provent from these studies, so no conclusion can be drawn on that.

Since I was basing my initial opinion on raw data from a local study while the study was still in progress, and not the final data, I cannot comment further as to the eventual results of the study, which were not given to me, but I can say that in the data I did see, non placebo patients did not fare significantly better than placebo patients if they had started out with high AHI levels - this is to be seen in the light that "significant" would mean a large reduction to near sub clinical levels, which was never achieved in patients with high AHI, although low AHI patients did have reductions to or near sub-clinical levels in some cases. I did opine that data published by Provent seemed cherry-picked to emphasise the latter group's results, and the selection of patients weighted in favour of supporting their claims. However I stress that that is my opinion and not a proven fact. Provent was and is welcome at any time to make all raw data from the studies available for independent perusal at any time for a better opinion. Or better yet, to make production devices available for better controlled study after a fashion I shall discuss briefly further on. I should point out that all of the studies I had seen, independent of the raw data I mentioned from the local study, were funded by the people who made Provent. Independent studies may exist, but I had not seen details on such studies at the time of my posting. It is not known to me if the study leader in the local study received financial consideration from Ventus Medical.

I questioned the need for placebo patients in such a study, as there is no psychosomatic effect in SA at all, so far as we can see - the problem is mechanical and cannot be influenced by attitude or belief. As such, any reduction in AHI by a placebo device warrants further study and a close examination of the nature of the placebo device. While the study was called a double-blind study, one patient witnessed a phone call from the UK study to the study director in Zurich who decided which group the patient should belong to, thus violating the nature of a double blind study completely and invalidating that particular result.

My posting the above on this forum resulted in some trouble for me, and as such I prefer not to go into any greater detail on the efficacy Provent, save to say that I am of the opinion that if it works for long term treatment, it works on patients that are just above clinical levels of SA and not on those who's AHI rises to a level that many on the forum have. I cannot comment on whether it would be more effective for OA patients than CA patients - the scope of the Provent testing and their own marketing does not allow for that distinction to be made. However, Provent and EPAP as a whole is thought to be for OSA rather than CA.

There is an over the counter version called Theravent.

As to how EPAP works, it is to be noted that upper airway collapse has its origins at the end of expiration, when the pressure in the airway is at or near zero. It has been demonstrated that the upper airway cross sectional area progressively decreases in the four breaths prior to an obstructive apnea, with this area being smallest at the end of expiration, and as such creates a collapse at the next in-breath. EPAP is thought to create increased expiratory pressures which are maintained through the end of expiration and until the start of the subsequent inspiration, thus maintaining enough positive pressure to prevent collapse. However, the exact mechanism of how this might work is unclear, although several theories are prevalent. It is also important to note that patients who are CPAP compliant consistently, in studies, do far better with CPAP than with EPAP and achieve better relief of symptom. It may be that EPAP strips such as Provent or Theravent might be useful for non CPAP compliant patients, but I rather suspect that it would be better to use them to train such patients up to CPAP, as it is proven far more effective, and year on year use of EPAP strips is still not proven as clinically effective. It is also to be noted that in all trials, evaluation of effectiveness was made using in-lab PSG (polysomnography) rather than nightly home monitoring using recording pulse oxymeters. As such, there is no overall record of each nightly level of sO2sat desaturations to measure the actual effectiveness of nightly use. Instead the methods used for evaluation provide a limited picture rather than a fluid one and may skew the data set. Since wrist recording pulse oxymeters are comfortable and relatively inexpensive for the purposes of such testing, and the simplest way to gather effective data for the determination of apnoea events via sO2sat levels, I find the results to be at best relative and not conclusive. The use of placebo devices and flawed single and double blind studies to me obfuscates the possible results and is, in this sort of treatment, a magician's trick of misdirection, as it actually focuses the attention away from total efficacy sampling when larger samples using the entire test group would have provided a more complete picture.

Nightly EKG and EEG testing is not needed, but certainly the easiest and simplest method to measure the effectiveness remains sO2sat levels over the course of a night, something each of these studies could have done. The devices are cheap and easy for the patient to use and gather the data on their computers to either e-mail in or bring in at the end of the run for evaluation, and software exists to quickly scan such results and build a picture of the entire test run, which when combined with spot checked PSG would give a better and more complete picture. As it is, each study relied on no more than a few PSGs, one before, one during and one at end of study to build their picture of the effectiveness of treatment and in some studies the odd PSG in between. Experienced CPAPers can readily attest to how incomplete such a picture would be, given the wide variance of AHI levels most CPAPers experience over the course of three months under treatment. In such a study, the simple criterion would be: desat to 88% or below = SA, stable sO2sat levels in acceptable parameters (91-98%) indicates effectiveness of treatment. There is no need to measure snore levels or sleep quality levels other than in spot checks, although snore levels are easy to monitor nightly at home. iPhones can do it these days.

So, that is it in a nutshell. Draw what conclusions you will from it. I make the opinion that it may be effective in some cases, there is no strong evidence for long term use safety or effectiveness in more severe OSA cases, and none for complex apnoea, and if you are given a choice between CPAP and EPAP, and can comply with CPAP (which is increasingly easy as machines get quieter and masks get more comfortable), choose CPAP and save EPAP for vacations. Also, consider the cost - at (at the time of Provent's original market roll-out) $75 per month, over a 5 year period it quickly overtakes and exceed CPAP in cost and was not at that time covered by insurance plans. I do not know if it is now.

[Galactus]

Hey Doc,

Thanks for replying, and for the information, hope I didn't cause you too much trouble.

Thanks for the info on Theravent as well. I just took a quick look at their website, and was surprised to see they in fact offered free samples.

I don't think this would work for me based on my case, but it will be interesting to see how they feel and work just for giggles if nothing else.

Thanks again!

[Jim Bronson]

Theravent offers free samples, but they enroll you in their "Loyalty Club". They will continue to send you monthly supplies of the product and charge your credit card. This is fine if the product works, but some scam companies make it almost impossible to get out of the "club". Victims wind up getting copious supplies of widgets that don't work and get charged for them, along with unreasonable S&H costs. I'm not saying that's what Theravent does, but that ploy is very common, and the fact they offer it sends up a red flag to me. Be careful! Sometimes it is very expensive to get something for free.

[archangle]

The way it works is to create pressure in the airway, whether during inhalation or exhalation it accomplishes the same thing, to keep the airway pressurized thereby not allowing it to collapse. Think of it this way, it doesn't matter how you pressurize the straw or from which direction, just so long as it remains pressurized. I am not saying they work I am just saying that is what they are purported to do.

Provent simply can't create positive pressure in the airway during inhale. If the pressure in the airway isn't lower than the room air, the airflow will be out, not in. The air isn't going to "swim upstream" without some sort of fan.

i.e. the pressure in your airway goes to zero or negative when you inhale with provent.

Or, equivalently, inhale doesn't start until your airway pressure becomes negative.

[DocWils]

Archangle, see my above posting as to how airway collapse works, third last paragraph.

G, I will only know if this reopens "old wounds" over the next few weeks, but hopefully no big problems should come my way - it did create some back then, though, and I had a lot of politics to deal with, and sore feelings from colleagues (thankfully in a different building on the campus than where I work, but it had fallout with my bosses as well, and for a while I seriously considered accepting a post at another facility).

One more thing for all to note - the aim of CPAP therapy is to reduce the overall AHI to below 5, which is defined as the clinical border line for this problem. Consistent AHI above 5 may still have long term health effects. As such, if the Provent or Theravent devices do not lower your AHI to below 5 for long term use, and few studies indicated that they did except in the milder cases of SA, then the long term health benefits are far less than CPAP or the equivalent, although, for those who are non-compliant on CPAP, anything long term is better than nothing long term, I suppose. I will also note that if you can get used to Provent or Theravent, which feels something like having your nose pinched shut when trying to breath out, you can get used to CPAP and a nasal pillow, and as such, the best worth I can imagine for these strips is to train you up to accept a CPAP device if you are initially non-compliant, and as a quick and dirty device for vacation or other travel situations, or when you just need an emotional break from CPAP. I will also note that those who require a full face mask in order for CPAP to be useful to them cannot under any circumstance gain significant benefit from these nasal strips - only those who can use nasal pillows or nasal masks need even bother considering it.

I will also note that when I made a few random enquiries of American colleagues who prescribed Provent when it rolled out, almost all told me that the results were decidedly mixed, with many patients actually showing no benefit or even worsening results, and only mild cases showing any real clinical benefit. As such, there was no anecdotal evidence from my enquiries to support the studies as published by Ventus Medical. However, anecdotal evidence is not admissible in scientific studies. These were informal findings I gathered from practising doctors in real world situations rather than lab or test situations and cannot be considered formal or conclusive. And yes, I am being very careful in my wording and disclaimers.

At no point could I obtain a sample kit to test on myself, using criteria that I would find acceptable (noting that I have access to all needed testing devices at all time - I own most of the necessary kit already, the rest I could obtain from my work) and would have (and still would) happily welcomed the opportunity to do so. Therefore I cannot evaluate the effectiveness on a "typical" obstructive sleep apnoea patient in a real world environment by a trained observer. As such, I will reserve judgement.