December 22, 2017
If you’ve read about my sleep study experience, you know that I’ve spent thousands of dollars on sleep testing and thousands more on a state-of-the-art Positive Airway Pressure (PAP) machine. My intention was, and still is, to use the PAP machine so I’m not choking throughout the night while experimenting with other approaches that will hopefully fix the underlying problem.
In the last article, Sleep Testing – DIY, I wrote about how for a fraction of the cost and without leaving the comforts of home, a person can test their own sleep quality. In this article, I’m going to describe my experience using different PAP machines including how I discovered that a $150 dollar PAP machine worked best for me.
Now before you click away thinking you don’t have a sleep breathing issue, please be advised that 37% of men and 50% of women are being mildly suffocated in their sleep. My guess is that for those with CIRS, the percentages are even higher. I’d strongly advise testing and treated sleep disordered breathing. It’s important to care for the body.
On the other hand, if you’re thinking that there is no way you’re going to be able to tolerate wearing a mask at night, that’s partly why I wrote this article. What I discovered is by understanding how PAP machines work and having a Do-It-Yourself (DIY) method of testing your sleep, that it’s possible to tweak machine settings and make the PAP experience positive. Once PAP is in place preventing a person from choking in their sleep, I’m all for looking into other sleep breathing treatments.
A Rough Start
When I got home from the somewhat grueling sleep studies and more than a few pennies lighter, I had to work with my supportive local doctor to obtain a prescription for PAP equipment. The sleep center I went to was out of state so although they provided thorough all reports and recommendations, they couldn’t actually write a script for me. In response, I organized all the results, highlighted the findings and recommendations, and included a succinct cover letter to my local doctor asking if it would be possible to get a prescription. It worked.
Script in hand, I then needed to purchase a machine. The prices being quoted at various PAP suppliers was over $4,000! That’s crazy. Eventually, I started digging through the forums on the Apnea Board and found a wealth of information that included directions on how to get into all of the settings on any machine, where to shop for equipment, and lots of seasoned advise on to setting up a machine and making the experience comfortable. I purchased my first PAP machine, the Dreamstation BiPAP Auto SV, for around $2,500.
Finally, months after first discovering my upper airway was blocked off during sleep, my new Dreamstation arrived. Finally, I was going to give my body the air it needed to heal through the night. Having the Clinician Manual in hand that I got from the Apnea Board, I carefully adjusted all the settings that included the pressure recommendations from the sleep clinic.
That night I slept like crap. The machine I purchased is very sophisticated and is capable of addressing irregular breathing patterns, apneas (when you stop breathing), and obstructed airways (RERA). In my case, I only have issues with an obstructed airway – my big tongue drops back and my airway narrows while I’m sleeping. As such, technically I didn’t need this complex of a machine. However, in reading over the very terse manufacturer descriptions as to the differences between machines, I decided on this Adaptive Servo (ASV) PAP machine. More adaptive is better, right?
Manufacturer literature states that these machines monitor breathing on a breath-by-breath basis and make pressure adjustments from moment to moment. This sounded good because I wanted a machine that would provide the least amount of support in a way that was as natural as possible. Below is a summary of my understanding at the time I bought the machine. I wanted the machine to “follow my lead”. On the Apnea Board, I wrote in a post called ASV Versus Other PAP Machines.
When it comes to treating disordered breathing due to sleep obstructions with PAP therapy, the basic approach is to pressurize the entire oral and chest cavity with enough air so as to hold open that portion of the airway that otherwise collapses. In essence, PAP machines blow the airway up like a balloon. Personally, it’s hard for me to imagine there aren’t long-term health consequences to this for a certain percentage. The fact that I’ve read reports that some have dramatic increases in central apneas with CPAP and even Bi-level machines suggests that the body isn’t entirely happy with the process; the human body is exquisitely interconnected and complex. Granted, PAP therapy is one of the better solutions when sleep disordered breathing is present, but I really do wonder about the use of less adaptive PAP machines – like CPAP.
When it comes to treating disordered breathing due to an obstruction that completely closes off the airway as in Obstructive Sleep Apnea (OSA), or due to a restriction as in Respiratory Effort Related Arousals (RERA), the basic approach is to blow up the airway using PAP therapy. The inexpensive approach to this that the insurance industry promotes is to apply one constant and relatively high pressure (ie CPAP). Generally, only if a person has problems, like increased central apneas where they stop breathing, are more adaptive machines made available that better mimic natural breathing. In the case of BiPAP (Bi-level), the machine has the ability to vary the inspiratory pressure in rhythm with the body while also keeping pressures high enough to keep the airway open.
From what I can glean, there are lots of other features like being able to change the Breaths Per Minute (BPM), Rise Time (RT), and Inspiration Time (IT) on each of the main types of machines that often allow each basic machine type to come close to operating like its more adaptive successor. This isn’t totally clear to me yet as there is a lot of jargon to learn and machine designations are utterly confusing. Still, it seems that a good quality machine of whatever type tends to have quite a few settings and the ability to capture data that can be read by the user in order to adjust their particular machine. Given the fact that conventional medicine essentially left me for dead, I’m totally into being able to adjust my machine and take control of my own health.
When it comes to ASV, the defining difference seems to be that the machine also has the unique ability to vary pressures based upon the tidal volume (total amount of air delivered) in concert with what the body is naturally doing. When I tried BiPAP, there was a more forced element to it; it felt like I was being expanded too much with each breath. Within a few breaths on ASV, the fact that the machine regulates pressures based upon the average volume of air a person inhales was really apparent and felt way better.
I’ve read that the downside of ASV is that it will really crank up Pressure Support (the difference between inhalation and exhalation pressures) very rapidly when it senses an excessive drop in tidal volume (TV). Not surprising, this can wake some folks up. Given that I mostly suffer from RERA types of disordered breathing (sucking air through a straw all night), I don’t tend to have the waxing and waning of breath volume that people with Cheyne-Stokes and other breathing disorders have. As such, I don’t think ASV was altering Pressure Support (PS) much as I slept when I was tested at the sleep clinic; I’m a very light sleeper and think I would have woken up.
If rapid changes in both exhalation pressure (EPAP) and Pressure Support (PS) wakes a person up too much, and they don’t have some complex mix of sleep apnea that demands the use of ASV, BiPAP seems like the way to go. Like ASV, BiPAP has the ability to address obstructed and restricted breathing along with central apneas (when the brain stops sending the signal to breath). Auto BiPAP does this by being able to vary the inhalation pressure over a fairly wide range while having fixed exhalation pressure (Auto BiPAP does not have variable exhalation pressure like ASV). In addition, Auto BiPAP makes these pressure adjustments more slowly while still working to induce breathing during central apneas by increasing the difference between the inhalation pressure (IPAP) and exhalation pressure (EPAP) – the Pressure Support (PS). CPAP and its variants can not treat central apneas.
In terms of the better ResMed ASV or Respironics (Dreamstation) ASV machines, it appears that the Dreamstation has a lot more settings that a person can change; ResMed is mostly auto adjusting. With this in mind, the other main complaint with ASV (besides the rapid PS changes) is that it will force a breath while you’re still awake and naturally stop breathing because you’re maybe focusing on something. Given that central apneas really aren’t my issue, I’m seriously thinking about getting the Dreamstation where I can turn the Breaths Per Minute rate way down and thereby eliminate the forced breath issue.
When I reread this comment, I had quite a bit right but was missing some important nuances that make all the difference in terms of comfort. In addition, I didn’t have any first hand experience using the machine for any length of time so I didn’t really understand some of the settings like Backup Breath Rate. Most importantly, I thought that the reason I liked the ASV machine I tried at the sleep clinic better than a bi-level machine was because the ASV was monitoring my “tidal volume”, the volume of each breath, and adjusting the pressure settings to match. I was way off on that point; they just didn’t have the bi-level machine set up very well. Ugh.
Bi-Level PAP Therapy
As it turns out, after many weeks of tweaking the settings on my expensive Dreamstation ASV machine, I have effectively turned off all of the auto-adjusting functionality and dropped the pressures way down. With the original settings and auto-adjusting feature enabled, it was impossible to sleep with the machine. As a consequence, I needed to start tweaking settings. I thought to myself that even if I lowered the pressures, so I could tolerate the therapy, that some support was better than none.
By the time I got done, I’d effectively turned my expensive, auto-adjusting ASV machine into a standard Bi-level (also called Bi-PAP and BPAP) machine. To confirm this, and also to have a backup unit on hand, I purchased an inexpensive, used Bi-level machine for around $150. Sure enough, the felt experience of my expensive “throttled back” Dreamstation and the used Bi-level machine were essentially the same.
To begin to explain how I ended up at Bi-level therapy, I need to take a few minutes to describe the felt experience of different types of PAP machines. Before I dive in, please go to PAP Machines and read about the differences between CPAP, APAP, BPAP, ABPAP, and ASV machines. This will help with what follows.
The Bi-level machine I bought is a used Resmed S9 VPAP (S) machine. This Bi-level machine cost $150. That’s $2,350 less than my expensive ASV machine! If you read PAP Machines, you know that this machine has fixed inspiration (IPAP) and expiration (EPAP) pressure settings along with several “comfort” settings that I’ll get into in the next section. The inhalation pressure (IPAP) is typically set about 4 cm of H2O higher than the exhalation pressure (EPAP).
While we’re on the topic of the Resmed S9 VPAP, this bi-level machine comes in three different models. There is the standard (S) model that is as I’ve just described. There is the (ST) model that has the additionally ability to artificially stimulate breathing in folks that stop breathing all together (apnea). Upon sensing that breathing has stopped, the ST model alternately applies fairly high inhalation pressure (IPAP) followed by fairly low exhalation pressure (EPAP) at some pre-set Breaths-per-Minute (BPM) rate. In so doing, breathing continues even though the brain has temporarily stopped sending a signal to breath.
The (Auto) model of the Resmed S9 VPAP has the ability to vary the inhalation pressure (IPAP) while the exhalation pressure (EPAP) is fixed – both EPAP and IPAP pressures are fixed on the other two models. This is done through three settings. First, there is the constant exhalation pressure (EPAP) setting. Second, instead of an inhalation pressure setting, there are maximum and minimum Pressure Support (PS) settings. Pressure Support (PS) is the additional pressure added to the EPAP pressure to arrive at the inhalation pressure (IPAP). For example, if EPAP is 8 cm of H2O and PS is 4 cm of H2O, then the minimum IPAP pressure is 8+4=12 cm of water. However, unlike the other models, the machine may increase the IPAP pressure by increasing the pressure support (PS) up to the maximum PS setting entered into the machine. This may be as high as 25 cm of H2O.
In other words, let’s say a person is breathing fairly well on their side, the machine senses this an uses the gentler EPAP pressure of 8 cm of H2O with a PS of 4 cm of H2O making the IPAP pressure 12 (4+8). Later on, when the person rolls onto their back and their airway closes, the Auto model will increase the pressure support (PS) up to either the maximum PS setting, or the maximum set IPAP setting, in an attempt to open up the airway. When this happens EPAP remains at 8 cm of H2O but IPAP may rise as high as 25 cm of H2O depending on the settings.
In fact, I purchased a machine even more adaptive than the Bi-PAP Auto version called Adaptive Servo Ventilator (ASV) machine. In addition to being able to vary the inhalation pressure (IPAP) over a range, it can also vary the exhalation pressure (EPAP) over a range. Furthermore, this machine monitors the “tidal volume” of each breath and adjusts its pressures accordingly. If you start taking little sips of air instead of normal breaths, the machine will notice this more quickly and will increase EPAP, IPAP, or both in a way to try and instill your typical breath volume.
Based upon what I’d read, my thinking was that the more adaptive a PAP machine was, the more comfortable it would be. I thought that instead of having to use a higher constant EPAP pressure that the EPAP pressure could be lower on the more sophisticated machines. I thought it the baseline pressures would be lower because these machines are capable of increasing pressures as needed. Given that I suffer from obstructed breathing, I didn’t expect the machine to be increasing pressures much over the lower baseline values.
In practice and getting back to why I tweaked my ASV machine so heavily, it turns out that the auto-adjusting machines can be a real nuance. What I mean by this is that by design they are constantly monitoring your breath and adjusting pressures. If you’re sleeping, your breath is much more regular and very few pressure adjustments are made. However, if you wake up and roll over like I often do and you don’t continue to breathe regularly, the machine thinks you’re getting into trouble and starts jacking up pressures. The trouble is that these pressures can be quite high and don’t back dpwm for quite a while. I found myself gingerly rolling over while continuing to breathe smoothly in an attempt to not trigger an automatic pressure increase – I tend to hold my breath as I work to roll over under my heavy bedding.
If my breathing became irregular while rolling over, the EPAP and PS values would quickly climb. Experientially, a higher overall exhalation pressure (EPAP) isn’t that hard to ignore. However, I found the increases in pressure support (PS) to be intolerable. Remember, PS is the amount of additional pressure applied to the lower EPAP pressure to come up with the higher IPAP inhalation pressure. PS represents the pressure swings from low to high. (EPAP + PS = IPAP)
So here’s the best way I can think of to explain the felt experience of mask pressure and why I found higher pressure support (PS) levels intolerable. Let’s start with the decrepit CPAP machines. CPAP applies one high pressure all the time. The pressure is generally set rather high because there needs to be enough pressure to keep the airway open after you’ve been out drinking all night and you’re lying on your back with your airway seriously closing off – alcohol relaxes the airway.
With CPAP and its cousin APAP, every time you go to inhale, high pressure air fills your lungs while the pressure around your body remains the same. The net effect is that you easily take in a big gulp of air. That air equalizes somewhat with the lower surrounding pressure so when you go to exhale, breathing out against the higher pressure takes even more effort as you have to build up enough pressure with your lungs to overcome the machine pressure. Many find this uncomfortable.
When CPAP pressures are very low (4 cm of H2O), the increased volume of air on the in-breath feels quite nice and having to breathe out isn’t troubling. However, CPAP and APAP pressures are generally set much higher. With higher pressures, when you go to inhale, it feels like you’re being filled up like a balloon (and you are). When you go to exhale, it can be very uncomfortable having to work to get rid of a breath of air – not to mention the fact that a person tends to blow off too much CO2 that then induces central apneas in some.
Now I know I just said two paragraphs ago that an increase in constant overall pressure was easy to ignore. It is when we’re talking about Bi-PAP machines that apply a constant lower exhalation pressure (EPAP) and then increase this to a higher (IPAP) that I was referring to. Basically, the additional IPAP pressure that fills your lungs gives you the extra force you need to effortlessly breathe out against the lower EPAP pressure. It’s a nice innovation.
So getting back to my issue of pressure support (PS), as PS increases, things move about more. I wear a full face mask that consists of a hard plastic shell with a flexible silicone seal. When pressure support (PS) gets over 2 cm of H2O, the mask starts noticeably moving up and down with each breath. Now many people are able to quickly acclimate to the movement but having very low Melanocyte-Stimulating Hormone (MSH) levels, I found the up-and-down movement to be intolerable. (Low MSH means a person has low endorphins so the feel everything more.)
I’ll get into some more details in the next section but when it was all said and done, I found the standard (S) Bi-PAP machine without any adaptive ability, a lower exhalation pressure (EPAP), and lower pressure support (PS) to be quite comfortable – comfortable enough that I could continue with PAP therapy. The three Resmed S9 units mentioned all “fit the bill” because the self-adjust feature in the Auto model can be disabled and the Breaths-per-Minute (BPM) rate on the ST model can be set to zero. In effect, this turns these machines into standard Bi-PAP machines.
Of course, there are other standard Bi-PAP machines but Resmed is a respected name, the machine works with SleepyHead software so I get awesome graphs of my data, and it has nearly all of the functionality of the newer Resmed AirCurve 10 Bi-PAP models – not the Resmed AirSense CPAP and APAP machines. Note: Of course, people with more complex breathing issues will have to use Adaptive Servo Ventilator (ASV) machines and those that suffer from apneas will need a unit that kicks in when breathing stops.
Tweaking PAP Settings
Auto-Adjusting PAP Machines & Ramp
At this point, I’ve made my case for Bi-level PAP therapy for those that are like me and suffer exclusively due to an obstructed airway. I now want to talk about the process I went through in finding pressure settings that worked for me. Along the way, I’ll also explain numerous “comfort settings” that are in addition to core EPAP, PS, and IPAP settings and are intended to make breathing feel more natural.
I started with PAP therapy using the pressure settings from the sleep lab. The expiration pressure (EPAP) was set to vary from 8-12 cm of H2O, and the pressure support (PS) could vary from 4 to 12 cm of H2O. When I was breathing better, the pressure during exhalation was 8 cm of H2O with an inhalation pressure (IPAP) of 12 cm of H2O (8+4=12). If the machine thought I was having an apnea event as I held my breath and rolled over in bed, it would swing into action by keeping the low 8cm of H2O EPAP pressure while increasing the IPAP pressure to a maximum of 20 cm of H2O (8+12=20). On the other hand, if my airway was closing, the machine may elect to increase EPAP while keeping the pressure support at the lower end. It’s all automatic and quite variable.
As I described, having to “tippy-toe” around, being careful to breathe uniformly when awake in bed was a hassle. If I didn’t, the machine stepped into action thinking I was getting into trouble. The problem with this is that the machine doesn’t back down from these higher settings for at least 10 minutes or more. So now I’m lying in bed with the machine trying to jam air into me. Ugh. The initial solution was to reach over and hit the “Ramp” button. However, I sleep lightly so having to reach around in the dark for a button wasn’t going to work long term.
The “Ramp” feature is on all the newer PAP machines. Essentially, it turns down all the EPAP pressures to a low value of your choice and then slowly increases this to normal operating pressures over time. You can set EPAP as low as 4 cm of H2O, and the Ramp time to be as long as 45 minutes.
Worse yet was being woken up out of sleep by the machine as it increased pressures in response to some perceived breathing event. Now I realize that many folks do learn to ignore the higher pressure swings and mask movement they cause, but I’m done with “toughing it out”. I needed a gentler way into PAP therapy.
As such, the first tweak I made was to set the minimum and maximum exhalation pressure (EPAP) settings the same and the minimum and maximum pressure support (PS) settings the same. In affect, I turned off any ability for of my ASV machine to adjust pressures. My machine now acted as a standard Bi-level machine with breath support.
This was a step in the right direction for me. In reflecting on this, I’d always known that ASV machines monitor tidal volume but had mistakenly thought that along with varying the inhalation and exhalation pressures that the machine would also send just the right volume of air making the experience feel natural. I was wrong. It only monitors tidal volume in order to determine to what degree it needs to change IPAP and EPAP pressures. I say this because this is the felt experience. Let me explain.
In terms of how all Bi-level and ASV machines work experientially, there are only two pressures that these machines have to work with. For example, you can sit with your lungs empty and, for as long as you don’t take the even the slightest sip of air, the machine sits waiting – applies a constant low EPAP pressure. However, the moment even the smallest amount of air is inhaled, the machine quickly increases pressure to either the pre-set value in a Bi-level, or to the calculated value that changes on-the-fly in ASV. What this means is that by-and-large, PAP machine pressure changes are “spontaneously triggered” when the person inhales and then stops inhaling.
Breaths Per Minute
As mentioned, some Bi-level models and ASV machines also have a Breaths Per Minute (BPM) setting. This function is needed by people who suffer from apneas – stop breathing. Related to the BPM are settings for the amount of time to be given to inhale a breath (Ti) and the time to be given to exhale a breath (Te) where BPM-Ti= Te. Before being able to actually do some hands-on investigation, I incorrectly thought having BPM and Ti/Te settings would give me more flexibility in adjusting the machine. They don’t.
Breaths Per Minute and Ti/Te settings only come into play if the person stops breathing. When this happens, these setting tell the machine at what rate and for long to vary pressures. In practice, I turned my BPM setting to zero because I don’t suffer from sleep apneas and having the machine kick in when I’m awake and inadvertently hold my breath is bothersome. When you set BPM=0, the Ti/Te settings are disabled too.
When BPM is enabled, it’s fun to hold your breath and watch how these machines quickly start imposing strong pressure swings in an attempt to force air into you. How some folks learn to adapt to these strong pressure changes is beyond me. I got my first exposure to the importance of the BPM setting at the sleep clinic where the BPM rate was set higher than my normal breath rate during the study. The machine relentlessly worked to force me to breath at a faster rate using high pressure swings. Damn, you’d think they could’ve gotten this setting right. Note: I believe you can turn off “spontaneously triggered” IPAP and EPAP pressure changes based upon a persons own breath on some PAP machines. In this case, BPM and Ti/Te would definitely influence the felt experience.
In addition to a BPM setting, ASV and Bi-level Auto machines also look for times when a person starts sipping air. Amazingly, the machines are able to distinguish the difference between light breathing events caused by an obstruction and light breathing simply because the brain isn’t sending out a strong signal. In both cases, these machines sense these events and increase pressures in varying ways depending on the type of event. Note: ASV has the ability to vary EPAP while Bi-level Auto does not.
So it turns out the machines are a lot simpler in their felt experience than I thought. It’s obvious now. Basically, these machines only have two pressures to work with (EPAP and IPAP). Higher IPAP pressure is applied when air is being taken in and otherwise, the lower EPAP pressure is delivered.
I somehow thought the ASV machine could also vary the volume of air it delivers but this is not the case – unless you actually stop breathing and then it forces a volume of air into you. However, as always, it does this by varying the EPAP and IPAP pressures. This makes sense to me that all PAP machines are somewhat limited on the degree that they can vary pressures. After all, it’s a pretty inexpensive looking blower and the hose is 6-feet long. So although machines like Resmed have a PaceWave algorithm that monitors numerous points along each individual breath curve to better determine when a person is getting into trouble, the perceived response is coarser.
As mentioned, Pressure Support (PS) is the difference between the exhalation pressure (EPAP) and the inhalation pressure (IPAP). EPAP + PS = IPAP. On auto-adjusting bi-level and ASV machines, there are settings for EPAP and PS along with a maximum IPAP pressure. They could have just as easily used IPAP and PS, or EPAP and IPAP in their settings but the point is you only need two of the three as the third is derived from the other two.
As discussed, PS has two troubling aspects when it comes to trying to sleep. First, I found that above 2 cm of H2O, the movement induced by the higher inhalation pressure was intolerable. If I was wearing a mask, the mask would move up-and-down with each breath. If I tried a nasal pillow, my nostrils would flare in an out.
Typically, I could fall asleep even with the movement by using a meditative practice. However, I often wake up in the middle of the night. Being somewhat rested, my sleep is much lighter for that point on. I found the constant movement as I tried to fall back asleep to be intolerable.
I tried using various other masks. However, nasal pillows that only send air up through the nose, caused large air bubbles to pop out between my closed lips. I’ve learned that I have a posterior tongue-tie and suspect that this keeps my tongue from making a good seal at the back of my throat. As a result, higher pressure air in my nasal cavity slips into my mouth, skirts along under my lip, and pops out at the front. This is totally annoying and wakes me up from deep sleep.
I also tried a fabric mask that was very flexible and covered both my mouth and bottom of my nose. This eliminated the bubble blowing. However, because the mask didn’t cover the entire nose, the exposed, upper portion of my nose would flare on each in-breath. This effect is counteracted when a full mask is worn as the pressure in the mask is equal to the pressure filling the nose. Again, it was quite annoying. So far, I’ve found the silicone/memory foam seal of the Resmed AirTouch F20 with tightened straps to move the least.
The other issue I had with the auto-adjusting feature was that at times when my breathing became obstructed, the machine would start jacking up the pressures. My ASV machine can not only increase PS but also increase the baseline exhalation pressure (EPAP). I suspect the reason I was being woken up a couple times every night by higher pressures was due to the bigger pressure swings, increased PS. However, the machine does increase the overall EPAP pressure quickly too so it could be that it was just the higher pressures in general.
In either case, I bet you can guess what my next tweak to the settings was. That’s right. Turn down pressure support (PS). At 2 cm of H2O, I find the experience of PS to be very pleasant. It feels like gently being helped to take an in-breath.
Now you may be thinking that I shouldn’t be messing with the PAP settings determined by the sleep clinic. However, for me the options were either no PAP or start tweaking settings. When I was making adjustments, my goal was to make the felt experience pleasant. Later, I would go back and look at the data from the PAP machine along with infrared camcorder, microphone, oximeter, etc. I figured that even if the data didn’t look perfect, that it would be better than nothing. If necessary, I could always work to increase pressures over time.
You know, roughly 50% of folks that try PAP therapy give up. It’s now really obvious why. Those higher pressures are hard to deal with. From what I’ve read, an exhalation pressure of 8 cm of H2O and pressure support PS of 4 cm of H2O is low average. Furthermore, providers don’t tell patients how to get into the “Clinician Menu” so they can change settings. In some ways this makes sense. It’s a liability issue. However, given what I’ve written, it should be clear that with some perseverance, a person can tweak settings and then monitor data to determine the affect.
Lower Inhalation Pressure
If you read Sleep Disorders – Diagnosing & Impact, you know the sleep expert, Dr. Krakow, recommends smoothing out the breath flow rate curve. Pressures are sequentially increased during the sleep study not only to the point where obstructed breathing is cleared but to an often higher pressures that also smooths out the flow rate curve. In my case, it took a baseline EPAP pressure 8 cm of H2O to do this as my normal breath flow rate curves are very choppy.
In terms of the felt experience, higher pressures really aren’t that disruptive. As discussed, a constant pressure if fairly easy to ignore. It’s wide swings between pressure (EPAP) and inhalation pressure (IPAP) called pressure support (PS) that are more problematic. Although, higher overall pressures do tend to cause more mask leaks and I do worry a bit about the fact that brain’s lymphatic system for clearing toxins operates on 7 cm of H2O. Given these considerations, I turned down the exhalation pressure (EPAP) from 8 cm of H2Oto 5 cm of H2O.
In addition to the basic exhalation pressure (EPAP), inhalation pressure (IPAP), and pressure support (PS) settings, the various manufacturers offer additional “Comfort Settings” designed to make the breathing experience more natural.
This setting comes on many Respironic PAP machines with the intention of making breathing more natural. I found it to be just the opposite. Bi-Flex drops the pressure as you near the end of inhalation and during the first portion of exhalation. The felt experience is that of having the machine trying to initiate the exhalation process. Personally, even though it’s natural for the inhalation rate to slow as the lungs fill, I don’t like having the pressure drop out. It feels like the machine is trying to suck air out of me, and it is. I suppose there are medical conditions that would make this setting beneficial but I found it to be anything but natural in feel.
Rise Time is linked to Bi-Flex on Respironics machines along with being a stand alone feature on Resmed units. When Bi-Flex is disabled on my Respironics machine menu, the option to configure Rise Time is made available. Unlike Bi-Flex that starts influencing pressures near the end of inhalation, Rise Time refers to the amount of time it takes for the machine to increase pressure at the end of exhalation. I found this to be a useful setting.
If the inhalation pressure (IPAP) goes up too quickly, it feels like air is being forced into you. If the pressure goes up too slowly, it feels like you can’t pull in the air you need. For myself, I increased this setting to its maximum making the transition from the lower exhalation pressure (EPAP) to the higher inhalation pressure (IPAP) as long as possible.
Found on Resmed machines like the used Resmed S9 VPAP I purchased, I found these two comfort settings to be very helpful. Related to the Trigger setting that affects how quickly the pressure increases at the start of inhalation, if the pressure increases too quickly, it feels like you’re being force fed air. If the pressure comes on too slow, it feels like you’re not able to take in enough air. Similarly, the Cycle setting directed at the transition at the end of an exhalation. If the pressure drops off to quickly, it feels like air is being sucked out of you and that the exhalation is being foreshortened. Being able to tweak the transition both at the start of inhalation and the end of exhalation is very useful.
Feels Good and Works
So you might think that the fact that I disabled the auto-adjusting feature and turned pressures down as much as 50% that my sleep data would look bad. It doesn’t. I was really surprised by this. In fact, I tried even lower EPAP pressures but below 5 cm of H2O and the data showed serious issues. The flow rate got really truncated, I was snoring loudly and being awoken, and felt miserable the next morning.
In terms of the actual data graphs for the Dreamstation BiPAP AutoSV, the Encore Pro 2 software showed numerous events with an average AHI score of 0.8. This is considered a pretty good score in the CPAP world. However, when I cross referenced each of the supposed breathing events in the video, each and every time, I was awake. In other words, nearly 100% of the events were false-positives so the actual score was even better.
With the same settings on the Resmed S9 VPAP machine, I slept just as well. In fact, I’d say that it felt even more natural on this used machine than my expensive Dreamstation. The difference being the tigger/cycle setting on the Resmed. In terms of data, there wasn’t even one event recorded on my 4-hour trial, AHI=0.
So I’m feeling pretty good with the tweaking that I’ve done. It’s made it possible for me to actually use PAP therapy. In addition, the data shows that although the breath rate curves are a bit choppy, I’m no longer “sucking air through a straw” for much of the night. Upon waking, I feel a bit more revitalized. My night sweats are nearly gone. I’m not as sleepy during the day. I actually enjoy the felt experience of having my breath gently supported and especially like knowing that it is addressing the bulk of my sleep disordered breathing. With PAP in place, I can now look at other treatments that will hopefully address the underlying cause making PAP a helpful albeit temporary fix.
Purchasing & Cleaning a Used PAP Machine
I really like my used Resmed S9 VPAP machine. VPAP stands for a bi-level machine. It comes in varies models. There is the Standard (S) model, the (ST) model for those that suffer from apneas, along with the (Auto) model for when you’re looking for a machine that can automatically increase inhalation IPAP. Any one of these machines would have worked as I only needed the (S) model features. The additional functionality of the other two can be disabled essentially making them into (S) models.
I bought my machine through Craigslist from a guy out of state. I was a little leery of doing this but I used PayPal and apparently this offers some protection against fraud. From my experience, I would recommend asking these four questions before committing to buy.
- What does it say next to the on/off button – VPAP ??? (when seller doesn’t list the model)
- Has the machine been cleaned with bleach or a “perfumed” cleaner?
- Are there any error messages when you plug it in?
- When you press the “I” button and then turn the dial to “Service”, how many “Run Hours” are on the machine.(Under 5,000 hours is rare; mine had 7,000.)
When the machine arrived it smelled like bleach and fabric softener. The guy stated that the machine had been “sanitized” so I’m guessing it was cleaned with bleach. Bleach can actually permeate plastic and off-gas for a very long time. The best way to neutralize it is with hydrogen peroxide (H2O2). I had a quart of concentrated 35% H2O2 that I diluted down to 10% with distilled water. Although, regular 3% H2O2 would have been fine.
Update December 27, 2017
I purchased a second, used Resmed VPAP for my Mom with 19,000 hours. This machine was much dirtier. Everything cleaned up fine with no odors except for the silicone blower mount and seal. This rubber gets exposed to airflow and smelled like fabric softener. Yuk.
Hydrogen peroxide and rubbing alcohol wasn’t enough. Apparently, ammonia neutralizes fabric softener smell so I tried using it without diluting. After rinsing in water and soaking a few minutes first in vinegar and then baking soda, to remove the ammonia, it was a lot better but not perfect. I then used straight bleach followed by rinsing in water and then neutralizing with hydrogen peroxide. That seems to have worked. My advice would be to get a machine with fewer hours as they clean up much easier in terms of odors. Note: Wear a carbon mask, gloves, and goggles. Also, ammonia can degrade silicone over time so limit the contact time.
In terms of taking the unit apart, I found a few very helpful teardown directions and went on to make a video showing assembly. The two minor issues I had in disassembling the unit were that I couldn’t find my long torque-bits, you need a long T10 to reach some screws, and you have to be careful prying off the covers. I used a ground down nail for a torque bit and my old putty knife with rounded corners to pry off the housing. That way if I slipped, I wouldn’t gouge the plastic. Other than that and the machine came right apart.
Inside, everything can be thoroughly cleaned except for the sealed motor and circuit board. I took all the other parts and soaked them in a bucket of H2O2 for an hour to neutralize the bleach. I then dried the parts followed by dipping them in rubbing alcohol and wiping them down. It was easy to remove any trace of odor from the plastic and silicone parts.
In the base of the unit are two foam pieces that I’m assuming are for sound damping. Initially, I just used soap and water. It wasn’t enough. I then soaked them in H2O2. It still was not enough. When I went on to use rubbing alcohol, the pieces expanded about 25% but shrunk back down to normal when I rinsed them out. Eventually I got all traces of odor out.
Cleaning the blower motor was tedious. There are fan vanes on the bottom that can be accessed through the intake hole on the bottom of the blower. My wife showed me how to twist the end of a toothpick in a cotton ball to make a miniature Q-tip. I’d roll as much cotton on the end of a toothpick while still being able to get it in-between the small vanes. Before using, I dunked the cotton tip in some rubbing alcohol. The vanes were black; it took about an hour to clean them.
Unfortunately, I could not get to the small set of fins on the other end of the motor or the laminated body of the motor inside the clear plastic housing. After several different cleaning attempts, I actually took the motor and submerged it in rubbing alcohol with a electric stirrer hooked to one end. Using the stirrer, I spun the motor for a couple of minutes in the rubbing alcohol. I then dried it off with a towel and hair dryer – no water.
The motor is working fine to date. Unfortunately, the alcohol didn’t get any more dirt off. We’ll see if this shortens the life of the motor. I don’t recommend doing this.
I finished by using ozone. I have an inexpensive Enaly ozonator for fruits and vegetables. After the alcohol bath, I used “painters tape” to connect the ozone line to the open hole on one end of the motor. I ran high concentration ozone through the motor for two hours. I didn’t notice any smell after that but my wife detected a faint “burnt” smell. Hmm, maybe I gave it a bit too much ozone. It’s a faint enough smell that isn’t noticeable when the blower is running with lots of fresh air flushing through.
I blew off the circuit board and and replaced the CR2032 watch battery. That’s all. It didn’t smell and this isn’t surprising as it’s not exposed to the moving air and is protected by the housing. Of course, I was careful to thoroughly dry all the parts and blow out the screw holes before reassembly. You don’t want to drive a screw into a hole filled with liquid as it will crack the plastic.
I had to ozonate the carrying bag for three hours so it doesn’t smell like fabric softener. Out in the garage, I put the bag in a large tupperware and ran the line of my Enaly ozonator under the lid. I turned up the ozone to maximum and let it run.
The only part I had difficulty getting the chemical smell out of is the black rubber seal on the humidifier section. It’s not silicone like the other gaskets. Eventually, I used ammonia followed by vinegar and baking soda solution to neutralize the ammonia. My solution was to cut a strip of aluminum tape used for duct sealing and cover all but the sealing portion of the rubber where it contacts the plastic pipe of the blower unit.
With a little care and patience, it’s possible to thoroughly clean a used PAP machine. The machine I got really reeked. Now, it’s completely fine.
PAP Accessories & Tidbits
- I haven’t found humidification, or heating of the tubing that runs from the machine to the mask, to be necessary. Perhaps it’s because I’m using fairly low pressures. A reader, Nancy H, has commented that not using a humidifier can lead to dry eyes and sinuses. For now, my mask isn’t leaking and blowing air at my eyes and I don’t lie in a way on my pillow such that the exhaust air from the mask is directed at my face. I also like to wear a sleeping mask so this does offer some protection against blowing air. Nevertheless, it’s good to be aware of this issue.
- Although both machines are quiet, it does sound a bit like “Dark Vader” with my mask on. This is way worse when I take off the humidifier section on the Dreamstation BiPAP AutoSV versus the Resmed S9 VPAP. I could probably get used to the sound on the Resmed (not the Dreamstation) but instead, I currently keep the humidifier section attached albiet with an empty water tank and humidification turned off – so it doesn’t heat up the empty plastic tank and release even more phytoestrogens. In addition, I run a white noise machine at night.
- Even though I don’t put any water in the humidifier tank, I clean it along with the hose and mask daily. The hose and tank are cleaned in water with a bit of mild dish soap. I run a stiff brush down the hose each time – the more flexible hoses are a pain. Everything except for the mask goes into a Hurricane CPAP Dryer for at least an hour.
- Once a month, I run ozone through my PAP machine and hose. Rather than buying a SoClean, I use the same inexpensive Enaly ozonator that I used to de-scent the blower unit by connecting the ozonator to a $7 SoClean Adapter that fits between the PAP machine and the hose. As such, the ozone has a chance to waft through both the hose and PAP machine. Note, to make sure ozone travels through both the hose and machine, it’s probably best to close off the end of the hose for a time followed by closing off the intake under the air filter on the PAP machine for some time.
- I clean my Resmed AirTouch F20 mask with the tip of a clean cloth soaked in rubbing alcohol daily. I’ve found that you have to be quite gentle with the memory foam or it will begin to shred a bit at the inner edges. I’ve been using mine for over a mouth and it looks almost new and works fine.
- I replace the air intake filter(s) monthly with better quality after-market filters. My new Respironics has an optional “ultra fine filter” that I use along with the standard course “pollen filter”.
- My mouth tends to open at night. This isn’t good. I could mouth tape but I like wearing a Respironics Chin Strap instead. I like the chin strap for two reasons. First, it keeps my lips sealed. Second, it helps hold my lower jaw mostly closed thereby reducing the amount my lower jaw can drop back into my airway. Most chin straps pull the jaw back and this isn’t good. I’ve found that I can position this strap forward on my head so it comes close to pulling straight up on my lower jaw.
- Before starting PAP therapy, and in an attempt to keep my lower jaw from sliding back and closing my airway, I tried wearing the Respironics Chin Strap along with using a Moldable Double Mouthguard. The mouth guard has a hole in the front so you can breathe through it if necessary. I’m guessing this may work wonders for some as the two basically function as a Mandibular Advancement Device.
- Both the Respironics and Resmed machines have bright blue lights on them. Although you can turn down the intensity and they turn off automatically, blue light tends to wake a person up. Another design nuisance are the convoluted humidifier tanks. You’d think they’d make the tanks with big round corners so they’re easier to clean.
- I was experiencing mild stomach pain from Aerophagia (air in the stomach) that went away with the lower pressures.
Wow! You’ve answered all my questions on CPAP, BPAP, etc., and much more! I’ve shared your article with my partner, who has apnea. Thank you for delving into this. It’s so helpful and insiteful.
Thanks for your kind words and taking the time to let me know the article was helpful.