BILEVEL PAP Therapy Pearls: Clearing the First Hurdle

Bilevel Pearls #1

To start a Bilevel discussion, we must begin with a basic point about what we call the “Control of Breathing” paradigm, which may not be relevant to many experienced CPAP users. However, because this issue is the very first tangible barrier to success for potentially any first-time user of bilevel, it’s always worth addressing up front. In fact, in our sleep lab, we train the sleep techs to broach this topic very early in any PAP therapy desensitization.

Patient Perceptions of Breathing

“Control of Breathing” is all about helping patients clarify how they perceive their own breathing, because it turns out that many SDB patients, particularly those with overt anxiety (and even some with what can be called covert anxiety) do not fully appreciate the lack of control they actually possess over breathing.

Take a few breaths. Watch and listen to yourself breathe. No doubt, you can do things to influence your breathing, make it faster, slower, deeper, lighter…even stop it for awhile, but you do NOT control your breathing.

Self-Awareness of Breathing Changes

You just breathe most of the time without any awareness of it….except of course when things change. You notice your breathing when you:

· Run
· Laugh
· Cry
· Drink
· Eat
· Talk
· Make love
· Deliver babies
· Snorkel
· And when you first put a strange-looking mask on your face connected to a tube and device that pumps air into your nose or mouth to supposedly make you sleep better!!

In all these situations, you notice your breathing more because you may have to adjust something to make sure the airway is protected (swallow food correctly, then breathe) or working in an optimal way (thrusting your chest forward to breathe deeper).

Perception of Breathing with Bilevel

But, with PAP therapy, the process is unique. You are being asked to receive “extra” air, because your “breathing tube” won’t stay open. Now, this process doesn’t feel so weird on inspiration, because when you breathe in, a little extra air (pressurized airflow) can initially feel comforting, akin to the physical and psychological pleasure you feel in your chest wall when you take a deep breathe.

Expiration though is a breath of a different color. No matter what you may think about pressurized air rationally, the very thought of it coming in while you are trying to breathe out will trigger a variety of sensations that do not feel pleasurable.

Key Point of PAP Discomfort

And this is the key point: as soon as you feel the unpleasantness of pressurized airflow, particularly during the expiratory phase of respiration, then if you also labor under the myth that you are in control of your breathing, your central nervous system is going to sound “Battle Stations!!!!” as fast as it possibly can.

What we’ve learned in the past year in particular is that this response is clearly psychosomatic in probably 99% of patients. That is, it is the person’s reaction to pressurized airflow that clearly worsens the unpleasantness associated with the process. It may start out as feeling uncomfortable, but then this feeling makes the person more aware of the experience, which then amplifies the experience, triggering more anxiety, and so on, until the some patients develop outright claustrophobia or panic.

Self-Guided Imagery to the Rescue

We learned that most patients with this adverse response can distract themselves with self-guided imagery, and in a few minutes they will notice that the unpleasant sensation fades. Ideally, once it fades, you would like to ask the patient to turn their attention back on the awkwardness of breathing out against air coming in. The unpleasantness should return, at which point, we ask the patient to initiate imagery again, and soon the unpleasant feeling goes away again. This alternating process is extremely instructive in persuading the patient that it is his or her reaction that is actually magnifying the problem. It also gives the person great confidence in realizing he or she can make the uncomfortable feeling decrease or go away completely.

Initial Negative Response to Bilevel

The overwhelming majority of patients who use bilevel for the first time and don’t like it or don’t feel like it was more comfortable than CPAP are “fighting” with the machine in the context of the discussion above. They are imagining that bilevel, by switching during inspiration and expiration, feels like it is trying to control their breathing; therefore, they perceive they must do something to get in synch with this machine. But, it’s almost impossible to do so and actually fall asleep.

Just as we tell all insomniacs, “you don’t control sleep, you just let it happen,” the same is true for breathing. You don’t need to control the bilevel machine, and it’s not trying to control your breathing. If you just breathe your normal way, sooner or later, you won’t notice that bilevel is doing its thing.

Summing Up

Again, experienced PAP users may find the material above old news, but I wanted to make sure that first time users understood that there is a “first-time adverse effect” potential for bilevel among users who do not understand the “Control of Breathing” paradigm. Undoubtedly, this problem arises in first time CPAP users as well, but we have found that the problem can be especially acute and severe in bilevel users, because the alternating pressure changes that occur on I to E or E to I are unique and foreign and potentially a stop-you-in-your-tracks barrier.

Critical issue and I'm amazed to see a physician who can say imagery in the context of a medical topic. As patients or physicians, once there is a medical diagnosis there is a tendency to "medicalize" responses to the diagnosis and the treatment. Ironic that non-pharmacological interventions often get little attention until a patient gets a psych related label or start to be seen as drug seeking. Sorting out the mind connections at the beginning can go a long way. So many people still interpret the mind-body connection as being told something is "all in the head"; or shrug off the intervention as trivial.

If I understand this correctly, the feeling that I get that my BiPAP is rushing my breathing is all in my imagination. Is that right? It often feels like the change from inhale to exhale and exhale to inhale is too fast and the machine wants me to increase the speed and frequency of my breathing. (Currently BiFlex is set at 2)

I like the thought of guided imagery to overcome this sensation. I hadn't thought of using it for that purpose before.

Thanks for the "pearl."

Susan

This is great! I have a relative who I think will be getting a bipap. I think he also has some of these issues. I'm going to print it out for him and anyone else who has these problems. Thanks for the well organized summary that's easy to understand. When I first started cpap, I used guided imagery to help myself get to sleep. I still use it if I have problems sleeping in general. It works like a charm.

Bilevel Settings

Bilevel settings can trigger too rapid of a transition from I to E or E to I, so if a machine feels like it is cutting off inspiration by switching to expiratory pressure before you finish inhaling or if it feels like it is cutting off expiration by switching to inspiratory pressure before you finish exhaling, then it is unlikely that your imagination is the cause.

The settings on different bilevel machines vary with respect to how to trigger the change from I to E or E to I. If these settings do not seem like they are set right for you, then they probably are not, and no amount of self-guided imagery is likely to resolve the problem.

However, having said that, if you are anxious about the bilevel transition, then it is conceivable that your reaction is over-responding in some way that sets you up for a "cut-off" feeling. Still, in all the cases I've seen of bilevel in the last 3 years, the experiences of inappropriate "cut-off" are almost always having to do with the way the machine is set.

In a subsequent post, I'll be describing more specifics about my use of the PB 425, which has these really cool sensitivty settings for inspiration and expiration that I not only use personally, but we have also installed these machines in the lab to fine tune the patient's bilevel "cut-offs" to properly synch with the patient.

Quick Heads-Up on Personal Messages

I do not object to receiving Personal Messages, but I must explain why I cannot respond to them.

As a physician, medical ethics require that I have a doctor-patient relationship with an individual to respond to a question that might alter their current treatment. So, for example, a couple people have used the PM function to send me questions about settings on machines, etc. For what I believe are obvious reasons, if I were to respond, they could choose to alter their settings based on my comments, and that would be a clear violation of the standards of medical ethics on my part.

Recently, someone wrote about a question regarding auto-bilevel, and in a subsequent post I will be able to make comments that will most likely answer part or all of the questions raised, but by doing so generally, this person will likely get some useful information as opposed to any sort of direct communication.

However, even in this case, I must spell out that I am always offering my opinions based on the belief that people make changes to their devices based on their discussions with their sleep docs or through arrangements with their sleep docs who have authorized them to learn how to change settings on their machines for fine tuning adjustments.

It is obvious from the advanced level of communication on this forum that many individuals are "taking matters into their own hands" with respect to the fine tuning of their machines, etc. I simply have to state that my information represents general knowledge, including specific tips on how I might have managed such and such a case.

I offer this information in good will and with the expectation that no one is operating under any other assumption that would lead them to believe that we have developed a doctor-patient relationship and all that that entails.

If someone needed to develop such a relationship with our sleep center, they can visit our website for more details.

I look forward to making further posts on this very intellectually stimulating site.

Thanks your consideration of the points above.

Although I am not currently on a bilevel machine, I found the post to be very informative. I also understand the need for the post "A Quick Heads- Up on Personal Messages." Thank you for taking an active part in the forum. You provide a great deal of useful information that can help many to be successful in their treatment.

I am a Nurse Practitioner with no experience in sleep disorders-one thing I do know is that it is important to give a "good" history. Yes the care provider has to ask the right questions-and it can be difficult when a patient says yes to every symptom on the list. The general information gained through this forum & Dr Krakow's posts recently enabled me to zero in on pertinent symptoms/complaints I had and convey them clearly to my sleep physician.
Living in rural area it is a long way to doctors. I ask for parameters/a range within which to adjust my treatment. If my problems are not controlled within that range; it is time for a followup appointment. My policy is not to see someone I don't trust and who does not trust me. That does at times leave one with few choices in this neck of the woods.

Dr Krakow, from what I read at your website; a person who cannot find a physician they trust and who wishes to have you consult regarding their care can have their sleep/medical records sent to you and you will provide telephone consultations if you feel you can provide appropriate advice. For example you might decline to consult if the medical records are incomplete. Assuming you must also feel some mutual trust with those you consult with. Your website clearly outlines a fee structure for this consulting and clearly states insurance does not pay for the consulting.

Thanks again for all the collective knowledge and experience represented on this forum.

Thanks for clarifying that Dr. Krakow.

I think I'll do some more fiddling with the Biflex settings since that sensation is disconcerting at best and annoying at worse. I don't really like to think about my breathing, and the machine's pace has forced me to do that.

Susan

BarryKrakowMD wrote:Bilevel Settings

In a subsequent post, I'll be describing more specifics about my use of the PB 425, which has these really cool sensitivty settings for inspiration and expiration that I not only use personally, but we have also installed these machines in the lab to fine tune the patient's bilevel "cut-offs" to properly synch with the patient.

Did you try other Bipaps first? Is this machine unique in some way compared to Respironics machines?

Hi All,

I believe all the machines are build to the specific manufacturers design intensions....the question is what are the advantages and disadvantages and outstanding features/functions/upgradable etc.

Mckooi

Dr. Krakow, I've not used the PB bilevel, but have used several bilevels by Respironics and resmed. I should hasten to say that I don't really need bilevel therapy...straight cpap at 10 would treat me fine and I can exhale easily against that. I've used several models of bilevels just for "the fun of it", to see what they were like. I do like bilevel pressure relief for exhaling. Very comfortable. Feels like natural breathing.

I noticed in both the Respironics and resmed bilevels, 4 seconds (as best I can remember - I may be mistaken about the exact amount of time) was the longest amount of time those bilevels could be set to deliver IPAP. Of course, if a person stops inhaling, or starts to exhale before that time is up, the machine switches to the lower EPAP pressure, regardless of how long the IPAP is set for.

Does the PB425 allow a longer time to be set for duration of IPAP?

I realize that most people would not usually inhale for 4 seconds, or even close to that. About the only way to have a steady inhalation feel cut off with machines set for that length IPAP, is if the person took an occasional really long, slow breath. So, I understand that allowing as much as 4 seconds for inhaling is considerably more than enough...for most people, most of the time.

My question: I wonder why 4 seconds for maximum length of time to allow for IPAP was chosen by the manufacturers? Why 4 seconds rather than, say 5 seconds or 6 seconds, which would more easily outlast an occasional slowwwwww, long inhalation?

I just wondered if 4 seconds was a somewhat arbitratry number pulled out of the hat by the mfgrs, or is there a particular reason why 4 seconds is the longest they chose to let IPAP last should a person inhale occasionally for that long.

I'm talking about the "regular" bilevels using just spontaneous mode. Not a spontaneous/timed model. Although...hmmm...now that I write that, perhaps the earliest bilevels were all S/T machines and were expected to be used with a timed backup rate set? I can imagine that if the first ones were all capable of having a timed breath rate set, perhaps it really was necessary to cap the IPAP time for a duration of 4 seconds? I'm terrible at math, so maybe there was an obvious mathematical reason for that.

I suppose that in the beginning, bilevels were developed to address some specific treatment issues rather than for just more comfortable exhaling. Perhaps there were physical conditions associated with certain diseases, in which IPAP pressure being delivered for longer than 4 seconds would not be a good thing, even if the person really did normally inhale that long?

Internet Access is a bit spotty in the Atlantic time zone, so posts may have to be shorter, certainly a good antidote to my long-windedness.

Consultations

Yes, we make all sorts of consultations. The ideal, regarding what is know as telemedicine laws, would involve the patient's primary physician or sleep physician contact me for support/advice on treatment issues. However, I have also had patients conact me directly, and we make it clear that we are establishing a doctor-patient relationship, based in NM with the assumption that the patient might seek care at our center some time in the future. In these instances, we like receiving medical records of previous sleep tests, and we also have the patient fill in our lengthy online intake forms at the center's website. Last, rarely a patient just asks to call and chat with several questions to discuss. In this type of encounter, where there is less formality, it's important that I discuss things in more general terms such as, "When I have seen patients in the past with some of the concerns you have, we have managed them in the following ways."

If these points seem overly precise, keep in mind that some state board's of medical practice in the USA are very determined to hold back telemedicine and may have an interest in targeting physician's who try to "practice" medicine in their state without a license. Thus, those who conduct activities like what I've described above must be cautious to maintain certain standards to demonstrate that I am not practicing anywhere but in New Mexico.

General Bilevel

I'm not aware of any bilevel machine setting a breathing duration by number of seconds, but I don't know all the details about all the machines.

All of the machines as far as I know have a rise time setting that indicates how long it takes for pressure to rise from EPAP to IPAP once the person starts inhaling. The settings on rise times are usally in a range of 1 to 5 or 6 with the higher number usually indicating an allowance for a longer period of time to increase to the highest (IPAP) pressure as a means of more comfortably transitioning during the bilevel E to I switch. But, this transition phase is marked in milliseconds as I understand it.

PB 425 Bilevel

The PB 425 has a most unique setting called "sensitivities" for both inspiration and expiration, that is, two distinct settings. These sensitivities determine how easily or how hard you want to make it to trigger the change from I to E or from E to I. The scale is 1 to 10, with lower numbers reflecting greater sensitivity, that is, faster triggering of a switch, whereas higher numbers reflect less sensitivity, so the machine needs more input from the patient's natural breathing to make the switch.

As an example, we note that insomnia patients with SDB and anxiety have some trouble with being able to "finish inspiration" before being cut off by a drop off in pressure to expiration. So, we set the I sensitivity very low to easily trigger IPAP, but we set the E sensitivity very high so that EPAP is much harder to trigger, thus giving the patient more time to finish inhaling.

We like the PB 425 because we can adjust the 2 sensitivity settings in the sleep lab and actually monitor this process while the patient is asleep.

Sleep vs Wake Sensitivities

We think we're learning something very intriguing about this system, because it seems to produce very different results depending upon a sleeping or a waking state. In other words, if you try to set someone's sensitivities while they are awake, the patient will always select something that feels most comfortable. But, if you then test the patient in the sleep lab, the sleep tech will usually discover that the sleeping patient breathes more comfortably with a different set of sensitivities.

I believe this finding is in harmony with the fact that we really do breathe differently under sleeping conditions. And, I think it's yet another reason why we so strongly emphasize retitration studies in the sleep lab for PAP therapy users.

I have a quick question concerning BiPAP.

My respiration before sleep and asleep are completely different from what I've seen on my titration. I have prolonged breathing while I'm about to sleep but it comes back to a normal breathing when I'm sleeping. My question is, does the machine take this into consideration or just go from say 7-17 without really knowing when I inhale-exhale?

Thanks for your answer.