Our model of practice only considers a fixed CPAP device for classic sleep apnea patients, meaning those with classic breathing symptoms, daytime sleepiness, and few if any co-morbidities. That said, we honestly have not prescribed a fixed CPAP device since 2005. All told, among the thousands of patients we’ve seen, maybe a dozen or two are using an auto-CPAP device (APAP) and almost always with expiratory pressure relief. In more than half these limited number of cases, the individuals presented on the APAP device while seeking 2nd opinions from our center and made clear from the outset they had no interest in or means of switching to a different device. As described from the last post, you will not be surprised to know we still found signs of EPI on some of these patients, yet they were not motivated to switch to a dual pressure system. On rare occasions, some patients visited us again, say 5 years later, and then asked about obtaining a new machine. Even so, when switched to a dual pressure apparatus, these patients usually say, “yes, it’s more comfortable, but I don’t notice any difference in my sleep or other symptoms.” To them, all PAP therapy is equal in the strictest sense, and in my opinion, their observations appear unique to classic OSA cases.
With CPAP devices, then, the only trick a person must apply, if in fact they use CPAP and suffer subjective EPI, is an imagery distraction technique to see what transpires. Unquestionably, many patients use fixed CPAP devices with great success, and we would wager the largest proportion of these cases are the classic sleep apnea cases as opposed to what should probably be termed “common sleep apnea” cases, because in truth, when the physician takes a thorough history on any OSA/UARS patient, chances are extraordinarily high several comorbidities will be identified, many of which disrupt sleep or directly interfere with the capacity to use PAP. If you are not quite clear on this point, consider the sensitivity or brittle nature of a diabetic’s skin turgor and resiliency, and then picture what it is like for such a patient to constantly deal with mask fitting issues to prevent even the slightest amount of skin abrasions or worse. Or, consider a patient with dysthymia or depression and how easily he or she falls through the cracks due to persistent non-engagement, no matter how much education or coaching they received.
Most people who come to sleep centers for help with sleep breathing complaints do not, I repeat, do not just have sleep apnea. Probably 50% of OSA/UARS cases suffer clinically meaningful insomnia. Another smaller but sizeable proportion of patients suffer from leg jerks. In older populations, many conditions frequently co-occur such as cardiac diseases, strokes, menopausal symptoms, gastrointestinal complaints, pulmonary conditions…and truly the list is never ending! These are the typical cases at most sleep centers, and they require a great deal more attention than a classic sleep apnea patient.
To simplify, think of the common sleep apnea patient as someone who is suffering from so many other health conditions, they must inescapably feel more on edge, vulnerable and anxious about dealing with yet another disease or disorder. This anxiety state then bleeds into their experience, and finally, in turn literally surfaces as they attempt use of PAP. Speculatively, anxiety may emerge during the sleep period if the patient experiences PAP as a threat. The end result is to fight with the pressurized airflow, which again speculatively could equate to the findings of subjective EPI while awake and objective EPI while asleep. Therefore, we are not surprised these patients do not fare well with CPAP therapy, which brings us then to our new discussion of how to assist patients trying out dual pressure systems or a dual pressure system with a built-in auto-adjusting algorithm.
A fixed BPAP device provides a great deal of expiratory relief for many patients, but it also may (and not infrequently) provoke an instantaneous patient response to “take back” control of one’s breathing. If bilevel feels like a threat by seeming to take control of breathing, we presume the “take back” response arises automatically, because so many people report the problem when first exposed to bilevel. Yet, perspective is key here. If you had been struggling with CPAP to the point of noticeable anxiety about the discomfort from breathing out against pressurized air, then unquestionably bilevel could feel like a veritable breath of fresh air while exhaling. On the other hand, if your discomfort with CPAP were vague, uncomfortable or otherwise difficult to apprehend, then your entire focus might be centered on the noxious bileve-induced feeling summarized as follows: “Hey, I haven’t finished breathing and now it’s making me breathe out, but I still want to finish breathing in so I can catch my breath.”
Thus, a bilevel device could trigger either immediate relief or immediate discomfort. The person who rapidly appreciates relief usually perceives the “change in direction” in airflow as a minor annoyance or no bother at all. Whereas, for the person who is most bothered by the change in direction, it will prove critical to teach him or her how to pay attention to bilevel’s expiratory relief with hope of diminishing their sensitivity to the change in direction. Clearly, the greatest barriers occur in the person who feels no expiratory relief and amplifies the sensations of the machine’s change in airflow direction.
If you have never tried a fixed bilevel device, it is well worth doing so, because as you pay close attention to the change from inhalation to exhalation and back to inhalation, you will feel how much energy you must expend trying to time the sequence just right. Even then, it may feel all right or reasonably comfortable, but the mindset would soon develop you must maintain a constant vigilance over your own breathing cycles and that of the machine to match them as closely as possible. This strategy will almost always wear out even the most dedicated patient, so much so they might declare the work of synchronizing to the bilevel delivery triggers feelings of less sleepiness and more alertness. In sum, the bilevel patient on first exposure might develop insomnia.
Similar to what is described above for CPAP or even APAP, the imagery distraction will also work well with BPAP. However, it may prove more difficult if the change of direction feeling provokes so much discomfort that the titration must begin with fixed CPAP, after which bilevel is instituted once sleep emerges. Nonetheless, with imagery distraction not only can EPI be resolved while awake but amplification of the change in direction sensation will also subside if the patient achieves a moderate or greater level of distraction. Although we like imagery distraction best, because imagery and related dreamlets are very much a part of the falling asleep process, we appreciate some individuals will do better with another type of distraction such as music, white noise, or even games like a crossword or sudoku puzzle while sitting up in bed prior to sleep. The latter approach of course is the most interesting technique, because it allows patients an easier opportunity to experience the relaxing pleasure of the puzzle and then suddenly realize the whole “change in direction” sensation is subsiding when they are still awake. For your most sophisticated patients, they may greatly appreciate the subtleties of distraction followed by too much attention to breathing followed by renewed distraction, so that in short order they develop a tremendous sense of control over the process.
There are two more devices to consider, ABPAP and ASV. They have similarities so we’ll take them together at first, and then comment on unique qualities. Due to the auto-adjusting features in the algorithm of each device, these systems create another type of confusion in the mind of vulnerable patients, because through attention amplification they will notice subtle changes in pressurized air levels. Even though these devices are designed to produce a more natural or physiological delivery of air, some patients might immediately feel like the machine is trying to control their breathing. As always, start with any of the distraction techniques described above, depending upon whether the patient is starting with the device in the lab or at home. We favor the imagery distraction for anybody, anywhere because it is self-empowering, but we recognize some will need external cues such as music or white noise machines or puzzles.
One of the most problematic features on either of these devices is its response to leak. Many devices are designed to detect leak and amount of leak and then alter the volume or pressure levels delivered. Sounds like good thing, right? Yet, it is not unusual for patients to report a “blow-out” effect wherein they feel sudden and overwhelming bursts of pressurized air. In these instances, we think of this problem as “nuisance leak” (actually, any leak the patient consciously experiences that thwarts PAP use can be deemed “nuisance leak”) and presume it is intolerable for anyone using the device. Therefore, it is critical to solve the leak issue as soon as feasible, but if the leak issue cannot be resolved right away, then sharply lowering the pressure settings will perforce lower the degree of nuisance leak and possibly diminish the blow-out effect as well.
With ABPAP devices, there may be a small to large number of bells and whistles that come standard with the devices, and most or all these adjustable elements may enhance patient comfort. As we titrate all our ABPAP (and ASV) patients in the lab and manually override them to improve the comfort and efficacy of the device, it is very useful to tinker with minor adjustments on the devices to enhance the naturalness of breathing. Nearly all patients for whom we have titrated ABPAP report greater comfort subjectively and demonstrate greater consistency objectively in the sleep lab by tweaking the devices. We have had the most experience with the RESMED ABPAP device, but we assume other devices have some similar adjustment capabilities.
For ASV, the patient must contend with the special feature of the backup system, which if you are experienced enough to remember the old bilevel ST devices, then you know that such systems were in use as recently as 5 years ago and were fraught with “control of breathing” issues for nearly every patient. ASV’s backup rate system seems much different (again we have the most experience with the RESMED device) in that it is delivering a volume of air that often mirrors 90% of the alleged normal volume of air detected for the individual patient. Thus, even though there is a set delivery rate for this volume of air, e.g. 16 breaths per minute as the backup rate, the sensation does not feel forced or regulated in any way. Indeed, I’ve been using ASV or ASVAuto for several years now, and there are many times where the volume so matches my apparent “normal” volume that it is difficult to detect the actual pressurized air. Instead, I feel as if I am breathing without attachment to a device. Throughout the night, auto-adjustments occur on the 90% algorithm, but when manually tweaking these settings in the sleep lab, it is our perception that we are increasing that percentage somewhat.
With ASV, blow-out remains a problems, but it may not necessarily be related to leak. When we first used the ASV devices, we learned many patients had considerable difficulty in the first few minutes. The only theory we developed to understand this problem was that if patients were already anxious about the process, then it was quite likely they were engaging in erratic breathing patterns and perhaps the machine was responding erratically to large swings in the air volume generated by the patient. We developed a counter-intuitive strategy for these ASV patients in which they were instructed to “control” their breathing when first turning on the device. The recommendation was to first breath just a little bit slower and shallower at onset, so the machine would not overreact. We never conducted research on this approach, but it’s now standard in our practice, because so many patients who applied the strategy reported immediate benefits and no further instances of blow-out. When an insomnia patient awakens at night with the same side-effect, we recommend they start again with this “control” technique. Obviously, this instruction should only be needed to guide the patient for a few minutes, otherwise it would lead to the initial problem of “over-controlling” we have been discussing. Since ASV seems to be associated with even faster sleep onset than any other devices we have used previously, we think the initial instruction to control breathing with slower and shallower breaths has worked well with this remarkable technology.
Summing up, for general discomfort from pressurized air and the specific problem of managing expiratory pressure intolerance, it is crucial to guide patients in the appropriate distraction techniques that often dissolve the attention amplification process and lead to more rapid adaptation. When EPI does not respond to such techniques or otherwise worsens, switching the patient to ABPAP or ASV, as appropriate, often leads to a decidedly better response. However, again general discomfort and even mild or residual EPI might need to be addressed, and the patient can still benefit by learning to avoid paying attention to their breathing while awake. For objective EPI that lingers with ABPAP, it usually means the patient is only going to adapt well to PAP therapy with an ASV device, regardless of whether or not they suffer from complex sleep apnea. For objective EPI that lingers on an ASV device, there may be no specific treatment save time and an extended period of artificially lowered pressures, which provides the patient a chance to reduce their anxiety or related emotional tension, after which pressures may be gradually increased without provoking subjective or objective EPI.