What is CPAP Failure?

In previous blog posts, I have talked extensively about how a patient may not respond well to a basic CPAP device and therefore might want to consider a more advanced device such as APAP, BPAP, ABPAP or ASV. I want to drill down on this topic to specifically highlight the technicalities involved in determining whether or not someone has failed CPAP. It may surprise you to know there is no formally accepted definition of this concept, which means the interpretation of CPAP failure can range far and wide and have considerable impact on your capacity to move forward with a newer or more advanced PAP technology.

In the most obvious scenario, a person uses the CPAP device for several weeks or months, meets the compliance standards of the insurer’s coverage policy (e.g. uses 4 to 5 nights per week and averages more than 20 hours per week), yet reports no improvement in symptoms, most notably the complaint of daytime sleepiness persists. At some sleep centers that do not routinely measure outcomes (e.g. sleepiness, insomnia, nocturia, mood, or cognition), this patient might be assessed as “compliant” and therefore no further evaluation or changes are needed. This point may surprise you as well, but lamentably, there are many sleep centers that make the assumption compliance is the targeted goal in treating sleep apnea. This viewpoint is often a manifestation of the influence exerted on clinical care by insurance carriers, and in the case of sleep apnea treatment it represents a counterproductive impact. After all, the real reason to treat sleep apnea is to help someone sleep better and as result gain significant improvements in various symptoms, which in turn continues to motivate the individual to use the PAP device.

From the more obvious scenario we’ll now move backwards in terms of patient engagement with the PAP device and show many more circumstance that could be designated “CPAP failure.” If you as a sleep apnea patient appreciate these distinctions, then it may open up more options for yourself if you believe your response to CPAP is lackluster and needs a boost.

The next level down would be someone who uses the CPAP device less than 20 hours per week. Depending upon the insurance carrier, this lower level of hours may be considered non-compliant. If it were a Medicare patient not only would it be deemed non-compliant, but also Medicare would stop providing coverage for the device unless the patient continues to follow-up with the sleep center and sleep specialist to demonstrate continuing efforts to increase the number of hours of use. In this situation, the sleep specialist can easily designate this patient as a case of “CPAP failure.” What happens next thought shows great variability. If we saw a patient of this type, we would immediately schedule him or her in the sleep lab to observe whether or not there is an obvious reason for the patient’s low number of hours of use. As described in prior posts, most of these patients show objective signs of expiratory pressure intolerance (simply put: they are fighting with the pressurized airflow when they try to breathe out against the air coming in). At this point, we would declare the patient a CPAP failure and switch to a dual pressure device. In this scenario, we have never had a DME or insurance carrier reject our analysis, so the patient was able to obtain a new device.

Continuing down to the next level might be the patient whose hours of use are very low and reports ripping off the mask most nights without ever being aware of doing so. In these circumstances, there could always be some other issue (e.g. the pressure settings are too high or too low, the mask fit is poor, mask leak is high, mouth breathing is interfering with the patient’s adaptation or perhaps the patient suffers from another independent sleep disorder such as leg jerks). As you would imagine, some of these factors can be re-evaluated in a clinic appointment with the sleep specialist or a sleep technologist or both. These patients may be good candidates for a PAP-NAP wherein many of these barriers can be objectively recognized and addressed.

Still, after all is said and done, if no explanation or adjustment subsequently improves the patient’s use of the device, it would then be time to deem the case CPAP failure. At most centers, the tact would be to send the patient home with an auto-adjusting CPAP device to determine if additional information about the pressure settings will explain or resolve the problem. At our center, we never send patients home with auto-adjusting devices, because there is so much more information to be gathered with the in-lab titration where we manually titrate the auto-adjusting feature. In nearly all these circumstances we demonstrate the patients do not tolerate CPAP or even APAP very well and thus switch them to a dual pressure device.

At the next level down we find a patient who may have already given up on using CPAP despite sporadic efforts during previous weeks or months. This patient has similarities to our initial compliant patient as his CPAP failure occurred over a period of time that satisfies insurance carriers in that some effort was exerted in the attempt. However, in reality some of these patients have tucked away their devices in a closet and months or years later showed up at a sleep center for a 2nd opinion. In this instance, no data need be extracted from the device. The patient has offered that he or she stopped using the device at some point in the past. Most insurance carriers appear to accept this status as failure and would permit the patient to obtain a new device. Indeed, the original device might have been returned to the DME company months or years before the patient showed up at the next sleep center.

This previous level of low engagement is close to rock bottom, but there are also some gray areas that involve patients who are using the device somewhat, obtaining minimal benefit, but find themselves perplexed on how to proceed. These areas are gray, because some sleep facilities would only schedule a mask fitting appointment and possibly arrange for the APAP device to be sent home with the patient, the latter step implying the problem is one of “wrong” pressure, not necessarily “wrong type” of pressure.

In our experience, these two steps of mask fit and APAP device may prove wasteful or untimely, because the larger problem is the patient simply cannot get comfortable with the pressurized airflow when delivered in the continuous fashion of CPAP. Thus, the question that materializes is whether CPAP failure can be designated by a patient’s declaring continuous pressure is uncomfortable or whether instead some objective finding is needed to prove this discomfort as unresolvable with CPAP.

Consider the following examples. A patient returns to the sleep lab after months of not using the device, and at the pre-sleep desensitization before lights out, he reports CPAP is uncomfortable when he tries to exhale. He further clarifies that this sensation was the same one that prevented him from adapting to the device. So, would you declare this patient a CPAP failure? We would and do so regularly, but some insurance carriers may call for more data. These insurers probably do not know much about sleep lab operations, but it would not be surprising if they invoked some theory about how the level of comfort should be assessed while the patient is asleep not just while awake. In this instance, then, the patient must start the titration with CPAP, fall asleep with it, and then demonstrate some characteristic(s) of intolerance to the CPAP pressures. The good news is that many such patients manifest what we call, “objective expiratory pressure intolerance” or O-EPI, which simplistically indicates the patient is fighting with the machine when trying to exhale. In fact, most patients who report subjective expiratory intolerance (S-EPI), i.e. discomfort on exhalation, also demonstrates O-EPI once they fall asleep.

The prior scenario then reflects another gray area, which could lead to a final scenario(s) that may issue from this intolerance and would impact those patients who try still more advanced technology, such as dual pressure machines, and yet still fail these newer devices. The most common example would be a bilevel or BPAP patient failing due to further intolerance (S-EPI or O-EPI), which then requires a switch to ABPAP, the auto-adjusting version of BPAP. We have seen the largest majority of our patients manifest problems with CPAP, APAP and BPAP and then do noticeably better with the ABPAP device. 

In addition to reducing pressure intolerance, in patients who are responding to ABPAP therapy, we notice many other signs of enhanced sleep quality such as greater sleep consolidation, more REM sleep, fewer arousals, and self-reports of sleeping better or much better the morning-after. Notice, however, these points are not consistent with the concept of CPAP failure. Rather, they speak to the issue of improved or enhanced sleep, which of course is the desired goal of the patient. But, would an insurance carrier listen to the facts emanating from this perspective? The answer is largely unknown, because most insurance carriers and possibly related DMEs would have anticipated some report on a “negative” factor that prevents the patient from using CPAP instead of some “positive” factor on why the patient should use a BPAP or ABPAP device.

Fortunately, the negative factors are usually present, but in one of the most challenging scenarios, what happens to the patient who fails ABPAP therapy? This one is very tricky, because the next advanced device to consider would be the ASV device, yet supposedly to receive insurance coverage for adaptive servo-ventilation (ASV) you must demonstrate various outlier breathing events known as central apneas to qualify for ASV. Making it even more difficult, there needs to be a certain number of central apneas (>10), and the ratio of breathing events still persisting on the titration sleep study must tabulate to a specific ratio, such that more central apnea breathing events persist compared to the sum of any other type of breathing event.

As more people are hearing about ASV, there are probably more people hearing about the increasing difficulty in qualifying for this highly advanced device. However, this brings us to a huge caveat that both DMEs and patient must note. If a patient fails all devices except ASV—truly fails these devices (CPAP, APAP, ABPAP) under any requisite criteria of the insurance carrier—then what is the sleep center supposed to do? In our experience, when these patients do not meet criteria for the ASV device, we have still successfully prescribed this device for several patients by informing the insurance carrier the patient was physically or mentally (or both) unable to use any other device save ASV therapy. Surprisingly or not, most insurance carriers will accept this logic, albeit it may be extremely difficult to present such cases on behalf of Medicare patients, because of the built-in difficulties in communications that may arise with this government regulated insurance carrier. 

In sum, there are many facets to the concept of CPAP failure, the most important of which should revolve around a patient-centric model of care. Any of the findings described above have been known to help patients gain a new device with continued insurance coverage. But, if CPAP failure is your current status, you still may have considerable work to do in sorting how your sleep professionals and DME companies can assist you in your efforts to move on to a more advanced PAP technology.

Barry Krakow MD


Dr Krakow’s 27 years of sleep research have focused on the complex relationship between physiological and psychological sleep disorders. Dr Krakow currently operates private sleep medical center, Maimonides Sleep Arts & Sciences, Ltd., and serves as Classic SleepCare’s paid Medical Director.

Leave a comment

Comments have to be approved before showing up.