CPAP Failure Revisited

In prior posts, (see What is CPAP Failure and How Can I Improve my Patient's Compliance) CPAP failure has been discussed, but in my ongoing observations of how other specialists practice sleep medicine and how insurance carriers meddle in clinical practice, revisiting CPAP failure seems like a pressing issue, which should be looked at from the patient’s point of view to improve care and outcomes. I fear, however, that administrative rules written almost entirely for the purpose of cost-savings (despite being advertised as quality of care efforts) show serious potential to undermine clinical practice steps and ultimately patient care.

No one is against cost-savings. Healthcare pricing is what it is because of the odd relationships that create a tangled web between physicians, insurers, hospitals and the government. It is not unusual for DMEs as well as patients to become ensnared in this web, which again does not lead to the best possible care for a large proportions of patients.

The prime example of this entanglement is the unproven yet ubiquitous belief that CPAP is the best treatment option for nearly all OSA/UARS patients. Because of this belief, sleep medicine specialists either passively accustom themselves to working within this constrained framework, or if they see flaws in the CPAP “one-mode-fits-all” mentality, they choose to withdraw from the battlefield due to the futility in fighting against purveyors of conventional wisdom, who hold so much influence, or to be more precise, too much influence on patient care in sleep medicine.

Because CPAP is accepted as the universal pressure mode, the definition of CPAP failure is usually not something the majority of sleep medicine specialists ponder with great depth. Sleep doctors have their hands full treating patients and do not recognize an easy way to negotiate new ways of looking at CPAP failure for the betterment of their patients. To be fair, there is no strict definition of CPAP failure, but as alluded to in the first paragraph, my concern is that restrictive definitions may be on the horizon, which if enacted would greatly affect OSA/UAR patients who struggle to use PAP in the early going.

To take a prime example from recent history, consider the changes in the qualifying rules for ASV. Up until just a few years ago, I do not believe there were any formal criteria for the diagnosis of complex sleep apnea. For a fair number of patients, it was obvious traditional forms of PAP such as CPAP or APAP might trigger central apneas and that seemed sufficient to warrant consideration for an ASV device. Some sleep professionals simply prescribed the ASV device with default settings, whereas others brought the patient into the sleep lab for an ASV titration study. During these titrations, we were instructed by ASV vendors to use the default settings for a while so the machine could more accurately sense the “rhythm and depth of the patient’s breathing.” Nonetheless, after the first 30 to 60 minutes, the sleep technologist was advised to conduct a manual titration, albeit it was (and may still be) quite confusing as to how to change the various pressure settings on an ASV device, not to mention what it actually means when changing these settings. More on that story another time. 

As more ASV devices were prescribed, suddenly you know who (Medicare) came up with rigid criteria for ASV in which the patient needed to demonstrate at least 10 central apneas, and the ratio of the CAI over the AHI (i.e. CAI/AHI) needed to be greater than 50%. In other words, the central apneas needed to be the predominant breathing event emerging while treated with CPAP. Obviously, many sleep professionals would be likely to first attack this problem with BPAP, because many years ago bilevel devices were advertised as a possible treatment mode for central apneas. Nevertheless, ASV is clearly superior to a traditional BPAP mode, and some would argue ASV is superior to the newer forms of BPAP ST, another device to treat central apneas. However, ASV is also one of the most costly devices on the market, which no doubt factored into Medicare’s decision-making to make it more difficult for patients to qualify for the device. 

Unfortunately, for patient care, Medicare officials do not really understand that much about ASV technology in that they believe its only use is for patients with central apneas. As we have described in research abstracts and published papers, central apneas are often a signal or marker of patient discomfort, subjective or objective. This type of discomfort shows up more subtlely in the form known as expiratory pressure intolerance or EPI. This EPI problem is extremely common in CPAP users, and future research is very likely to prove ASV therapy as an outstanding treatment for EPI. Thus, in an ideal health system, governed by science and not bureaucracies, ASV would probably successfully reverse CPAP failure in tons of patients. Right now, however, very few people in sleep medicine talk about this use of ASV, and the vast majority of sleep specialists do not envision any way to fight against Medicare rules to qualify for ASV. When rules become constrained, physicians often are intimidated or simply unmotivated to “fight city hall,” and so even among their patients with central apneas, there may not be any drive to help them receive an ASV device.

Now back to CPAP failure. Given all the cost-consciousness with CPAP, I am concerned that more stringent rules will be adopted. For example, if Medicare has gone so far as to insist you must use PAP 5 nights (actually 4.9 nights) per week for 4+ hours on the nights used to achieve compliance, why would we be surprised if the rules continue to be adjusted to make criteria for coverage more stringent? Why not 6 nights per week or why not 5+ hours per night? After all, if Medicare needs to save money, the short-term picture would have them believe fewer people using CPAP devices is a cost-savings, despite the knowledge long-term use of CPAP reduces hospital stays and lowers medical costs.

From a patient’s point of view when encountering PAP therapy in the environment of a sleep lab, CPAP failure is actually quite obvious to detect, but taking into account all the things described above, the question of concern is whether or not new rules will make it more difficult to “fail” patients and thereby make it more difficult to switch them to another technology such as BPAP, ABPAP, or ASV.

In the sleep lab, even during a presleep desensitization procedure, CPAP fails when the patient cannot tolerate the fixed pressure when attempting to exhale. Some patients report discomfort during this experience, but others report so much distress, they develop panicky or claustrophobic sensations and rip off the mask. There is a huge proportion of sleep doctors that seem to think these patients will simply get used to the fixed pressure of CPAP; they are of the opinion the patient should still be titrated on the CPAP device in the lab and then prescribed it for use at home despite this discomfort. At our lab, we presume patients’ distress is a signal for likely future adaptation difficulties. We may still attempt CPAP during the titration, but if the patient again reports this discomfort or intolerance to fixed pressures or if we see the objective EPI on the airflow tracing, we know it is time to switch to another device to provide immediate relief for the problem. 

We are perplexed that some sleep professionals strongly believe these patients will adapt to CPAP over time. In contrast, we wonder whether this discomfort is a major factor in the depressing rates of CPAP adherence. In a research paper just accepted for publication in Respiratory Care, we report on our center’s very high rate of PAP use (87%) among patients with greater susceptible to adverse reactions to pressurized air flow, and all patients were prescribed BPAP, ABPAP or ASV. We hope this research spreads to other sleep centers to show how CPAP failure can be rapidly addressed.  

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.

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