By Barry Krakow, MD
The PAP-NAP, a daytime desensitization and mini-titration procedure to help patients adapt to positive airway pressure therapy (PAP-T), has drawn much interest from the sleep medicine profession. Many sleep professionals have contacted Maimonides Sleep Arts & Sciences with questions about the procedure. These inquiries unexpectedly led to discussions about several problematic sleep lab practices, which from our perspective pointed to missed opportunities to optimize PAP-T adherence and outcomes.
In the 7 years since first conducting PAP-NAPs and in the intervening years of training others in the technique, we identified five overlapping problematic practices likely to hamper efforts to optimize sleep apnea treatment, whether with a PAP-NAP, a titration, or a retitration study. The term “overlapping” is key, because it was routine to observe all five factors affecting any given patient, suggesting a herding effect. These problematic practices tend to arise in order:
- Underscoring or ignoring flow limitation on the airflow signal (pressure transducer input) for either diagnostic or titration studies.
- Not recognizing expiratory pressure intolerance caused by fixed pressure CPAP or BPAP devices.
- Adhering to conventional wisdom that fixed CPAP works for most patients.
- Discounting technological advances in the newest auto-bilevel (ABPAP) and adaptive-servo ventilation (ASV) devices, which when manually titrated in the sleep lab may generate results physiologically superior to fixed CPAP or BPAP devices.
- Assuming a defensive posture on whether to return sleep apnea patients to the lab for repeat titrations in spite of complaints about adherence or outcomes.
To demonstrate the ubiquity of these points, our experience at Maimonides Sleep Arts & Sciences provides useful anecdotal information. We receive second opinion cases at least twice per week from within and outside of New Mexico, averaging more than 100 dissatisfied sleep apnea patients per year. In most second opinion cases in the past 3 years, we confirmed that flow limitation events had not been scored, expiratory pressure intolerance was overlooked, and CPAP was the only device ever prescribed, because these sleep apnea patients were informed no other device would prove superior. And they were explicitly or implicitly informed that repeat titrations offered no benefits, or their insurance company would not cover another “sleep test.”
This statement about insurance coverage is widely misinterpreted as far as we can tell as it relates to the concept of medical necessity. Sleep apnea patients who have not attained standards of adherence or outcomes would “reasonably” and “necessarily” undergo a repeat titration treatment to fix the problem. And they would undergo this procedure when the sleep physician deemed it necessary, not when some arbitrary insurance timeline dictated. However, it seems that the current climate in health care pushes the viewpoint that “sleep tests” are used excessively, which would no doubt influence providers to forego the procedure.
THE ROOT OF THE PROBLEM
Surprisingly, a root element of these barriers to optimal care was simply the implied acceptance of health insurance terminology that depicts titration studies as “sleep tests.” When imagining all that transpires during a titration or retitration study, including the PAP-NAP, we use “treatment procedure” as the more informed term.
This distinction is not semantics. “Sleep test” connotes active gathering of information like any other lab test, so the term fits a diagnostic study. Although a titration collects data too, the chief purpose of this “test” is to optimally treat the patient’s sleep apnea. Just as cardiac angioplasty opens a coronary artery, a titration treatment procedure opens the airway. One increases blood flow, the other increases airflow, and both are most effective when they open the passageway as much as possible. Angioplasty is not a test; it is a treatment or intervention procedure. The same holds for a PAP-T titration. Sleep professionals conduct titrations, retitrations, and PAP-NAPs to treat (not test) our patients in order to open up their airways to “normalize airflow.”
In contrast, the mind-set we observed among some sleep physicians and technologists seemed skewed toward a “sleep test” perspective, and there were noticeably divergent viewpoints on the objective to “open up the airway to normalize airflow.” Moreover, we repeatedly heard a defensive chorus about titrations that aligns with what we know to be embedded in the latest Medicare efforts to count up frequencies and proportions of “sleep tests.” For these reasons, we are persuaded that this terminology and the defensive perspective it fosters yield a passive approach to titrations instead of an active one.
FROM PASSIVE TO ACTIVE
Our center also wrestled with the problematic practices described above, including concerns about ordering excessive sleep tests. Shortly after opening our sleep center, we were most fortunate to have developed the PAP-NAP because of the rich educational environment it offered to help us rethink our approaches toward titration treatment procedures.
I fondly recall many days when our tech control room was full of staff as we mulled over the sensor signals while observing patients switched from CPAP to BPAP to ABPAP, all in the space of 90 minutes. But the most indelible memory was connecting the dots between patient discomfort and expiratory pressure intolerance. To watch a patient struggle with CPAP subjectively and observe the subtle disruption on the expiratory limb of the airflow signal drove home to us the necessity for expiratory relief in a much larger proportion of patients than we had previously imagined.
As these insights emerged, we elected to start with the PAP-NAP for many second opinion patients because of their frustrations from previous lab or clinical encounters. Some described their experiences in other labs as traumatizing, while others never attempted PAP therapy at home due to just one poor night with the device. During their PAP-NAPs, we spotted the persistence of flow limitation at their prescribed CPAP pressures as well as irregularities on the expiratory limb of the airflow curve consistent with pressure intolerance.
While the PAP-NAP recording time averages slightly less than 2 hours, it was of sufficient duration to switch patients to advanced devices and manually fine-tune the pressure settings of ABPAP or ASV to attempt to normalize both the inspiratory and expiratory limbs of the airflow curve. Subsequently, all these patients returned to the sleep lab for a full night retitration treatment procedure, and some required multiple retitrations over a 3-month period due to nearly intractable nonadherence. We were pleased to see many of these patients attain our adherence goals of sleeping with the device all night, every night.
INTEGRATING PAP-NAP AND TITRATION TECHNIQUES
Although it remains uncommon to determine definitive PAP-T pressures during the daytime desensitization procedure, the PAP-NAP still serves as a mini-titration experience, which often functions as a refined segue to the patient’s next procedure—the full night titration experience. Moreover, the PAP-NAP can rapidly identify problems that foreshadow barriers that may emerge during the full night titration such as central apneas, mouth breathing, nasal congestion, and, of course, adverse mental or emotional reactions.
By maintaining an optimistic mind-set about PAP-NAPs and titrations, the sleep technologist (supported by the sleep physician) has an opportunity to work through a number of barriers during either a PAP-NAP or a full night titration, and we think sleep professionals will be impressed by how mental factors such as anxiety, panic, or claustrophobia diminish when physiological elements improve. In fact, when a patient reports immediate improvement in comfort just by changing to advanced pressure technology, this improvement is corroborated by more normal-looking airflow.
PUTTING IT INTO PRACTICE
The list below matches the problematic practices described above, but in this version we provide more focused steps to overcome these barriers:
- Maximize efforts to understand and monitor flow limitation events (30-second epochs enhance precision in viewing, scoring, and titrating, whereas 60-second or greater epochs hide more than they reveal). There is nothing to suggest flow limitation is normal unless it occurs rarely on the tracing. Fine-tune the titration process to eliminate flow limitation.
- Recognize subtle expiratory pressure intolerance as a treatable condition. Be wary of the conventional wisdom that argues it will dissipate spontaneously over time.
- Learn how advanced auto-adjusting devices when titrated manually in the sleep lab show greater potential to normalize the airflow signal on inspiration and expiration unlike what is typically seen with CPAP. The most efficient way to understand normal is to bring one or two normal sleepers into the lab. Observers will see that both inspiratory and expiratory curves are fully rounded nearly the entire night, which is identical to the optimal response seen with a PAP device.
- Create a program that encourages repeat titrations and PAP-NAPs to investigate and overcome physical, physiological, and psychological barriers to PAP adherence. Any patient falling short of standards for adherence or outcomes potentially meets the medical necessity test for a retitration treatment procedure. Sleep professionals may be surprised at how often a PAP-NAP is more useful to solve specific problems (eg, mouth leaks) than the full night in the lab.
- Develop a positive and assertive attitude about promoting hands-on experiential approaches (PAP-NAPs and titrations) as one of the most direct and paradoxically cost-effective ways to fix problematic masks, pressures, and pressure delivery systems. Once normalizing the airflow signal becomes the target of therapy, expect to see greater adherence and improved outcomes.
EXCESSIVE TESTING OR MEDICALLY NECESSARY PROCEDURES?
We have heard some criticism about the use of advanced devices and our recommendation to return the patient to the sleep lab as early and as often as necessary to overcome PAP therapy barriers. Given that our current adherence rate is 85% among patients prescribed a device and that the overwhelming majority of our patients report “good” to “very good” outcomes, our system appears to be a successful and beneficial program, especially in the context of our center’s predominant focus on mental health patients with insomnia and sleep-disordered breathing.
In our opinion, this level of success compensates for what might be perceived as excessive use of the sleep lab; but to reiterate, we do not think a repeat titration treatment procedure is excessive for PAP nonresponders. We consider it a medically necessary intervention, and in our view, failing to deliver this treatment when needed is substandard care. Moreover, long-term PAP responders decrease their own health care costs over time, which by the numbers suggests a few extra “tests” are a small down payment on excellent long-term efficacy and concomitant health savings.
Taken together, the PAP-NAP has not only added an important new way to work with our patients, but its regular use has transformed our treatment and coaching programs to help achieve the goal of using PAP therapy all night, every night. The program has also proven most satisfying to our sleep technologists because of the opportunity for an extended one-to-one patient encounter. The PAP-NAP was a singularly useful (but not the only useful) tool for trying to solve compliance problems among individual cases. It was also an instructional tool that helped us further elaborate our opinions in combination with what we were seeing during nighttime titrations.
Barry Krakow, MD, is the author of Sound Sleep, Sound Mind, principal investigator at Sleep & Human Health Institute, and medical director at Maimonides Sleep Arts & Sciences Ltd (www.sleeptreatment.com), and blogs at www.sleepdynamictherapy.com. He can be reached at firstname.lastname@example.org.