Expert Insight - Polysomnography

I am currently working with a Dr. Kathy Richards who is conducting a study using PSG. We want to find out about the recommended standards for grading a PSG. Apparently there is an alternate form of scoring and a standard form of scoring. Which form of scoring may come under scrutiny with Medicare? Which form is widely accepted and unlikely to com under scrutiny? -

I am familiar with some of the work from Dr. Richards related to sleep and aging. Your question is of course related to a research application and to acceptability in peer-reviewed publication, rather than a routine clinical focus. Your question is broad enough to cover several topics regarding PSG scoring, sleep staging, and various event detection and identification processes. Currently there are two approaches to staging sleep studies that have been used routinely. For many years that standard for staging sleep was the Rechtschaffen and Kales manual (R&K) on staging sleep published in 1968. The vast majority of published studies have used this method. With many advances in technology and in understanding the sleep-wake continuum, the AASM convened a task force to review and propose new PSG scoring guidelines. The Task Force published the new AASM Manual for the Scoring of Sleep and Associated Events in 2007 (available through the AASM website www.aasmnet.org). They recommended changes in the channels to record for sleep staging and in the rules for deciding the sleep stage of an epoch (30 seconds) of recorded data.

Identifying and scoring events associated with a PSG, including respiratory events, limb movements, arousals, and cardiac events have also had several different sets of standards published are various times over the years. With the development of better sensor technologies, the AASM Task Force made recommendations that monitoring for respiratory events include inductive respiratory bands, nasal pressure sensors, and thermal airflow sensors, as well as adequate pulse-oximeter devices. Alternative rules for scoring one type of respiratory event, hypopnea, have been accepted primarily because published results from the Sleep Heart Health Study demonstrated that a 4% desaturation with hypopneas (with a 30% or greater reduction in effort or airflow) were associated with increased incidence of hypertension, cardiovascular disease and reduced quality of life. Medicare subsequently implemented this rule in its guidelines for AHI calculated to qualify for CPAP therapy. The alternative allowed by the AASM requires a 50% or greater reduction in effort or airflow with either a 3% or greater oxygen desaturation or a terminating arousal.

The background articles from the Task Force may be found in the Journal of Clinical Sleep Medicine (Journal of Clinical Sleep Medicine, Vol. 3, No. 2, 2007).

What will CMS accept? They will accept either the R&K or the new AASM criteria for sleep staging. For respiratory events, CMS does define a hypopnea as respiratory event lasting a minimum of 10 seconds with at least a 30% reduction in movement or airflow accompanied by a drop in oxygen saturation of 4 percentage points or more. As with all research, document the criteria you use to score events to allow for comparison with other studies.

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Can our neurologist office perform sleep studies in a office that has 100 square foot bedrooms set up with bathrooms? Does the neurologist have to be board certified in sleep? A registered polysomnographer will perform the study. -

The short answer is yes, the neurologist may perform sleep studies in his/her office as an extension of their practice. But adding these services requires due diligence in compliance with regulatory requirements to ensure services are covered and reimbursable.

When a physician considers adding sleep diagnostic testing as an extension of their office practice there are several business related questions that will determine the requirements for the facility. The most critical decision is whether services will be provided to patients covered by Medicare or Medicaid. If yes, this adds some very specific requirements. Current CMS requirements can vary depending on the region of the country where you operate.

In California, the Local Coverage Determination (LCD) is set by the Medicare Contractor, Palmetto GBA; their current LCD on Polysomnography and Sleep Studies can be accessed here: http://www.cms.gov/medicare-coverage-database/details/lcd-details.aspx?LCDId=27589&ContrId=171&ver=32&ContrVer=1&CntrctrSelected=171*1&Cntrctr=171&name=Palmetto+GBA+(01101%2c+MAC+-+Part+A)&s=6&bc=AggAAAIAAAAA &

If the facility intends to apply for accreditation through the American Academy for Sleep Medicine (AASM), there are additional specific requirements that need to be met, including the size of patient bedrooms--the standards have become more flexible and there no longer is a required minimum square footage. The current AASM standards for sleep labs can be downloaded from http://www.aasmnet.org/accred_centerstandards.aspx

Several third-party insurance payers may also have requirements for accreditation or board certification of the physician; so a review of their coverage policies is important when deciding to add these services.

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How much growth will home sleep testing market have over the next couple of years? -

Home sleep testing (HST) is an established and growing component of the evaluation of sleep disorders, specifically obstructive sleep apnea. Medicare has approved the use of HST for the qualification of patients with suspected OSA for treatment. Other third-party payers have been changing their guidance directives to not only approve the use of HST, but in some cases to require HST as the initial diagnostic evaluation. So home studies are here to stay and will become a significant part of the diagnostic processes in evaluating people suspected of having sleep disorders.

Though there is ample evidence to document that HST is an appropriate and effective diagnostic tool in patients whose symptoms are consistent with and suggestive of obstructive sleep apnea, there is recognition that patients with any of several complicating factors should be tested in the sleep lab.

That being said, it is the expectation that all sleep labs should add home sleep testing services to their operations.

The guidelines for providing home sleep services allow primary care physicians as well as many specialists to perform this testing. It is a requirement for Medicare and some other insurers that the study results are interpreted and reported by a physician who is board certified in Sleep Medicine.

With the increased use of home sleep testing to confirm obstructive sleep apnea, treatment options will continue to evolve. Auto-titration PAP systems can certainly have a place in providing treatment. The expanded involvement of primary care physicians in the evaluations of sleep disorders should be welcome, as it will result in more patients with sleep disorders being evaluated, diagnosed and treated. There is a concern, which is shared by some that primary care physicians may pull patients away from the sleep centers. I believe that this is a great opportunity for the sleep centers, which have a concentration of expertise in managing the care of patients with sleep disorders to build relationships with the primary care physicians who are involved with home sleep testing programs. In my experience, most primary care physicians will want to refer their patients to a qualified expert for the ongoing management of their sleep disorders--creating a referral relationship with the primary care physicians is important.

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I was in the military from 1972 to 1992 and am an African-American male. In your medical opinion, would anyone be able to diagnose me with a sleep disorder and would weight be a risk factor for me being African-American? -

First I want to thank you for your service to our country. As far as being diagnosed with a sleep disorder, the place to start is with your primary care physician and discuss your symptoms and concerns. A referral to a physician who specializes in sleep disorders may be appropriate and depending on the evaluation, a overnight sleep study may be warranted. Excessive weight is a definite risk factor for some sleep disorders, such as obstructive sleep apnea, regardless of racial heritage. If you are overweight, then weight loss could definitely reduce the risk for sleep apnea or even reduce or resolve snoring, which may be disruptive to your sleep or to a partners sleep.

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Are there any reviews of users of the PROVENT device and if so how can I access them? -

The Provent nasal EPAP unit from Ventus Medical is a unique device that has been shown to be effective in many patients with mild to moderate sleep apnea. Several published studies have demonstrated effectiveness, though as with many non-CPAP treatment, the majority of papers can be accessed from the Ventus Medical website: http://www.proventtherapy.com/hcp/nasal-epap-clinical-information.php . A few patient testimonials are also available for viewing on the website.

Dr. Meir Kryger, one of the researchers who have published on the device has stated that the device works well in many patients with mild to moderate OSA, even some with severe OSA. Currently, it remains a second line of treatment, in part because of limited reimbursement. Two groups that it will not work well with are patients who sleep with their mouth wide open (since the device relies on nasal breathing to operate) and those who have nasal obstructions (deviated septum, tissue hypertrophy, allergic nasal congestion) (Source: personal communication).

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Hi, I have CPAP aerophagia. Beyond bloating in stomach, it has reached my neck, arms, and legs. I feel like my head is going blow off at any time. It sounds like whistling wind when releasing pressure. I've been on several machines and all masks over the last 16 years. Please can you help. Any suggestions welcome. -

Aerophagia related to CPAP treatment is not common, but it does occur. An excellent review article presenting some of the more recent scientific thought on the cause of aerophagia was written by Regina Patrick, RPSGT, in the October 2010 issue of Sleep Review.

In this article, the work of Watson and Mystkowski showed that abnormal function of the upper and lower esophageal sphincters, often associated with gastroesophageal reflux disease (GERD) may be a major cause of this condition. (Watson NF, Mystkowski SK. Aerophagia and gastroesophageal reflux disease in patients using continuous positive airway pressure: a preliminary observation. J Clin Sleep Med. 2008;4(5):434–438.)

Suggested methods for reducing the aerophagia include body position (head inclined), limiting food consumption prior to bed (reducing GERD), reducing the mean positive airway pressure may help, and some have advocated a switch to APAP systems, which sometimes produce lower mean airway pressures.

Another option to consider is to work with a dentist to produce an oral appliance to advance the mandible (lower jaw bone), which may either allow you to forego CPAP altogether or it may allow the CPAP pressure to be lowered to a point that reduces the incidence or severity of the aerophagia. Look for a dentist who has specific training in applying oral appliances in sleep apnea and is willing to work with your sleep physician in adjusting your CPAP treatment level.

Good luck.

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When scoring N2, N2, N2 w/arousal (arousal occurring in last 5 sec of epoch), W, W, W, versus scoring N2,N2,N2 w/awakening (everything same as above), W, W, W, which is correct arousal or awakening? It shows up on the report as one or the other. I can't find criteria for "awakenings versus arousals." If they stay awake, I score it as awakening. If it's just an arousal and they keep sleeping, I score it as an arousal. Is this correct? -

Yours is a common concern when learning to implement the new scoring rules. There are two issues here that interact, sleep stage and arousal.

Let’s address the arousal definition first. The rules state that an arousal is scored if the EEG frequency shifts for a period of at least 3 seconds when preceded by at least 10 seconds of stable sleep. This could occur during any portion of the 30 second epoch, even the very first few seconds, if the last 10 seconds of the previous epoch demonstrated sleep.

As I am sure you know, scoring an epoch Wake requires that more than 50% of the 30 second epoch show alpha rhythm, eye blinks, in-phase rapid eye movements, and often elevated chin EMG. Since the rule requires more than 15 seconds of this activity to score the epoch Wake, it is entirely possible to have an epoch that is scored Wake, but also having an arousal. For example, the first 16 seconds demonstrate alpha rhythm, followed by 11 seconds of sleep, with a shift in EEG frequency the 3 seconds. In this case the arousal is scored, if the next epoch is scored Sleep (N1-3 or R).

What is not clearly stated, but can be inferred from these two rules, is that arousals that last longer than 15 seconds are indeed considered awakenings. So in your example, if the arousal event extends across two epochs, but lasts less than 15 seconds, it should be scored as an arousal. If the arousal lasts longer than 15 seconds and the next epoch is scored Wake then you definitely have an awakening.

So your ‘rule-of-thumb’ that, “If they stay awake, I score it as "awakening"… and, If it's just an arousal and they keep sleeping, I score it as an arousal,” is useful. I hope this is helpful.

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