Treating Obstructive Sleep Apnea: AASM Releases Guidance for Follow-Up Sleep Studies

Sleep physician Meir Kryger, MD, FRCPC, who was not involved in creating the guidelines, says he would eventually like to see more guidance on whether any of the consumer devices available that measure blood oxygen or sleep might be used in this context.

Says Kryger, a professor at Yale University, “A lot of people are getting oximeters and other devices that monitor sleep and it would be useful to know whether follow-up with those kinds of instruments would turn out to be valid. There is no data on that and it would need to be studied in detail.”

The fifth statement relates to cardiovascular disease and its strong link with OSA. A systematic review of the literature found no direct evidence to guide if and when follow-up testing should be performed in individuals with cardiovascular disease, but it could be considered in certain clinical situations, including systemic hypertension, heart failure, cardiac arrhythmias, and stroke.

“If someone has had a stroke or developed heart failure, those are excellent indications for re-evaluations because both of those can affect the type of apnea and the severity,” Kryger says.

The sixth statement maintains that follow-up PSG may be used in the case of unexplained device-generated data. Automated event detection obtained from a positive airway pressure device may be considered in the decision to perform follow-up PSG or HSAT, though the authors caution that such data comes from proprietary software so is of uncertain validity. They say follow-up PSG may be warranted based on automated event detection when device software shows the residual apnea-hypopnea index (AHI) remains elevated, particularly in the face of symptoms. 

Zachek says, “I do pay attention to the AHI that is generated. There are circumstances where this prompts me to move to a more sophisticated device, for example, an ASV.”

The statement also addresses a controversy around treatment-emergent central sleep apnea. Evidence for this condition on PAP download (a high central apnea index) could represent an indication for repeat testing. Since treatment-emergent central sleep apnea dissipates over time in a sizable number of patients, the authors say repeat testing should occur after a minimum of three months of PAP therapy.

“The significance of treatment-emergent central sleep apnea is a matter of debate, so it’s difficult to make firm recommendations,” Caples says. “This statement highlights the uncertainties but also gives some guidance on navigating an approach.” 

Zachek notes a practical need for a patient to undergo a repeat sleep test, though not necessarily a clinical reason. “The other reason we might think about a repeat study is the inability to locate a study done in the distant past. Many patients change location and durable medical equipment providers. When requesting updated supplies and/or a new machine, a repeat study is sometimes necessary to satisfy insurance,” he says.

Overall, the guidelines contain no surprises.

“What they’re summarizing is what people have learned to do anyway,” Kryger says. “All of these things people have actually been doing for the past few years, as in, we no longer do follow-up studies on patients on CPAP who are doing well clinically. It’s nice to see that this has now been carved in stone.”

Ojile says, “The guidelines give us the intellectual framework to have these discussions and gives a rationale for the utilization of certain follow-up tests. For those who aren’t doing well on PAP therapy, we need them to come into the lab to study them.”

Jane Kollmer is co-owner of Ch/At Communications, which provides writing and editing services to clients in the healthcare and travel industries. 

Reference

Caples SM, Anderson WM, Calero K, et al. Use of polysomnography and home sleep apnea tests for the longitudinal management of obstructive sleep apnea in adults: an American Academy of Sleep Medicine clinical guidance statement. J Clin Sleep Med. 2021;17(6):1287–93.

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