A 56-year-old man comes to the clinic for treatment of obstructive sleep apnea (OSA). He was diagnosed in 2018 when he had sleepiness and trouble concentrating. He’s tried continuous positive airway pressure (CPAP) with a full face mask and nasal pillows, but it wasn’t successful. He sleeps on his back, does not have insomnia, and uses the Oura Ring on most nights to track
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May 2024his sleep.
The man, who is white, has a history of mild high blood pressure and acid reflux. He had an uvulopalatopharyngoplasty (UPPP) and hyoid suspension a year before but is now well healed. In the 2018 sleep study in which his OSA was diagnosed, he had an apnea–hypopnea index (AHI) of 27.
How should he be managed now, and how do the Oura Ring and other devices fit into the management plan?
A panel of experts here at the Triological Combined Sections Meeting discussed advancements in wearables and other technology that can help clinicians treat patients’ sleep-related disorders.
Sleep Tracking Apps and Devices
Many apps and wearable devices are aimed at analyzing sleep patterns. For example, the SleepScore app sends and receives sonar signals, similar to the echolocation used by bats, to sense breathing and body movements and give an estimation of sleep stage data. Sleep Cycle is an app that produces similar data, but in a more graph-driven way, and uses the smartphone’s microphone to detect breathing sounds. It can also detect movement with an accelerometer when the phone is left face down on the bed.
As for wearables, smart watches like the Apple Watch and fitness trackers like the FitBit include accelerometers and gyroscopes that can track motion and breathing. Some use the infrared light technology photoplethysmography (PPG), which uses light that can penetrate the skin and do a volumetric analysis of blood vessels to track heart rate and oxygen saturation.
The Oura Ring, touted by celebrities in part for its aesthetics, provides data on sleep cycles, sleep time, temperature, oxygen saturation, and heart rate and works with an app to give a sleep score.
The Muse S brain-sensing headband, another option, uses electroencephalography data, PPG, and an accelerometer to track sleep. There are also “wearables” that you sleep on, like the Withings sleep tracking mat, which tracks sleep cycles, breathing, heart rate, and snoring, and gives a sleep score.
Technology Interventions for Sleep Problems
Other technological advancements aim to improve sleep positioning. In addition to pillows, belts, and other supports to encourage side sleeping, vibrotactile devices worn around the chest or neck can sense when someone is sleeping on their back and use a gentle but persistent vibration to remind people to change their position.
In the case of the man with OSA who failed CPAP, a new post-op sleep test found that his AHI had worsened somewhat. He was prescribed positional therapy, with a recommendation that he sleep on his side rather than his back. Unfortunately, positional therapy was not successful for him on most nights. He underwent drug-induced sleep endoscopy (DISE) and was a candidate for hypoglossal nerve stimulation (HGNS).
The technology for HGNS—in which mild stimulation is delivered to the hypoglossal nerve, which innervates key airway muscles for better breathing during sleep—was introduced about 20 years ago, said Maria Suurna, MD, professor of clinical otolaryngology–head and neck surgery at the University of Miami Miller School of Medicine. Since its FDA approval in 2014, the technology has continued to evolve. Initially, the therapy was implanted through three incisions; it is now a two-incision procedure. The respiratory sensor is now shorter and sturdier, which has meant fewer complications related to respiratory sensor failure, she said.
Advancement in the procedure for electrode cuff placement has worked to prevent “mixed activation.” Proper tongue movement, which will open the airway optimally, depends on the precise placement of the cuff on protrussor branches of the nerve, excluding all retractor branches. Sometimes, the cuff is placed in a way that causes tongue retraction because a small retractor branch was not identified during the dissection and is trapped in the cuff, which is a bad outcome, Dr. Suurna said. But she and others have developed protocols involving neurophysiological monitoring of the activation of the tongue muscle during the operation, to make sure the placement has the desired effects, she said (Laryngoscope. 2020;130:1836-1843).
“The whole goal is to have forward unrestricted motion of the tongue,” she said. “Unfortunately, if you’re not precise with placement of the stimulation cuff, you’ll have mixed activation.”
A few months following the procedure and therapy activation, some patients might be unable to continue with the HGNS therapy because of discomfort. Dr. Suurna said adjustments can be made to the stimulation parameters to help in situations like this. Changes to the polarity, amplitude, pulse width, and pulse rate can make the stimulation more tolerable, she said. This can be done in the office setting, often while visualizing the airway with a laryngoscope and assessing the effects of the adjustments and the patient’s response.
“One of the mistakes I think that people make is that they use the CPAP-type model, where the more pressure, the better, while more stimulation does not always mean it’s better,” Dr. Suurna said. “People can only tolerate so much when it comes to activation of the muscles…. If it starts becoming too strong and disrupts their sleep, it becomes counterproductive.”
Web-based application monitoring of OSA treatment quality measures allows clinicians to see how many hours per night the therapy is being used and how often a user pauses the therapy. If that happens often, physicians can then assess whether there is a problem with the device or whether it’s a matter of patient sleep hygiene.
Other advancements on the horizon, Dr. Suurna said, include bilateral HGNS—which is placed through one incision and is now available in Europe—and ansa cervicalis stimulation, which, in combination with HGNS, seems to decrease the collapsibility of the pharynx and improve airflow (J Appl Physiol. 2021;131:487-495).
Pediatric Applications
Taher Valika, MD, assistant professor of otolaryngology at the Northwestern University Feinberg School of Medicine in Chicago, who specializes in pediatrics, discussed the case of a seven-year-old boy with trisomy 21 who presented for primary snoring. He had not had polysomnography and had classic symptoms of OSA.
Resources for getting sleep studies in children can be scarce, and parents might be hesitant to have sleep studies performed on their children. At Northwestern, Dr. Valika and others have developed a label-like device that sticks to a child’s forehead and measures breathing rate, temperature, movement, and other things. It has been validated in NICU patients.
“The goal of this current work is to validate our wearable hybrid technology to see if we could use it with our polysomnography labs,” he said.
In the Northwestern case, the child was not able to tolerate a sleep study. DISE might be an option, Dr. Valika noted. While the indications in children are evolving, he said, most physicians agree it is appropriate for those with persistent OSA after tonsillectomy and adenoidectomy.
Glossoptosis is often found to be the primary cause of airway obstruction during sleep in patients after adenotonsillectomy. HGNS is not indicated for all children, but a procedure for tongue base suspension Dr. Valika has developed, in which fluoroscopy is used for guidance, can be effective, he said.
A study found that, among 31 children who were medically complex—with trisomy 21, cerebral palsy, and hypotonia—the procedure produced substantial improvement in OSA, with a 75% decrease in overall AHI. Twenty-three of the children had been referred for a tracheostomy, but most haven’t needed it, he said, an indication of the success of this approach (Laryngoscope. 2021;131:2112-2114).
“Twenty-one out of the 23 didn’t get a trach,” Dr. Valika said, “and they still don’t have a trach three years later.”
Conclusion
While sleep technology apps and wearables can be tempting for patients eager for a good night’s rest, otolaryngologists should temper that excitement with realistic expectations about what the technology can—and can’t—do. “I think it’s incumbent on us as providers to make sure that patients understand that these apps cannot offer a truly accurate sleep analysis in the same way that a sleep study can,” said Reena Dhanda Patil, MD, professor of otolaryngology–head and neck surgery at the University of Cincinnati. “But they can provide valuable information in terms of tracking sleep trends and patterns and allowing the patient to become a little more educated on what’s happening on a night-to-night basis.”
Thomas R. Collins is a freelance medical writer based in Florida.