Diagnosis and treatment for obstructive sleep apnea (OSA) continue to be vital; according to the National Institutes of Health National Heart, Lungs and Blood Institute physician office visits for sleep apnea increased from 2 million to 3.7 million from 2000 to 2009.
There has been a transformation in how OSA is diagnosed and treated, however. Home sleep studies are swiftly replacing in-lab polysomnographs (PSG), automatic positive air pressure (APAP) machines are being introduced in place of traditional in-lab continuous positive air pressure (CPAP) titration studies, and surgical procedures for treatment are increasingly varied in type.
Home Sleep Studies
In 2008, CMS approved the use of home sleep studies to diagnose OSA patients and qualify them for CPAP. The majority of private insurers have followed CMS’s lead and now require home sleep tests for OSA diagnosis.
“The information you receive from a home sleep study is adequate for diagnosing patients with moderate to severe OSA without comorbidities such as heart disease or morbid obesity,” said Kathleen Yaremchuk, MD, MS, chair of the department of otolaryngology-head and neck surgery at Henry Ford Hospital in Detroit. Home studies aren’t adequate for all patients, she added, but for a large portion of the population, they’re appropriate.
Some physicians have concerns about gaps in the data that home study machines record, however. “There are different types of machines, and CMS stated that for them to pay for a home sleep test (HST) or CPAP treatment that was to follow, certain requirements needed to be met. Those requirements only referenced sleep apnea measures,” said Lee Shangold, MD, an otolaryngologist who’s board certified in sleep medicine, and a partner in New York and New Jersey-based ENT and Allergy Associates. “Most HST machines, for example, don’t measure other aspects of sleep that are routine in the sleep lab, such as periodic limb movements (PLMs). A patient with frequent PLMs may present for evaluation of excessive daytime sleepiness (EDS). If they snore, a sleep study will likely be ordered. If they do not have significant OSA on an HST, the work-up for a sleep disorder contributing to the EDS may end. However, if they were in the sleep lab and had frequent PLMs, they would then be evaluated and possibly treated for PLM disorder with resolution of the EDS.”
In addition, according to Stacey Ishman, MPH, MD, surgical director of the Upper Airway Center at Cincinnati Children’s Hospital Medical Center, affiliated with the University of Cincinnati, many home sleep studies underestimate OSA due to a poor negative predictive value. “They have algorithms that are good at picking up drops in oxygen, but there is a patient subset with partial obstruction (hypopnea) that machines may not pick up,” said Dr. Ishman. “This is why they’re not recommended for children, as most pediatric patients have hypopneas, not apneas. Home tests have a great positive predictive value, but they may not be sensitive enough to rule out OSA in people who are at low risk for sleep apnea.”
Others, like Pell Ann Wardrop, MD, medical director at the Saint Joseph Sleep Center in Lexington, Ky., and an ENTtoday editorial board member, are concerned that some insurance companies may choose not to follow CMS guidelines when it comes to the decision on when in-lab PSGs are warranted. “We really have to strongly advocate for patients, or do a home study and note that it didn’t tell us what we need for proper diagnosis,” she said.
“Overall, home sleep studies are a reasonable next step in the evolution of treatment for patients with OSA,” said Dr. Yaremchuk. “We have an aging population with an increased awareness of the prevalence of OSA, and there aren’t enough qualified sleep labs to do all of the inpatient studies we’d like to see done. However, in some ways insurance companies and the authorization process have interposed themselves into the doctor-patient relationship, and that can be problematic.”
APAP vs. CPAP Titration
The increase in home sleep studies is accompanied by the growing replacement of CPAP titration studies with APAP. Part of this upswing in use is due to a reduction of insurance payment coverage for titration studies, says Dr. Wardrop. “In the past, patients had an in-house PSG and then were brought back for a titration study,” she said, “If results were overwhelmingly positive, CPAP titration to set the pressure of the airflow on the machine was done the same visit in a split-night study.” Instead, APAP machines use a pressure range, eliminating the need for an exact titration—and, to some degree, the need to send OSA patients to the lab.
“If a patient has severe OSA, there is a way to send an APAP machine home as a therapeutic trial,” said Dr. Ishman. “We look to see what kind of pressure patients are using 90 percent or more of the time to determine a starting pressure when we transition them to a traditional CPAP. Most patients end up converting—CPAPs are less expensive, so insurance often encourages patients to switch. And although the APAP works well for some patients, others may not sleep as well with a range rather than an exact setting.”
Dr. Wardrop has seen movement toward skipping sleep studies entirely and directly moving to prescribing APAP machines to patients with a high probability of OSA. For certain patients, this can work, she said, although it may not be a good alternative for those with mild to moderate OSA.
The downside, said Dr. Shangold, is that if patients don’t do well with an APAP in the beginning of their treatment, they’re less likely to be compliant. Patients who’ve never used these machines before might go through several masks during a titration study in the lab until they find one they’re comfortable with, he added. However, if a durable medical equipment company sets them up with APAP at home during the day, they will make their best guess at the ideal mask or interface. “That first night at home using APAP, the patient may turn to the side and the mask will shift creating a leak. They may take it off and never put it back on,” he said. “I tell patients who go to the sleep lab for a titration study that by the time they leave the lab in the morning, I want them to have the most comfortable mask and an understanding of how to work with it.”
Many otolaryngologists have successfully adapted to this new paradigm, but the key is being aware of which patients don’t do well with APAP, said Dr. Wardrop. “Otolaryngologists need to review the downloaded data from APAP machines to determine if patients are being successfully treated,” she said. “If physicians have questions, they should advocate for a titration study and check to make sure there isn’t an undiagnosed condition, such as uncontrolled hypertension.”
“As long as patients are willing to be treated, we will be able to successfully treat them. However, it’s our responsibility to follow up,” added Dr. Shangold. “You can’t just give patients an APAP and then never see them back. The onus is on us as physicians to see that OSA patients are properly treated long-term for this chronic illness.”
There have been shifts in surgical treatment of OSA as well, with the realization that most adults need multilevel sleep surgery for successful therapy, including both palatal and base-of-tongue procedures.
In a recent study published in The Laryngoscope (published online ahead of print August 8, 2013; doi: 10.1002/lary.24346), Dr. Ishman looked at patterns in the types of surgery used to treat OSA and found that most were undergoing base-of-tongue surgery, that there was a significant increase in nasal and hypopharyngeal surgery, and a decrease in tracheostomy use. “Surgery performed on the uvula and tonsils can help adults with OSA, but only 40 percent were helped by performing a uvulopalatopharyngoplasty. We found that base-of-tongue surgery in combination with palatal surgery or by itself was very helpful.”
Dr. Yaremchuk believes that minimally invasive robotic surgery will continue to improve outcomes for OSA treatment, allowing surgeons to reach anatomical areas that were problematic in terms of access. “There is preliminary data on its effectiveness, but we like to see large studies. Because OSA robotic surgery has been prevalent for only a few years, we just don’t have those kinds of studies yet.” She also trials of a hypoglossal nerve stimulator to bring the tongue forward—“similar to a pacemaker for the tongue. It’s in clinical trials now, but it does show promise.”
Again, insurance coverage can play a pivotal role in surgical treatment options. Dr. Wardrop said that although many providers will pay for palatal surgery, they may not cover base-of-tongue procedures. “The situation is complicated by the fact that there aren’t high-level studies,” she added. “It’s hard to get large numbers of patients who have had the same procedures, so surgical comparison studies don’t often compare apples to apples.”
Dr. Ishman is encouraged by data on who is performing sleep surgery, however. “In our study, we saw an increase in surgery by physicians who do only a low volume of cases per year,” she explained. “This may be a sign that, in general, more otolaryngologists feel more comfortable doing these procedures now.”
“We must determine how to maintain continuity of care with patients to ensure they receive the services they need—keeping track of people, especially if they’ve received testing outside of your office,” said Dr. Yaremchuk. “Make sure you let patients know they need to follow up, and give them options when a particular therapy—whether weight loss, an oral appliance, CPAP or surgery—isn’t working.”