Positive air pressure can reduce sleep apnea symptoms, but only if patients actually use their PAP machine. Studies suggest that between 29% and 83% of patients fail to use their machine at least 4 hours per night. And among those who do use PAP, mean usage is just 4.5 hours per night.
“Given that CPAP usage is variable, oxygen may be an acceptable alternative for some patients,” said Vaishnavi Kundel, MD, Assistant Professor of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai. “Nocturnal oxygen has been investigated as a potential treatment for sleep apnea for over 20 years.”
Dr. Kundel opened Cases in Sleep Apnea That Keep You Up at Night with a look at the evidence for and against supplemental oxygen (SOX) as an alternative to positive air pressure. The session is available on demand for registered CHEST 2021 attendees through October 1, 2022.
CPAP withdrawal trials show that SOX can reduce hypoxemia and blood pressure in obstructive sleep apnea, but has no effect on recurrent arousal. SOX brings little improvement in sleep quality or daytime sleepiness. Small trials in central sleep apnea suggest that SOX may improve periodic breathing and AHI, but there are no large-scale, randomized, controlled trials.
“The jury is still out on the use of SOX in sleep apnea,” Dr. Kundel said. “But it is reasonable to consider in patients who are intolerant of PAP.”
A more effective approach for many patients is to help them improve PAP adherence. More hours of use are more effective.
“There is a dose relationship between CPAP use and reduction of symptoms,” said Sara Pasha, MD, Assistant Professor of Medicine and Medical Director, University of Kentucky Sleep Disorders Center. “We must individualize our approach to adherence to each patient.”
PAP use patterns are usually set during the first week of use, she continued. Patients who perceive the importance of sleep disordered breathing, self-refer for treatment, or see symptom improvement early in PAP use are more likely to use their device appropriately.
Those with low self-efficacy or high treatment expectations are likely to be less adherent.
A multilevel approach that includes cognitive therapy, motivational interviewing, and telephone follow-up can improve adherence.
So can active patient involvement such as with myAir, an online support program and app that gives the patient a sleep score to track and motivates adherence.
Some patients benefit from pharmacotherapy, but studies have shown mixed results and side effects can be problematic.
“We need to individualize adherence approaches rather than use the same approach for everyone,” Dr. Pasha said.
The best adherence may not eliminate all symptoms. Up to 22% of patients with OSA who use PAP report symptoms of excessive daytime sleepiness (EDS).
“Every patient should be assessed for EDS,” said Meredith Greer, MD, Assistant Professor of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University. “Some may not recognize the problem because it is so familiar. Or they may not report sleepiness per se, more that they feel tired, fatigued, or not refreshed. EDS is significantly lower when patients use CPAP more than 6 hours per night, so we need to make sure it is working for them.”
Discussing lifestyle and sleep hygiene can help, she said, as can a medication review. Many commonly used medications can interfere with sleep, as can medical or psychological/neurological comorbidities.
Pharmacotherapy cannot replace CPAP, but modafinil, armodafinil, solriamfetol, and pitolisant may help reduce daytime sleepiness.
It is also important to ask about mask fit, especially for patients who have a high residual apnea-hypopnea (rAHI). The average AHI is 18.5, noted Ruckshanda Majid, MD, FCCP, Associate Professor and Co-Medical Director, Memorial Hermann Sleep Center, University of Texas McGovern Medical School, but every PAP machine has its own algorithm, resulting in a large degree of variation in reporting.
“If the data download shows a large rAHI, check the details,” Dr. Majid advised. “Not all devices are accurate. And always remember to look out for leaks. That needs to be addressed first.”
If there are no mask leaks, it is time to dig deeper, starting with the type of device.
A growing number of patients have auto-PAP machines rather than CPAP. These newer devices tend to be more accurate for low AHI, while high AHI counts tend to underreport actual event numbers.
Patient size is also a factor. Individuals with a high body mass index, greater than 30.9, are more likely to have underreported AHI counts.
“If you have a rAHI less than 10, your patient is probably doing well,” Dr. Majid said. “If the rAHI is over 20, check for leaks or pressure adjustments. The patient between 10 and 20 rAHI, you may need to bring back for a repeat polysomnogram, which will likely lead to a change in treatment.”
ACCESS SESSIONS ON DEMAND
Registered CHEST 2021 attendees have continued access to 200+ educational sessions until October 1, 2022. Watch sessions on your own schedule and earn up to 50 CME credits/MOC points.
Don’t forget to claim your credit! The deadline is December 15, 2022, at 11:59 pm CT.