Central sleep apnea less common than obstructive apnea

DEAR DR. ROACH » I am a 94-year-old man who was diagnosed with central sleep apnea about six years ago by my pulmonologist. Try as I may, I have been unable to adjust to an assortment of apnea masks that are connected to a BiPAP machine (which is attached to oxygen). I have threatened to give it up, but I have been warned by my doctors of the risk of stroke, heart problems and more. The only symptom I experience when I don’t use the mask is drowsiness. I’d like your opinion of my shedding the mask and machine, and getting by just with oxygen. — S.M.L.

DEAR READER » Obstructive sleep apnea is a common enough condition that most people know it: The muscles of the airway relax during sleep, and in some people, especially those who are overweight or just have the neck anatomy to permit it, the airway can become completely closed. It is treated with a continuous positive airway pressure (CPAP) mask, which uses pressure to keep the airway open. The mask needs to fit very tightly on the face. It is uncomfortable, but most people eventually get accustomed to it. Alternatives to CPAP include BiPAP, which has two different settings of airway pressure (for inspiration and exhalation), and ASV (adaptive servoventilation), which varies the amount of pressure to the amount of respiratory effort. All of these options require masks.

By contrast, central sleep apnea is much less common or well-known. In most cases of central sleep apnea, the problem starts in the brain, with excess breathing. Low oxygen level is one root cause of this. The person responds by breathing rapidly, which drives the carbon dioxide level down, which then causes a period of no breathing at all (apnea).

Treatment for central sleep apnea may use any of these breathing masks. My experience has been that it may take months to find a well-fitting mask, and a good respiratory therapist is an invaluable friend in finding this. However, if you can’t get a good result with a mask, then you can consider oxygen alone. It may be that supplemental oxygen prevents the initial low oxygen level that triggers the rapid breathing. You need to speak with your pulmonologist, but if you have the usual kind of fast-breathing-triggered CSA, oxygen may be a reasonable treatment.

Oxygen alone (without CPAP) is potentially dangerous for people with obstructive sleep apnea.

DEAR DR. ROACH » My son is 51 years of age, and apparently in good health. He had chickenpox as a young child. My concern is whether he should get the shingles vaccination now, or wait until he is older. I have heard that the vaccine wears off as you get older, and I wonder if he should wait until he is older and hope he does not get the shingles earlier. — L.C.

DEAR READER » I recommend waiting until 60. The shingles vaccine becomes more important as people get older, partially because the vaccine wears off, but mostly because shingles is worse in older people. In particular, the likelihood of getting severe post-herpetic neuralgia, the pain syndrome that can follow shingles, is higher, and when it does, it lasts longer in older people. That’s why expert groups recommend getting the vaccine at age 60. A new vaccine in development hopefully will be longer-lasting and more effective.

Contact Dr. Roach at ToYourGoodHealth@med. cornell.edu.