OSA, CPAP Therapy and Residual Sleepiness Part II

Positional Therapy , Sleep Disorders , Case Studies , Snoring

OSA, CPAP Therapy and Residual Sleepiness Part II

In last week’s post, we presented that it is possible to still feel tired and sleepy after 6 hours of CPAP therapy. The condition is called CPAP resistant syndrome and it is actually experienced by about 10% of OSA patients that undergo CPAP therapy.

Residual sleepiness is one of the signs of CPAP resistant syndrome.  Two other causes of this syndrome are: unseen problems that affect CPAP therapy, and other conditions that are unrelated to CPAP therapy.

What are these unseen or hidden problems that decrease CPAP sleep quality?

  • Leaks -One of the most common causes of low quality of sleep when using a CPAP machine is a leaking mask. This is usually experienced by new and inexperienced CPAP users, thus most complain of headache, fatigue and daytime sleepiness even after a night of CPAP therapy. Even the minutest of leaks could affect one’s quality of sleep so it is best to fix it.


  • Air Pressure – Incorrect CPAP titration could happen with older CPAP machines. However, newer models are auto-adjusting which means air pressure during therapy will be adjusted based on the doctor’s prescribed air pressure range.
  • Mask Discomfort - It would naturally take some time for a person to adjust to sleeping with a CPAP mask sitting on his face. Though there is a range of CPAP masks based, adjusting to it takes time. Some of the more usual inconveniences due to CPAP mask usage are:
    • Feeling suffocated and claustrophobic
    • Constant sneezing of the user once the mask is worn
    • Dry mouth as a person undergoing CPAP therapy tends to open his mouth while sleeping
    • Nasal congestion in the morning
    • CPAP dry airflow during CPAP therapy

These discomforts must be addressed for an efficient and comfortable CPAP therapy. We will discuss pointers on how to remedy these problems on next week’s blog post.

What factors unrelated to CPAP could cause CPAP resistant syndrome, or low sleep quality?

CPAP therapy is the recommended treatment for obstructive sleep apnoea. However, it is not for central sleep apnoea, a form of sleep disorder wherein the brain lacks the efficiency to command the body to breathe.  In some cases, a person could have a combination of central and obstructive apnoea episodes. If this is the case diagnosing the disorder even after a sleep study could be very difficult. An unusual sleep pattern can be traced through one’s sleep data, and should only be interpreted by a qualified physician.   A bed partner can easily check if his/her partner still stops breathing in sleep even when using a CPAP machine.

There are medications that can make a person in CPAP therapy feel sleepy at daytime. These medications are sedatives and antidepressants. Since depression is a common co-morbidity of OSA, some patients under CPAP therapy take antidepressants. This group of drugs can affect one’s quality of sleep and therefore cause daytime sleepiness. Some of these medications are:

  • Anti-arrhythmics
  • Clonidine
  • Beta blockers
  • Corticosteroids
  • Medications containing alcohol
  • Diuretics
  • Sedating antihistamines
  • Selective serotonin reuptake inhibitors (SSRIs)
  • Theophylline
  • Medications containing caffeine
  • Thyroid hormone

It is best to consult with a doctor if you are taking any of these medications and undergoing CPAP therapy.

Next week, we will discuss on how to eliminate CPAP leaks and how to make a CPAP mask more comfortable to wear.


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