Sleep Apnea for Dummies
BY Rafael Mendonca, RRT Manager
Mar 3, 2022
From start to finish: The Complete Guide on Sleep Apnea
What is sleep apnea?
By straight definition sleep apnea refers to the cessation of breathing for over 10 seconds. With newer studies however, sleep apnea has come to be much more complex than we once thought. Lets dig in on what it is as well as what we do about it...
Categories of Sleep Apnea
Sleep apnea can be categorized in 3 main sections: Obstructive Sleep Apnea, Central Sleep Apnea and Complex Sleep Apnea. Furthermore there are other types of sleep disorders such as Hypopnea, Obesity-Hypoventilation Syndrome (OHS), Cheyne-Stokes-Respirations (CSR), Respiratory Effort Related Arousal (RERA), and Upper Airway Resistance Syndrome. I don't mean to throw too much jargon here, but my point is there is much more to this illness than meets the eye and treatment of sleep apnea should be equally as important as any other illness such as hypertension and diabetes. For the purposes of this write up, we will be focusing on the first 3.
Obstructive Sleep Apnea (OSA)
OSA is The most prevalent type of sleep apnea that affect majority of the population suffering from sleep apnea. Obstructive Apnea is defined as a complete blockage of the upper airway by the tongue falling in the back of the mouth pushing against the soft palate and back of the throat. With a blocked airway while asleep, we will not know it happened or for how long it happened. During this time, the individual will try to keep breathing but is unsuccessful in getting any air in until there is a gasp for air. This gasp for air is the body's sympathetic response (fight or flight) to open the mouth for increased air intake due to the stress of lower oxygenation & higher carbon dioxide levels in the blood. The interruption in peaceful rest will cause the brain waves to skip the deep stages of sleep, the most restorative stages of sleep and ironically where we are more prone to obstructions to take place thus resulting in an overall lighter, non-restorative state of sleep.
Hypopneas often go hand in hand with obstructive sleep apnea. Hypopnea is now (as of 2017) defined as a 30% reduction in airflow that is associated with an oxygen desaturation event. With Hypopneas, there is always airflow going in and out of the lungs. However the quantity of air is significantly reduced and therefore affects the gas exchange inside the lungs. Carbon Dioxide won't be able to be exhaled as it should and the supply of fresh oxygen in the distal parts of the lungs called the alveoli will not be able to provide the body with sufficient oxygen. Although it is partial obstructions, it is still considered sleep apnea due to the fact it is associated with oxygen desaturations. This causes the sympathetic response to kick in and kicks the individual out of deep stages of sleep such as Stage 3 & REM.
Central Sleep Apnea (CSA)
As you can see from the picture on the left, Central Sleep Apnea (CSA) may be one of the more complex types of sleep disordered breathing there is. In fact, up today there are only theories with strong backing evidence based research as to why it happens but there are no groundbreaking discoveries as of yet. So what is it? CSA is the cessation in breathing for over 10 seconds where there is an open airway but no drive to breathe. Truth is CSA is present even in the healthiest of individuals. Everyone has it to some degree even if it is extremely minor. It also may occur for several reasons such as untreated chronic sleep apnea, post-stroke, post-heart attack, neurologic degenerative diseases and more. If CSA is present to a degree affecting sleep quality, there may an underlying issue. At the end of the day, therapy for CSA is a fixed pressure only includes CPAP without EPR/A-FLEX or a BiPAP ST for CSA that do not go away with a fixed pressure of CPAP with no EPR/A-FLEX. If there are other medical issues associated with the CSA, BiPAP ST-A/ AVAPS or BiPAP ASV may be recommended.
Complex Sleep Apnea
Sometimes referred to as "Mixed Sleep Apnea" is referring to nocturnal apneic events where there is a mixture of Central, Obstructive and Hypopneas. Generally speaking, central sleep apnea will be accompanied by another form of apnea. When these are found together further investigation may be needed as there is a greater chance of more significant sleep disordered breathing such as Cheyne-Stokes-Respirations which is related to Cardiac health.
How Do I get it assessed?
In Canada, the assessment process differs by province. For example, British Columbia and Alberta both accept either a Level 1 (Sleep Lab Testing) or Level 3 (Home Sleep Apnea Testing) sleep testing for a full diagnosis and treatment coverage through extended health care. This makes it convenient for anyone to request a timely sleep test, have the option of sleeping in your own environment to get a more precise test based on routine. So in a nutshell, the differences are listed below:
Level 3 testing is limited to 5 sensors: air flow, oxygenation, heart rate, breathing efforts, positional sensor. This test covers the main components needed for true diagnosis of sleep apnea. Like with any good invention and technology there is always a downside. The flaws are mainly that the testing does not have real-time support so patient errors are the leading cause of repeat testing needed as well as being unable to see who performed the test as no one is there to witness.
A level 1 test covers everything the level 3 test does plus EEG, ECG, periodic leg movement sensors, eye movement, jaw clenching/grinding of teeth, abdominal paradoxical breathing and a video camera that views the patient all night. Clearly the Level 1 test is the superior test theoretically speaking, however when it comes to practicality and accessibility to the general public, there is a bottle neck effect that hinders proper timely treatment of those affected by this illness.
Provinces such as Ontario, Manitoba and Saskatchewan all have provincially-regulated-CPAP funding which means there are much more strict criteria that has not been changed or updated with new studies since the 1980s (Refer to the NCBI Study) . Having said that, Level 3 at-home tests are available in Ontario however the Ministry does not recognize it for funding of the medical equipment. Due to no government support for the Level 3 testing, it would cost approximately $350.00 CAD for a one-night test which includes a one-on-one appointment with a sleep therapist and an interpretation from the Polysomnography Technologist/RRT and physician. Although the cost can be a bit high, it can prevent months upon months of delay. It also serves as a starting point to see if further studies are needed in the sleep lab for funding of medical equipment.
Sleep Apnea Treatment
Ultimately treatment of Sleep Apnea or sleep breathing disorders will fall under the category of CPAP or BiPAP which are the golden standard of sleep apnea treatment. To view some CPAP and BiPAP Machines
In the unlikely event where CPAP or BiPAP therapy is not tolerated, an Oral Appliance Therapy (OAT) may be prescribed. Please do keep in mind that OATs do NOT treat anything other than mild, Moderate and at times severe obstructive sleep apnea. There are One-Size fits all at drugstores and the very expensive custom made by the dentist that specializes in sleep medicine. Whatever you do, please do not cheap out on this therapy. Teeth are constantly moving and through experience the one-size-fits-all seems to do more harm than good with many people regretting paying the $200.00 vs. a $2000.00 fix.
FAQ & Common misconceptions
But I don't wake up gasping so I don't have sleep apnea.
Think again! Just because someone may not wake up gasping from the apneic episode, it is a far cry from not having it and may be used as a deterrent to not get tested. Reality is that 80% or more of people with sleep apnea do not wake up in a panic like one would think. Rather, usually there is a peaceful wakening throughout the night and the individual will either have a bathroom break with a full bladder (due to cardiac stress brought upon by lack of breathing, low oxygen and higher blood pressure due to physiological stress) and/or have insomnia due to the sympathetic system kicking in (fight or flight).
I move so much and have all my life even as a child! A CPAP machine won't work for me.
In the past decade I cannot begin to say how many times I have heard this and how many times I have had to explain that is the wrong thought process. Remember, sleep apnea does NOT come out of nowhere. It has been likely there for a very, very long time (yes even children have it) and if you had sleep issues as a child, look no further unless we are trying to keep it a mystery that no doctor can solve. It is very common for children to have an undiagnosed sleep disorder because who would think to have it tested? Technology advances every year as does medical research. The research is there, the general public's mindset is not but it will catch up one day.
In Conclusion, YES CPAP absolutely may help your restlessness. By providing a deeper uninterrupted sleep and being able to achieve a normal sleep architecture, the restless will subside as a result.
My partner doesn't do well with loud sounds. Will the CPAP be an issue?
I'll start by asking, do you snore? If so, even a humming CPAP will be quieter.
To answer this question in full, CPAP machines have come a long way. They used to be loud, have mechanical sounds and humming like a generator. However, that is far from waht they are today. In fact, throughout my career I have noticed an increasing amount of younger population starting to get their sleep checked. Is it a coincidence? Do more people have sleep apnea than before? Or is it because of increased availability of testing and more vigorous tools to assess sleep deprivation? Food-for-thought.
I'm not overweight therefore I don't have sleep apnea.
Far from the truth and is one of the main misconceptions and reasons why many sleep apnea sufferers go undiagnosed until other health conditions start to take place. Literature used to indicate to screen obese patients for sleep apnea as they are prone to airway collapse due to extra tissues around the neck and shallow breathing due to excess weight on the diaphragm and chest wall. However through research weight is found to only be one aspect that affects severity of sleep apnea. Other factors to consider are Age, Sex, Smoking history, Occupation and anatomical build (hereditary). Furthermore, if OSA was purely a weight issue, why do people that go through massive weight loss (100 lbs or more) still get diagnosed with sleep apnea pre and post weight loss? The likeliness sleep apnea will reduce to normal levels where you will feel symptomatically better is very, very low. When people come to me and ask if it is a permanent therapy, the answer is always "likely, yes."
Everyone wakes up at night for bathroom breaks, its just a process of getting older!
Try again! Yes, that is right. This is my FAVOURITE mindset that I absolutely love educating and proving (through lots and lots of denial and reluctance) to my patients until they realize I am not a sales person, rather a respiratory therapist looking out for their health and spreading the latest facts about the disease. It is NOT normal to have increased bathroom breaks regardless of friends and family members doing the same. Imagine saying that about headaches and irritability associated to high blood pressure (hypertension) before the late 1800s when they were finally discovered a method to measure blood pressure? Check this link to find out more on the discovery of blood pressure.
So how does sleep apnea affect bathroom breaks? When our bodies go through physiological stress due to collapsed or partially collapsed airways we go through a sympathetic response where nor-epinephrine (Adrenaline) is released, a few physiological responses start to happen.
First, there is diversion of blood flow from non-vital organs to vital organs as a survival response to increase oxygen uptake by the more important organs (brain and heart).
Second, adrenaline is a beta agonist which means it increases heart rate for faster output of blood and increases blood pressure for faster and more efficient delivery to vital organs.
Third, in normal circumstances the pituitary glands in the base of the brain naturally releases a hormone called the Anti-Diuretic Hormone (ADH). When this is released, it is meant to divert blood flow from the kidneys preventing the production of urine allowing humans to sleep for longer periods without the need of urination. In a physiological state of stress such as sleep apneic events, this process is overridden because the body's natural response to hypertension is to eliminate fluid. Therefore the kidneys primary purpose will to reduce the volume of blood/fluid in our arteries to lower the blood pressure naturally. They will work in overdrive to produce more urine by filtrating the blood.
Fourth, Did you know the sympathetic response also causes glucose to be released? Having elevated amounts of sugar can cause to increased urination (pre-diabetic stages) and insulin deficiency leading to onset of Diabetes Mellites. If we stop and think about it, if you get tested for glucose levels int he morning shortly after waking up, not having eaten anything in the past 8-10 hours, how can glucose levels be high if we really did have a "good sleep". Good sleep is subjective and if there is no optimal sleep to compare it to, the sleep experienced may always be "good" because we don't know otherwise.
Will I die if I leave sleep apnea untreated?
Never have I ever told anyone that they would likely die in their sleep if they didn't get treatment rather focused on comorbidities going forward and overall quality of life. However if the oxygen levels are severely low and there is history of cardiac disease and other comorbidities, then it could absolutely be a possibility.