Obstructive Sleep Apnea

Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disorder characterized by repetitive episodes of nocturnal breathing cessation due to upper airway collapse. Obstructive Sleep Apnea (OSA) causes severe symptoms, such as excessive daytime somnolence, and is associated with significant cardiovascular morbidity and mortality.

Snoring is a sound generated from upper airway obstruction during sleep. The production of this snoring sound is involuntary and can be due to obstruction from the nasal passages or oral passages. Up to 40% of individuals experience snoring. Some of these patients who experience snoring may have associated serious medical conditions like obstructive sleep apnea.

Obstructive Sleep Apnea (OSA) is a condition whereby there is obstruction in the upper airway during sleep. As the body loses tone and partial control of the upper airway especially during the deeper stages of sleep.


This can happen when the muscles located in the throat loosen and relax when asleep, causing several parts along your breathing passage like the soft palate (the soft tissue at the roof of the back of your mouth), the uvula (the hanging, triangular structure hanging from the soft palate), the tongue and tonsils to narrow or be close completely — causing obstructions to breathing, leading to snoring or a stop in breathing. This impairment in breathing may lead to lowering of oxygen levels in your body and rising carbon dioxide levels. 


As the amount of oxygen in your blood drops and the levels of carbon dioxide begin to buildup, the brain detects this change as inadequate breathing and sends a signal to disrupt your sleep momentarily. During this time the patient may not be fully awake, thus these are known as micro-awakenings. This interruption in sleep allows your body to correct the breathing obstructions and open your airway again by tightening the muscles in the area and taking a breath. This correction may also manifest itself with a snorting or choking action.  

Most sufferers of obstructive sleep apnea (OSA) do not remember this event as the time you are awake is simply too short. However, this cycle of relaxing of airway muscles, having your breathing impaired, then getting briefly awoken by your brain to resume proper breathing can happen up to 30 times or more in an hour, for the entire duration of sleep! These interruptions prevent or hamper the body’s ability to get to the deepest phases of sleep where the benefits of sleep are the highest for you. With a poor quality of sleep, the patients can feel sleepy and tired, even after sleeping for a full 8 hours.

The patient may also experience the following symptoms of sleep apnea:

  • Snoring
  • Choking during sleep
  • Daytime somnolence
  • Falling asleep easily in the day
  • Compensating fatigue with coffee intake

Associated medical conditions of sleep apnea includes:

  • Hypertension / High blood pressure
  • Cardiac disease / arrhythmias / Heart failure
  • Diabetes
  • Fatty liver
  • Increased chance of road traffic accidents
  • Headaches
  • Depression
  • Stroke
  • Sudden death

Obstructive Sleep Apnea (OSA) occurs from obstruction of breathing in the airways during sleep. This can be from either the nasal passages, oral passages or both. 

1. Nasal Passages

  • Deviated nasal septum
  • Inferior turbinate hypertrophy
  • Adenoid hypertrophy (usually in kids)

2. Oral Passages

  • Tonsils
  • Large tongue
  • Large soft palate

Sleep Apnea is usually diagnosed with a sleep test. In the past, we used to perform sleep apnea tests in a sleep laboratory with one-night admission in the hospital. The patient will have multiple leads attached to the forehead, face and chest area. His/her quality of sleep would then be measured to determine if he/she was suffering from sleep apnea. This however led to the one problem known as the “first-night” effect. This happens when the patient is unable to fall asleep normally during the sleep test. 

Sleep apnea only occurs only during sleeping. There will be no obstructions in the airway whilst the patient is awake. So it is important that you can fall asleep normally during the sleep test itself.

Otherwise, you may have to repeat the sleep test.

Another simpler way to do the sleep apnea test would be to use the WATCHPAT. This can even be performed in the comfort of your own home or hotel and all we need is 4 hours of sleep time for accurate interpretation of the test results.

Picture of a patient with a WATCHPAT undergoing the sleep test

Picture of a patient with a WATCHPAT undergoing the sleep test

Depending on the severity of the condition, if you have moderate or severe sleep apnea, it can lead to serious medical conditions that may arise as a result.

Due to the poor quality of sleep experienced, patients and sufferers of sleep apnea find themselves afflicted with daytime drowsiness and fatigue easily. They can also experience increased irritability and have difficulty concentrating on tasks. Serious cases involve a higher risk of falling asleep during activities, such as at work or while driving, leading to an increased risk in work-related accidents.

Many people with obstructive sleep apnea (OSA) also experience cardiovascular problems such as increased blood pressure and run an increased risk of heart failure, heart attack and stroke as a result.  This is due to the extra strain on the cardiovascular system caused by the repeated, sudden drops in blood oxygen levels due to obstructive sleep apnea (OSA).  

Relationships with partners may suffer when the patient’s loud snoring or sudden choking or coughing sounds disrupt and prevent those around them from getting good rest. It is no surprise that a high percentage of partners of people who snore happen to be sleep deprived as well.

Medications may worsen obstructive sleep apnea as well. Your upper airways may be additionally relaxed by medications such as sedatives, general anaesthetics and narcotic analgesics and leading to a compounded worsening of obstructive sleep apnea. 

What is a Continuous Positive Airway Pressure (CPAP): Continuous Positive Airway Pressure is a treatment that I prescribe to tackle regular as well as more severe cases of obstructive sleep apnea.

The CPAP is a sort of face mask that is worn by patients whilst sleeping. The CPAP machine is linked up to a pump mechanism, that pumps air staright into your nasal passages. The air being pumped is at a high pressure, which will manage to get past any blockages in your airway and allow the patient to breathe at a more normal pace. Pressure that is delivered by the CPAP into the patient’s upper airway is supposed to be even and does not stop during either the expiration cycle and the inspiration cycle of a patient’s breath.

Continuous Positive Airway Pressure has been observe to be both an effective and a safe treatment, for both children and adults. This will have an effect on improving the sleepiness or lethargy felt during the day.  It also has good benefits for your cardiovascular health as well as an overall improvement of quality of life for the patient.

CPAP (Continuous positive airway pressure)

If you are unable to use CPAP, it is important to find out the reason before surgery. Sometimes chronic rhinitis or nasal congestion can make it challenging for the machine to create the necessary air pressure CPAP treatment requires to be helpful. In this case, it is important to pre-treat the nose to relieve the nasal congestion before doing CPAP therapy.

If a patient is really unable to use CPAP, surgery is an option that can help treat this condition.

Surgery is targeted at treating the areas of obstruction. For example, if a patient has large tonsils, tonsillectomy can help treat this condition. If there are nasal causes of obstruction, a septoplasty or turbinate reduction surgery can help treat the sleep apnea too. The type of surgery performed will be tailored to the individual patient and his site of obstruction so it can be variable. Thankfully with the latest technologies, surgeries can now be performed in a minimally invasive manner in a relatively painless manner.

Click here for Dr Dennis Chua article published in Business Times 2016 on Tackling Obstructing

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