Obstructive Sleep Apnea

Snoring is an involuntary sound generated from upper airway obstruction during sleep. Snoring can be due to obstruction from the nasal passages or oral passages. Up to 40% of individuals experience snoring, with some having associated serious medical conditions like obstructive sleep apnea.

Obstructive Sleep Apnea (OSA) is a condition whereby the body loses tone and partial control of the upper airway during the deeper stages of sleep, thereby causing obstruction.  

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 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 tighten the muscles in the area and taking a breath. As a result, this correction may manifest itself with a snorting or choking action.  

Most sufferers of obstructive sleep apnea (OSA) do not remember this event as the time they are awake is simply too short. However, in just an hour, 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! These interruptions therefore prevent or hamper the body’s ability to get to the deepest phases of sleep, where benefits of sleep are at its peak. This is why with poor quality sleep, patients can still feel tired despite sleeping for 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, sleep apnea tests were conducted in a sleep laboratory with one-night admission in the hospital, multiple leads attached to the forehead, face and chest of the patient. His/her quality of sleep would then be measured to determine if he/she was suffering from sleep apnea. However, such a method of testing did not prove to be fruitful as it led to the “first-night” effect, where patients were unable to fall asleep normally during the sleep test. 

It is important that patients can fall asleep normally during the sleep test itself as sleep apnea only occurs during sleep.

Otherwise, you may have to repeat the sleep test.

Another simpler way to do the sleep apnea test would be to use the WATCHPAT, an FDA-approved portable diagnostic device. With the WATCHPAT, sleep tests can be performed in the comfort of your own home or hotel. All that’s required is 4 hours of sleep time for accurate interpretation of the test results.

Picture of a patient with a WATCHPAT undergoing the sleep test

Depending on the severity of the condition, sleep apnea can lead to serious medical conditions as well as a poor quality of life.

Many people with obstructive sleep apnea (OSA) experience cardiovascular problems such as increased blood pressure risk having 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 during the sleep cycle.

Additionally, due to the poor quality of sleep experienced, sleep apnea sufferers often find themselves drowsy and fatigue during the day. They can also experience increased irritability and have difficulty concentrating on tasks. Some experience a higher risk of work-related accidents due to falling asleep during activities.

Lastly, relationships with partners may suffer when the patient’s loud snoring, sudden choking or coughing sounds disrupt and prevent those around them from getting good rest. A high percentage of partners of people who snore happen to be sleep deprived as well.

Yes, those on medication like sedatives, general anaesthetics and narcotic analgesics may find that their Obstructive Sleep Apnea (OSA) becomes worse. This is due to the additional relaxation of your upper airways, which leads to a compounded worsening of obstructive sleep apnea. 

I prescribe a Continuous Positive Airway Pressure (CPAP) 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 high pressure air straight into the patient’s nasal passages. This pump gets past blockages in the patient’s airway and allows for smoother breathing. Pressure that is delivered by the CPAP into the patient’s upper airway is supposed to be even and does not stop during the expiration cycle and the inspiration cycle of a patient’s breath.

The CPAP has been observed to be both an effective and a safe treatment for both children and adults. It has good benefits for cardiovascular health and aids in improving the sleepiness or lethargy felt during the day by patients.

If you are unable to use CPAP, it is important to find out the reason why. Sometimes, it could be a case of chronic rhinitis or nasal congestion, which makes it challenging for the machine to create the necessary air pressure. In this case, it is important to pre-treat the nose to relieve nasal congestion before doing CPAP therapy.

Otherwise, surgery is necessary to treat obstructive sleep apnea.

Before surgery, the surgeon will find areas of obstruction that cause obstructive sleep apnea. 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.