What is Apnea?
Sleep apnea is a breathing disorder characterized by brief interruptions of breathing during sleep that affects men and women of all ages. It owes its name to a Greek word, apnea, meaning "want of breath". There are two types of apneas, the more common obstructive sleep apnea (OSA) and the less common central sleep apnea (CSA).
Obstructive Sleep Apnea
According to the Canadian Lung Association, obstructive sleep apnea occurs when upper airway gets blocked during sleep. Most often, the blockage happens when the soft tissue in the back of the throat becomes markedly reduced (hypopnea) or collapses and closes during sleep (apnea). The body realizes that it is no longer breathing and you wake up to take a breath. This pattern happens repeatedly throughout the night (sometimes 50 to 100 times per hour) and it severely disrupts your sleep. Very often you wake up in the morning to find that you are tired.
Central Sleep Apnea
Central sleep apnea is much rarer syndrome than OSA. It occurs when the brain fails to send the appropriate signals to the breathing muscles to initiate respirations. So, rather than an obstruction in the throat, it is the brain that is causing central sleep apnea. It is often the result of neurologic damage (stroke) or cardiovascular complications, such as congestive heart failure (CHF).
Who is at risk?
Patients suffering from the following conditions may be at risk for OSA:
- Habitual snoring
- High blood pressure
- Family history of OSA or snoring
- Small upper airway (large tongue, recessed chin, excess tissue in the throat and/or soft palate)
Factors which may make snoring and apnea worse on a given night:
- Sleeping on the back
- Alcohol at bedtime
- Sleeping pills or narcotic (sedating) pain pills at bedtime
The prevalence of OSA in North America is estimated to be between 5 and 10% of the population. Most of those at risk are not screened for OSA and go undiagnosed. Most people with OSA don't know they are snoring or waking up at night and gasping for air. Also, they have become accustomed to daytime sleepiness. For these reasons, they do not speak with their family physicians about the symptoms. Very often it is the bed partner who reports these signs and prompts the sufferer to seek help. OSA can be a serious problem that is easy to detect and treat.
Signs and SymptomsFirst thing in the morning:
- Dry mouth
- Unrestored feeling
- Morning headache
- Lack of energy
- Irritability and moodiness
- Fatigue and sleepiness
- Lack of sex drive
- Difficulty with focus, memory
- Getting up frequently to go to the bathroom
- Occasional choking sensation
- Snoring and snorting awake witnessed by others
- Restless sleep
- Night sweating
- Increased collar size (>17.5" in men, >15.5" around in women)
- High blood pressure requiring several medications for control and readings higher in the morning than in the afternoon
- Swelling of the feet or ankles
How can I be diagnosed?
If you think you have sleep apnea, you can speak with your family doctor, who may refer you for a sleep study. Obstructive sleep apnea can be easily diagnosed with a Home Sleep Test.
How is my apnea measured?
There are varying degrees of sleep apnea and they are measured according to the number of times one stops breathing (apnea) or has a reduction in breathing (hypopnea) per hour of sleep. This is known as one’s AHI index (Apnea-Hypopnea Index)
AHI of 5 - 15 - Mild OSA
AHI of 15 - 30 - Moderate OSA
AHI over 30 - Severe OSA
For example. if your AHI is over 50, it means that you stop breathing every minute and wake up to breathe and drift off to sleep again. You never get the restorative sleep that is required to function normally during the day. Moreover, your body is working all night, stressing your heart.
How is OSA Treated?
The most commonly prescribed treatment for OSA is Continuous Positive Airway Pressure (CPAP). There are other alternative treatments, such as, oral devices and surgery. These options are generally prescribed for mild snoring and mild cases of sleep apnea. Non-specific measures in the control of mild sleep apnea include learning to sleep off supine (see positional therapy at http://www.css.to/brochures.html) and avoiding alcohol or sedation and weight control. You can discuss these options with your physician.
How does CPAP work?
Continuous Positive Airway Pressure, as the name suggests, delivers a flow of pressurized air to keep your airway open. The pressure is delivered through a 2 m tube to a mask which fits over your nose or in your nares. The purpose of the pressure is to act as a splint to keep your throat open.
Blocked Airway Airway "splinted" open
The component parts of CPAP include:
- Small bedside device called a flow generator that delivers the pressurized air
- Integrated humidifier (attached to device) to add moisture to the air before you breathe
- 2m tube connected to the flow generator
- Mask worn by patient to which tube is connected CPAP must be prescribed by a physician and in Quebec only a registered respiratory therapist can administer the treatment.
Types of CPAP
Our respiratory therapists will help you to choose the mask that best fits you and that will make your treatment effective. Mask fitting is everything. Like a pair of shoes, if it fits properly and it is comfortable, wearing a mask will be easier. This is where our experienced personnel can help you.
There are various types of CPAP. Depending on your doctor's prescription and your individual needs, you will require either one of three of the following devices:
CPAP (Continuous Positive Airway Pressure) delivers a constant pressure and this pressure is determined by the sleep doctor. This is the minimum pressure necessary to eliminate obstructive breathing. It is often called "fixed" CPAP because the pressure is set to one constant.
APAP (Automatic Positive Airway Pressure) delivers a pressure that continually adjusts breath by breath to give you the lowest pressure needed to keep the airway open and prevent obstructed breathing. It is also known as auto-adjusting CPAP therapy. This is designed for patients with varying needs because of medications, alcohol, allergies or a changing sleep position. This type of device can also be programmed to work in a fixed CPAP pressure if the prescription needs to be changed. A small number of patients do not tolerate APAP. Often, this is because they sense the change in pressure and this wakes them up.
Bilevel CPAP devices deliver two set pressures: one for when you breathe in (inspiratory pressure) and a second pressure for when you breathe out (expiratory pressure). This type of treatment is used for people who do not tolerate CPAP therapy or who require ventilatory assistance (eg. COPD sufferers).
Types of Mask
There are 3 types of masks to suit the patient's individual needs. It is very important that the mask is comfortable and provides a proper seal for the airflow; the proper air pressure level cannot be established unless the fit is correct. A comfortable mask that fits well will make using CPAP easier.
1. The nasal mask covers the patient nose. It is the most commonly used mask.
2. Nasal pillows provide direct nasal delivery and a clear field of vision. This mask is generally recommended for those who feel claustrophobic when sleeping with a nasal mask or full face mask.
3. A full face mask is the best solution for those patients who breathe through their mouth.
What are the benefits of CPAP therapy?
- Improved quality of life
- Increased energy levels
- Improved job performance
- Increased intellectual functioning/ concentration and memory
- Less anxiety and depression
- Alertness while driving
- Reduction in EDS (Excessive Daytime Sleepiness)
- Lower blood pressure
- Lower blood sugar levels in patients with type 2 diabetes
- Less stress on your heart and cardiovascular system
- Reduce likelihood of stroke
What are the possible consequences of untreated OSA?
- Excessive daytime sleepiness (EDS)
- High blood pressure
- Heart disease
- Car accidents (OSA patients are 6 times more likely to have a car accident, Santos, Spain)
- Work-related accidents
- Poor quality of life
- Decreased intellectual functioning
- Type 2 diabetes
- Sexual dysfunction