A Complete Overview of Central Sleep Apnea
As a sleep technologist, your ability to identify sleep disorders such as central sleep apnea is essential in order to enable the physician to determine a correct diagnosis and prescribe the appropriate therapy.
What is Central Sleep Apnea (CSA)?
Central sleep apnea is a condition where your patient's breathing effort stops during sleep. Central sleep apnea, or CSA for short, results when your patient's brain isn't sending the right signals to their muscles that control their breathing. CSA differs from obstructive sleep apnea (OSA), which occurs when the airway collapses and obstructs the upper airway. With CSA, which is less common than OSA, there is no effort to breathe even though the airway is open.
Medical conditions, such as stroke and heart failure, may lead to central sleep apnea. It can also occur due to sleeping at a high altitude. CSA treatment may include your patient using a PAP device that helps them breathe, or supplemental oxygen.
Discover key terms that every sleep technologist should know in our free eBook.
Central sleep apnea in adults is made up of five primary categories. These include:
- Primary Central Sleep Apnea: The breathing pattern with primary central sleep apnea consists of the repeated absence of airflow and breathing effort. There's no known cause.
- Cheyne-Stokes Breathing Pattern: The Cheyne-Stokes breathing pattern consists of rhythmic waxing and waning of breathing effort (increasing and decreasing) and air flow. Common causes include stroke and heart failure.
- Medical Condition Not Cheyne-Stokes: Medical conditions can also cause CSA that does not show the Cheyne-Stokes breathing pattern. Kidney and heart problems are common causes. Another cause may be an injury to the base of the brain where your patient's breathing is controlled.
- High-Altitude Periodic Breathing: Sleeping above 15,000 feet altitudes may cause a periodic breathing pattern that is similar to the Cheyne-Stokes breathing pattern, but with a shorter cycle time, and without a history of any medical issues such as stroke, kidney failure, or heart failure.
- Due to Drug or Substance: Drug use can cause CSA, particularly opioid pain medications. Your patient's breathing may be shallow or repeatedly stop completely when taking these medications. Some drugs may also cause irregular breathing, as well as combined CSA and OSA.
What Are the Symptoms of Central Sleep Apnea?
Common central sleep apnea signs and symptoms include:
- Shortness of breath with abrupt awakenings
- Observed abnormal breathing or stopped breathing patterns while sleeping
- Insomnia (difficulty staying asleep)
- Shortness of breath that gets better while sitting up
- Difficulty concentrating
- Nighttime chest pain
- Morning headaches
- Hypersomnia (excessive daytime sleepiness)
- Mood changes
Snoring is not a component of CSA, but may be present in patients who have a combination of CSA and OSA.
If your patient is experiencing symptoms or signs of CSA, they should contact their doctor and visit you for a sleep study. This is particularly true if they're experiencing CSA symptoms such as:
- Recurrent pauses in their breathing while they're sleeping
- Shortness of breath that wakes them up while sleeping
- Excessive daytime drowsiness that causes them to fall asleep while driving, working, or watching TV
- Insomnia or trouble staying asleep
You should inquire about any sleep issues that leave them chronically sleepy, fatigued, and irritable. Other disorders may be causing their hypersomnia such as OSA or narcolepsy.
Risk Factors of Causes of Central Sleep Apnea
Your patients may have certain factors that increase their risk of CSA such as:
- Age. CSA is more common in adults over the age 65, likely because they might have medical conditions that are causing their CSA.
- Sex. CSA is more common in males than females.
- Brain tumor, stroke, or a structural brainstem lesion. Conditions of the brain like these can impair your patient's brain's ability to regulate their breathing.
- Heart disorders. Patients with congestive heart failure or atrial fibrillation have a higher risk of getting CSA.
- High-altitude. When your patient sleeps at a higher altitude than they are used to, it could increase their risk of central sleep apnea or periodic breathing pattern. However, once they return to a lower altitude, this is no longer a problem.
- CPAP. Some patients with OSA who use CPAP (continuous positive airway pressure) develop complex sleep apnea, or induced CSA. This often resolves after a period of time on CPAP.
- Opioid use. As mentioned above, patients who are taking opioid medications have a high risk of CSA.
How is Central Sleep Apnea Diagnosed?
Your patient's doctor will take their medical history, perform a physical exam, and take a sleep history. After that, they'll likely refer them to you, the sleep technologist, to perform a polysomnogram (an overnight sleep study).
During the polysomnogram, you will monitor body functions, including their:
- Brain electrical activity
- Eye movements
- Heart rate
- Muscle activity
- Breathing effort
- Blood oxygen levels
You may perform a full-night sleep study, or in some cases a split-night sleep study. With a split-night study, you monitor your patient during the first part of their night, then initiate continuous positive airway pressure (CPAP) for the rest of the night if OSA is evident. A split night study is not generally appropriate in patients diagnosed with CSA.
During polysomnography, you can rule out other types of sleep disorders, such as periodic limb movements, OSA, or narcolepsy. All of these sleep disorders can cause excessive daytime sleepiness bue each require a different treatment than central sleep apnea does.
Additionally, other health care professionals like neurologists and cardiologists may be involved in the evaluation of these patients due to their contributing disorders.
Treatment Options for Central Sleep Apnea
There are several treatment options for central sleep apnea. These are:
CPAP stands for continuous positive airway pressure. It is a type of sleep apnea therapy that delivers air pressure to the patient’s airway using a nasal mask that your patient wears on their face while they sleep.
CPAP is set at a predetermined setting in a continuous stream of air that maintains an open airway while the patient sleeps.
CPAP therapy helps your patient tremendously by:
- Keeping their airway open while they sleep.
- Eliminating or at least reducing their snoring.
- Improving their sleep quality.
- Eliminating or reducing their daytime sleepiness.
As soon as your patients begin treatment, they should start feeling the effects. Many patients show maximum improvement within a couple of days or weeks after starting therapy.
Adaptive Servo-Ventilation (ASV)
Adaptive servo-ventilation, or ASV, may be indicated for a patient if CPAP isn't effective. ASV is a non-invasive treatment used to treat adults with OSA and CSA or complex sleep apnea. ASV is a newer type of PAP device that monitors your patient's breathing issues continuously and adjusts as needed to maintain breathing. ASV adjusts based on the patient's breathing efforts, meaning the pressure delivered isn't a value that's fixed, but instead adapts to the breathing patterns of your patient.
If the ASV device detects any breathing abnormalities, it will intervene with enough support to keep your patient's breathing at least 90 percent of their baseline breathing pattern. With this continuing adjustment, when your patient has stable breathing, the device offers the right pressure support to reduce work of breathing and thereby increase patient comfort.
Bilevel Positive Airway Pressure (BiPAP) is similar to CPAP therapy.
A common complaint of the CPAP device is that the constant pressure is uncomfortable for them to breathe against when they exhale; which can be a challenge if they're using CPAP at higher pressures.
However, with using BiPAP, your patients can easily breathe, since the device decreases the pressure level during exhalation. This allows your patient to more comfortably on PAP therapy. BiPAP machines come with two pressure settings: a lower exhalation pressure and a higher pressure during inhalation. These are known as IPAP and EPAP or inspiratory and expiratory PAP settings.
Your patient's BiPAP device increases their pressure while they're inhaling to ensure their airway is kept from closing while they're sleeping. It also provides a lower exhalation pressure that continually maintains an open airway. Patients using BiPAP typically find it more comfortable than using a CPAP device with a single pressure.
Other treatments for central sleep apnea may include treating relevant medical problems, decreasing opioid medication, providing medicine that stimulates breathing, using supplemental oxygen and treating underlying conditions that cause CSA.
- With CSA, your patient's breathing effort stops, or starts and stops, repeatedly while they sleep.
- Stroke and heart failure can trigger CSA.
- There are risk factors that increase your risk of CSA including age, sex, and certain health conditions.
- There are several treatment options for CSA including CPAP, BiPAP and ASV.
For more information on Central Sleep Apnea, and to obtain a must-read reference guide for sleep technologists who are looking to advance their knowledge, click here to download our ebook, Sleep Technology Terms & Definitions.