Many people suffer from sleep-related breathing disorders that prevent them from getting a good night’s rest. The most prevalent one is sleep apnea that is estimated to affect millions of people in the US alone. When you are not breathing correctly during the night, your body is not getting enough oxygen for its basic needs. Also, the carbon dioxide that is produced in the cell metabolism can’t be taken out, and its buildup can be toxic for your body. The first sign of many sleep-related breathing disorders is snoring. People also often experience daytime sleepiness, fatigue, impaired memory, concentration, and they have an increased risk of cardiovascular disease and diabetes type 2.
Good news is that adequate oxygen or positive air pressure (PAP) therapy are proven to be very effective with these conditions. They might not cure the disorders, but they significantly improve the symptoms, and people feel better rested after sleeping, and exhibit higher energy and oxygen blood levels during the day. Read on to learn more about the similarities and differences between continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) therapy.
What Conditions Can CPAP and BiPAP Treat?
Both CPAP and BiPAP are types of noninvasive ventilation therapy that are prescribed to help with symptoms of sleep apnea and other respiratory disorders that disturb sleep.
- Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by full or partial cessation of breath during sleep. Complete stoppage of inspiration is called apnea, while partial one is called hypopnea. These episodes can repeat many times each hour, and the severity of the condition is determined by the apnea-hypopnea index which describes the repetitiveness of these events per hour. The obstruction of the airway can be caused by excess fatty tissue in the throat, enlarged tongue or tonsils, and other conditions that might narrow the upper airway. Snoring is the most common symptom of OSA, while others include waking up in the middle of the night gasping for air, not feeling well rested in the morning, and daytime sleepiness and fatigue. OSA affects males more than females; huge risk factors are smoking, obesity, bigger neck size, and it also seems to affect the elderly more, probably due to the relaxation of muscles and tissues in their throats. OSA is the most prevalent of the following disorders.
- Central sleep apnea (CSA) is also characterized by apneas and hypopneas during the night, but unlike OSA, the problem is not an obstruction of the airway. In this disorder, the brain is not sending the proper signals to the muscles, and the results are irregular breathing patterns or too shallow inspirations. CSA is a lot less frequent than OSA, and it accounts for about 20% of all sleep apnea cases.
- Mixed or complex sleep apnea is described as a combination of both OSA and CSA. It is a rare condition, and it is often diagnosed after the initial CPAP treatment wasn’t successful. The individual would often first develop OSA, and then after not responding well to the CPAP therapy, some symptoms of CSA would appear leading to mixed sleep apnea.
- Congestive heart failure (CHF) is a chronic condition where the heart fails to pump enough blood to power the needs that rest of the body requires. There are many causes of this disorder, and since it is chronic and progressive, it requires lifelong treatment.
- Chronic obstructive pulmonary disorder (COPD) is a chronic lung disease where the inflammation causes obstructed airflow from the lungs. The most frequent causes for this condition are smoking, exposure to other pollutants and irritants such as fumes by burning fossil fuel for cooking, and improper home ventilation.
- Other pulmonary or neuromuscular disorders such as Parkinson’s disease or amyotrophic lateral sclerosis (ALS).
One thing that all of these conditions have in common is that people have a hard time to maintain proper breathing during sleep, which leads to disrupted blood flow and oxygen blood levels. If left untreated, these disorders can lead to a lot of sleep disturbances and many health conditions, that can drastically shorten a person’s lifespan. That is why adequate CPAP and BiPAP treatment is essential in improving symptoms in the affected population.
What Is CPAP?
Continuous positive airway pressure (CPAP) is usually the first treatment for OSA. It is widely successful in people with mild to moderate OSA symptoms. CPAP machine a steady, continuous flow of air, set at a defined pressure based on your needs. The device consists of a body that is the main powerhouse, and it is usually placed next to a patients bed. It works by sucking in the air from the room, which then goes through a specific filter to remove all the particles and impurities that may have a negative impact. The device then pressurizes the air to a certain degree that has been determined and set to suit an individual patient. Most of the machines also have a humidifier to prevent possible irritations such as the dry mouth and nasal cavity. The device usually comes with a setting that allows you to start at a lower than prescribed pressure, and then slowly increasing it to help you adjust to CPAP treatment. CPAP therapy requires some getting used to, and the person will usually adapt to it fully within the first few weeks.
The hose is carrying the pressurized air from the machine, and its diameters might vary, but the length is usually standard 6 feet. CPAP masks come in a variety of shapes and sizes to better suit the needs of every patient. However, there are three basic models: nasal masks, nasal pillow, and full face masks. First go over your nose, second rest comfortably in your nostrils, while the third one goes over your mouth and nose. Full face masks are a good option for people suffering from allergies, as their nose can often be congested, which prevents proper breathing and can also worsen symptoms of OSA.
CPAP devices use the constant flow of pressurized air, and that is one of the most common complaints among patients since many have a hard time breathing out with continuous flow. That is why newer CPAP models have a variable pressure setting such as AFLEX, C-FLEX, Bi FLEX, SenseAwake or EPR, depending on the manufacturer. This feature reduces pressure while exhaling, making it more comfortable to use. Some patients won’t ever need this setting, others will find it sufficient, while others might feel like CPAP is uncomfortable even with this feature. They might turn to an alternative of BiPAP, which is often prescribed if people have a hard time with CPAP treatment.
How is CPAP Pressure Determined?
The diagnosis of sleep apnea or other mentioned conditions is usually made in a sleep clinic where technicians do an overnight sleep study called polysomnography. After you have been diagnosed with a specific disease, the doctor will order a CPAP titration study to determine the appropriate pressure of your CPAP machine. This test might even be done on the same night that the polysomnography takes place.
First, a sleep technician fits a CPAP mask on your face, and you can decide between three standard designs. Full face masks are usually a good option for people with allergies. Nasal pillows are suitable for people with a lot of facial hair, or those who are somewhat uncomfortable with putting a mask over their face, while nasal ones are somewhere in the middle, being stable enough for people who toss and turn at night, but less bulky than the full face ones. After picking the right mask, you will go to sleep, and sleep technician will change the pressure during this time to find the best option for you.
What is APAP?
Auto-titrating positive airway pressure (APAP) functions similarly to CPAP. The difference is that the machine can sense subtle changes in breathing patterns, and automatically adjust a pressure setting according to a range from a titration study.
APAP is often prescribed to people who experience apneas during REM sleep, when they have allergies, or when they are sleeping on their backs. For example, when you are sleeping on your back, your tongue may fall back and obstruct the airway, which leads to longer and more frequent episodes. People with allergies may need a higher pressure to clear nasal congestion.
What Is BiPAP?
Bilevel positive airway pressure (BiPAP) is prescribed to people suffering from central sleep apnea, chronic obstructive pulmonary disorder, congestive heart failure, and other lung or neuromuscular disorders. It can also be prescribed for obstructive sleep apnea if CPAP therapy showed ineffective. That often happens in people with severe OSA, complex sleep apnea, or those who simply don’t respond well to CPAP therapy. For example, the most common complaint is that people find it hard to exhale with constant air pressure, and that is why BiPAP is a better option.
The way that BiPAP works is somewhat similar to CPAP. It delivers pressurized air to the user, but in this case, there are two distinct pressures, a higher one during the inhalation, and a lower one during exhalation. Most BiPAP devices also come with a feature that measures an optimal amount of breaths per minute. If you miss an inspiration in your sleep, the machine increases the air pressure and forces you to take a breath, therefore providing optimal airflow and oxygen blood levels.
Adaptive servo-ventilation (ASV) is an alternative option for those who don’t respond well to BiPAP therapy. These devices are more advanced and versatile as they can change the pressure, the volume, as well as the speed at which the air is being delivered, based on your needs.
CPAP And Bipap – Pros and Cons
Advantages of CPAP:
- It is the most cost-effective method of treating sleep apnea.
- Newer models have settings that allow lower pressure during expiration.
- It provides users with far better quality sleep, lessening the apnea events if used as prescribed.
- It prevents snoring.
- The use of CPAP lowers blood pressure, which prevents other heart-related issues from happening.
- Affected person’s sleeping partner also gets a better night’s rest due to fewer disruptions caused by snoring and apnea events.
- Lower stress levels, better mood, more energy and motivation during the day, and less daytime sleepiness.
Drawbacks of CPAP:
- The biggest one is getting used to CPAP treatment as some people may feel claustrophobic and uncomfortable upon exhaling. The result of this discomfort is infrequent use of a CPAP machine, which makes the treatment far less effective.
- The pressure setting is fixed.
- Wearing a mask can cause skin irritation, rashes, and itching.
- Some people may experience dry mouth.
- The fixed setting can become too weak or strong, depending on the changes in the user’s weight.
Advantages of BiPAP:
- It is very effective in treating people with severe sleep apnea and other health conditions.
- There are two different pressure settings, allowing users to exhale more comfortably against a lower pressure.
- The machine can force you to take a breath if you haven’t inspired in a certain period.
Drawbacks of BiPAP:
- It is more expensive than CPAP.
- You need to show insurance companies proof of prior use of a CPAP machine, to receive the approval for BiPAP.
- Eye irritation.
- Sinus problems.
- The development of complex sleep apnea in some cases where only OSA was present.
It is hard to determine which one is a better option. They both have strengths and drawbacks, but the good news is that both CPAP and BiPAP are highly effective in treating sleep-related breathing disorders. Keep in mind that BiPAP machines cost more to buy or rent and that the parts are also more expensive if something breaks down. The best way to decide which option is the best for you is to talk to your doctor. They can tell you more about your condition, and how to treat it, so stick with their prescription. If you don’t feel comfortable or notice that some other symptoms are developing, tell them right away, and help them figure out the best treatment for you.
Dusan is a biologist, a science enthusiast and a huge nature lover. He loves to keep up to date with all the new research and write accurate science-based articles. When he’s not writing or reading, you can find him in the kitchen, trying out new delicious recipes; out in the wild, enjoying the nature or sleeping in his bed.