CPAP vs. BiPAP: What to Know
Some people with COPD, or COPD plus sleep apnea, may benefit from CPAP or BiPAP. So what are these, and how might they benefit you?
Ventilation. Your lungs make sure you are taking in enough oxygen and blowing off carbon dioxide. Oxygen is an essential element in the air that your cells need to make energy. Carbon dioxide (CO2) is a waste product made by cells. An inhalation of an adequate depth is required for adequate ventilation to occur.
Diseases like COPD and Sleep Apnea may compromise ventilation, making it so you are not taking in enough oxygen and/ or blowing off enough CO2.
COPD. The disease process increases resistance in your airways, forcing you to work hard to take in a breath. This causes shallow breathing, causing areas inside your lungs that do not stay patent, a medical term for open. Less ventilation occurs, causing your oxygen levels to fall and your CO2 levels to rise.
Sleep Apnea. Soft upper airway tissue may collapse while you are sleeping, causing you to stop breathing for ten seconds to a minute. You may have up to 30 such episodes during a typical night. During these episodes you are not inhaling oxygen, causing your oxygen levels to drop. You are also not blowing off CO2, causing your CO2 levels to rise. This can make daytime living difficult, and may even increase your risk of dying while you are sleeping.
So, what are CPAP and BiPAP, and how might they help**?** They are non-invasive machines that supply a pressure to keep your airway patent and to assist you with your breathing.
CPAP. This is an acronym for Continuous Positive Airway Pressure. A continuous flow of pressure is applied during inspiration and expiration. It keeps your alveoli patent to assure adequate oxygenation. It keeps your upper airway patent to prevent apnea.
BiPAP. This is an acronym for Bi-Level Positive Airway Pressure. It provides a combination of IPAP and EPAP.
IPAP. This is Inspiratory Positive Airway Pressure. It is a pressure during inspiration that assists your inhalation (makes it easier to inhale). It makes sure you are ventilating, or taking a deep enough breath to blow off CO2. It also makes breathing easier by allowing you to rest your respiratory muscles.
EPAP. This is Expiratory Positive Airway Pressure. It is the same thing as CPAP, only it’s called EPAP when used with a BiPAP machine. It simply makes sure your airways stay patent so the next breath comes easier.
Sleep study. This is necessary to determine if you need CPAP or BiPAP. You will be hooked up to a variety of monitors, and a sleep technician will monitor you while you are sleeping. If you have apnea episodes, or if your oxygen levels drop, the technician will determine what pressures are ideal for you.
Home. Your doctor may determine you need CPAP or BiPAP at home. These are set up by home health care providers for you to wear every night. They fit nicely on a nightstand, and are usually very quiet and comfortable.
Hospital. When you are having a COPD flare-up, a doctor may prescribe CPAP or BiPAP to help you breathe better. These are used short term to buy time for other therapies ordered by your doctor to start working, such as bronchodilators, corticosteroids, antibiotics, and diuretics.
These are usually set up and managed by a respiratory therapist like myself.
Masks. There are a whole assortment of nasal pillows, nasal masks, face masks, and full face masks for you to try. Your home health provider will help you find which one that works best for you.
Compliance. Most people find that the benefits of using these machines – such as improved quality of life – make them very easy to get used to. Of course it helps that modern machines and masks are made with your comfort in mind. So if your physician recommends you try CPAP or BiPAP, please give it a try. You may find that it greatly improves your quality of life.
John Bottrell is a registered Respiratory Therapist. He wrote for HealthCentral as a health professional for Asthma and Chronic Obstructive Pulmonary Disease (COPD).