Question: What is (are) Obesity Hypoventilation Syndrome ?
Answer: Obesity hypoventilation (HI-po-ven-tih-LA-shun) syndrome (OHS) is a breathing disorder that affects some obese people. In OHS, poor breathing results in too much carbon dioxide (hypoventilation) and too little oxygen in the blood (hypoxemia). OHS sometimes is called Pickwickian syndrome. Overview To understand OHS, it helps to understand how the lungs work. When you breathe, air passes through your nose and mouth into your windpipe. The air then travels to your lungs' air sacs. These sacs are called alveoli (al-VEE-uhl-eye). Small blood vessels called capillaries (KAP-ih-lare-ees) run through the walls of the air sacs. When air reaches the air sacs, oxygen passes through the air sac walls into the blood in the capillaries. At the same time, carbon dioxide moves from the capillaries into the air sacs. This process is called gas exchange. In people who have OHS, poor breathing prevents proper gas exchange. As a result, the level of carbon dioxide in the blood rises. Also, the level of oxygen in the blood drops. These changes can lead to serious health problems, such as leg edema (e-DE-mah), pulmonary hypertension (PULL-mun-ary HI-per-TEN-shun), cor pulmonale (pul-meh-NAL-e), and secondary erythrocytosis (eh-RITH-ro-si-TOE-sis). If left untreated, OHS can even be fatal. The cause of OHS isn't fully known. Researchers think that several factors may work together to cause the disorder. Many people who have OHS also have obstructive sleep apnea. Obstructive sleep apnea is a common disorder in which the airway collapses or is blocked during sleep. This causes pauses in breathing or shallow breaths while you sleep. Obstructive sleep apnea disrupts your sleep and causes you to feel very tired during the day. (For more information, go to the Health Topics Sleep Apnea article.) Outlook Doctors treat OHS in a number of ways. One way is with positive airway pressure (PAP) machines, which are used during sleep. PAP therapy uses mild air pressure to keep your airways open. Your doctor might recommend CPAP (continuous positive airway pressure) or BiPAP (bilevel positive airway pressure). If your doctor prescribes PAP therapy, you'll work with someone from a home equipment provider to select a CPAP or BiPAP machine. The home equipment provider will help you select a machine based on your prescription and the features that meet your needs. Other treatments for OHS include ventilator (VEN-til-a-tor) support and medicines. (A ventilator is a machine that supports breathing.) OHS occurs with obesity, so your doctor will likely recommend weight loss as part of your treatment plan. Successful weight loss often involves setting goals and making lifestyle changes, such as following a healthy diet and being physically active. OHS can lead to other serious health problems, so following your treatment plan is important. Your health care team, home equipment provider, and family can help you manage your treatment.
Source: NHLBI

Question: What causes Obesity Hypoventilation Syndrome ?
Answer: Obesity hypoventilation syndrome (OHS) is a breathing disorder that affects some obese people. Why these people develop OHS isn't fully known. Researchers think that several factors may work together to cause OHS. These factors include: A respiratory (RES-pih-rah-tor-e) system that has to work harder than normal and perhaps differently because of excess body weight. (The respiratory system is a group of organs and tissues, including the lungs, that helps you breathe.) A slow response by the body to fix the problem of too much carbon dioxide and too little oxygen in the blood. The presence of sleep apnea, usually obstructive sleep apnea.
Source: NHLBI

Question: How to diagnose Obesity Hypoventilation Syndrome ?
Answer: Obesity hypoventilation syndrome (OHS) is diagnosed based on your medical history, signs and symptoms, and test results. Specialists Involved A critical care specialist, pulmonologist (lung specialist), and/or sleep specialist may diagnose and treat your condition. A sleep specialist is a doctor who diagnoses and treats sleep problems. Examples of such doctors include lung and nerve specialists and ear, nose, and throat specialists. Other types of doctors also can be sleep specialists. Your health care team also may include: A registered dietitian or nutritionist to help you plan and follow a healthy diet. (Your primary care doctor also might oversee weight-loss treatment and progress.) An exercise physiologist or trainer to assess your fitness level and help create a physical activity plan that's safe for you. A bariatric surgeon if weight-loss surgery is an option for you. Medical History and Physical Exam Your doctor will ask about your signs and symptoms, such as loud snoring or daytime sleepiness. He or she also may ask about your use of alcohol and certain medicines, such as sedatives and narcotics. These substances can worsen OHS. During the physical exam, your doctor will listen to your heart with a stethoscope. He or she also will check to see whether another disease or condition could be the cause of your poor breathing. Diagnostic Tests In OHS, poor breathing leads to too much carbon dioxide and too little oxygen in the blood. An arterial blood gas test can measure the levels of these gases in your blood. For this test, a blood sample is taken from an artery, usually in your wrist. The sample is then sent to a laboratory, where the oxygen and carbon dioxide levels are measured. Other tests also can measure the carbon dioxide level or oxygen level in your blood. These tests include a serum bicarbonate test and pulse oximetry. A serum bicarbonate test measures the amount of carbon dioxide in the liquid part of your blood, called the serum. For this test, a blood sample is taken from a vein, usually in your wrist or hand. Pulse oximetry measures the level of oxygen in your blood. For this test, a small sensor is attached to your finger or ear. The sensor uses light to estimate how much oxygen is in your blood. Other Tests Your doctor may recommend other tests to help check for conditions and problems related to OHS. Polysomnogram A polysomnogram (PSG) is a type of sleep study. You usually have to stay overnight at a sleep center for a PSG. The test records brain activity, eye movements, heart rate, and blood pressure. A PSG also records the amount of oxygen in your blood, how much air is moving through your nose while you breathe, snoring, and chest movements. The chest movements show whether you're making an effort to breathe. Your doctor might use the PSG results to help diagnose sleep-related breathing disorders, such as sleep apnea. Lung Function Tests Lung function tests, also called pulmonary function tests, measure how well your lungs work. For example, these tests show: How much air you can take into your lungs. This amount is compared with that of other people your age, height, and sex. This allows your doctor to see whether you're in the normal range. How much air you can blow out of your lungs and how fast you can do it. How well your lungs deliver oxygen to your blood. The strength of your breathing muscles. Chest X Ray A chest x ray is a test that creates pictures of the structures inside your chest, such as your heart, lungs, and blood vessels. This test can help rule out other conditions that might be causing your signs and symptoms. EKG (Electrocardiogram) An EKG is a test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through your heart. The results from an EKG might show whether OHS has affected your heart function. Other Tests A complete blood count (CBC) can show whether your body is making too many red blood cells as a result of OHS. A CBC measures many parts of your blood, including red blood cells. A toxicology screen is a group of tests that shows which medicines and drugs you've taken and how much of them you've taken. A blood or urine sample usually is collected for a toxicology screen.
Source: NHLBI

Question: What are the treatments for Obesity Hypoventilation Syndrome ?
Answer: Treatments for obesity hypoventilation syndrome (OHS) include breathing support, weight loss, and medicines. The goals of treating OHS may include: Supporting and aiding your breathing Achieving major weight loss Treating underlying and related conditions Breathing Support Positive Airway Pressure Treatment for OHS often involves a machine that provides positive airway pressure (PAP) while you sleep. PAP therapy uses mild air pressure to keep your airways open. This treatment can help your body better maintain the carbon dioxide and oxygen levels in your blood. PAP therapy also can help relieve daytime sleepiness. Your doctor might recommend CPAP (continuous positive airway pressure) or BiPAP (bilevel positive airway pressure). CPAP provides continuous mild air pressure to keep your airways open. BiPAP works almost the same, but it changes the air pressure while you breathe in and out. The machines have three main parts: A mask or other device that fits over your nose or your nose and mouth. Straps keep the mask in place while you're wearing it. A tube that connects the mask to the machine's motor. A motor that blows air into the tube. Some machines have other features, such as heated humidifiers. The machines are small, lightweight, and fairly quiet. The noise they make is soft and rhythmic. Some people who have OHS receive extra oxygen as part of their PAP treatment. However, oxygen therapy alone isn't recommended as a treatment for OHS. PAP therapy also is used to treat obstructive sleep apnea. Many people who have OHS also have this common condition. If your doctor prescribes PAP therapy, you'll work with someone from a home equipment provider to select a CPAP or BiPAP machine. The home equipment provider will help you pick a machine based on your prescription and the features that meet your needs. Ventilator Support If you have severe OHS that requires treatment in a hospital, you might be put on a ventilator. A ventilator is a machine that supports breathing. This machine: Gets oxygen into your lungs Removes carbon dioxide from your body Helps you breathe easier A ventilator blows air, or air with extra oxygen, into the airways through a breathing tube. One end of the tube is inserted into your windpipe, and the other end is hooked to the ventilator. Usually, the breathing tube is put into your nose or mouth and then moved down into your throat. A tube placed like this is called an endotracheal (en-do-TRA-ke-al) tube. Endotracheal tubes are used only in a hospital setting. Sometimes the breathing tube is placed through a surgically made hole called a tracheostomy (TRA-ke-OS-toe-me). The hole goes through the front of your neck and into your windpipe. The procedure to make a tracheostomy usually is done in an operating room. You'll be given medicine so you won't feel any pain. The tracheostomy allows you to be on a ventilator in the hospital, in a long-term care facility, or at home. Talk with your doctor about how long you'll need ventilator support and whether you can receive treatment at home. For more information about ventilator support, go to the Health Topics Ventilator/Ventilator Support article. Weight Loss Your doctor will likely recommend weight loss as part of your treatment plan. Successful weight loss often involves setting goals and making lifestyle changes. For example, eating fewer calories and being physically active can help you lose weight. Medicines and weight-loss surgery might be an option if lifestyle changes aren't enough. Your doctor will advise you on the best weight-loss treatment for you. For more information about weight loss, go to the treatment section of the Health Topics Overweight and Obesity article. Medicines Your doctor may prescribe medicines to treat OHS (although this treatment is less common than others). Your doctor also may advise you to avoid certain substances and medicines that can worsen OHS. Examples include alcohol, sedatives, and narcotics. They can interfere with how well your body is able to maintain normal carbon dioxide and oxygen levels. If you're having surgery, make sure you tell your surgeon and health care team that you have OHS. Some medicines routinely used for surgery can worsen your condition.
Source: NHLBI

Question: How to prevent Obesity Hypoventilation Syndrome ?
Answer: You can prevent obesity hypoventilation syndrome (OHS) by maintaining a healthy weight. However, not everyone who is obese develops OHS. Researchers don't fully know why only some people who are obese develop the condition. Adopting healthy habits can help you maintain a healthy weight. Many lifestyle habits begin during childhood. So, it's important to make following a healthy lifestyle a family goal. A healthy diet is an important part of a healthy lifestyle. A healthy diet includes a variety of vegetables and fruits. It also includes whole grains, fat-free or low-fat dairy products, and protein foods, such as lean meats, eggs, poultry without skin, seafood, nuts, seeds, beans, and peas. A healthy diet is low in sodium (salt), added sugars, solid fats, and refined grains. Solid fats are saturated fat and trans fatty acids. Refined grains come from processing whole grains, which results in a loss of nutrients (such as dietary fiber). Examples of refined grains include white rice and white bread. For more information about following a healthy diet, go to the National Heart, Lung, and Blood Institute's "Your Guide to Lowering Your Blood Pressure With DASH" and the U.S. Department of Agriculture's ChooseMyPlate.gov Web site. Both resources provide general information about healthy eating. To adopt other healthy lifestyle habits, follow these tips: Focus on portion size. Watch the portion sizes in fast food and other restaurants. The portions served often are enough for two or three people. Children's portion sizes should be smaller than those for adults. Cutting back on portion sizes will help you manage your calorie intake. Be physically active. Make personal and family time as active as possible. Find activities that everyone will enjoy. For example, go for a brisk walk, bike or rollerblade, or train together for a walk or run. Reduce screen time. Limit the use of TVs, computers, DVDs, and videogames; they cut back on the time for physical activity. Health experts recommend2 hours or less a day of screen time that's not work- or homework-related. Keep track of your weight and body mass index (BMI). BMI is calculated from your height and weight. In adults, a BMI of 30 or more is considered obese. You can use the NHLBI's online BMI calculator to figure out your BMI, or your doctor can help you. For more information, go to the prevention section of the Health Topics Overweight and Obesity article. Even if you have OHS, you might be able to prevent the condition from worsening. For example, avoid alcohol, sedatives, and narcotics. These substances can interfere with how well your body is able to maintain normal carbon dioxide and oxygen levels.
Source: NHLBI