How Oxygen Cylinder Works?

Medical Oxygen Cylinder

An oxygen tank is a storage vessel for oxygen, which is either held under pressure in gas cylinders or as liquid oxygen in a cryogenic storage tank. Oxygen tanks are used to store gas for medical breathing gas at medical facilities and at  home

Breathing oxygen is delivered from the storage tank to the users by use of the following methods: oxygen masknasal cannulafull face diving maskoxygen tent, and hyperbaric oxygen chamber.


Contrary to popular belief scuba divers very rarely carry oxygen tanks. The vast majority of divers breathe air or nitrox stored in a diving cylinder. A small minority breathe trimixheliox or other exotic gases. Some of these may carry pure oxygen for accelerated decompression or as a component of a rebreather. Some shallow divers, particularly naval divers, use oxygen rebreathers or have done so historically.


Oxygen is rarely held at pressures higher than 200 bar / 3000 psi due to the risks of fire triggered by high temperatures caused by adiabatic heating when the gas changes pressure when moving from one vessel to another.


All equipment coming into contact with high pressure oxygen must be “oxygen clean” and “oxygen compatible” to reduce the risk of fire. “Oxygen clean” means the removal of any substance that could act as a source of ignition. “Oxygen compatible” means that internal components must not burn readily or degrade easily in a high pressure oxygen environment.


In some countries there are legal and insurance requirements and restrictions on the use, storage and transport of pure oxygen. Oxygen tanks are normally stored in well ventilated locations, far from potential sources of fire and concentrations of people.

How Oxygen Concentrator Works?

How does oxygen concentrator work?

The main component in the air

  • Nitrogen – 78%
  • Oxygen – 21%
  • Other – 1%

How to change the percentage in the air we breathe by using Oxygen Concentrator?

Normal air contains only 21% oxygen we need to either add or remove something from the air to improve the ability of the patient’s lungs to function. The easiest way is to remove the largest element from the mix. If we remove all of the nitrogen we are left with oxygen and small amounts of other elements (primarily argon, an inert gas).

With nitrogen gone (78% of the air we started with) the percentage of oxygen (which was 21%) and ‘other’ (which was 1%) now become:

  • Oxygen – 95%
  • ‘Other’ – 5%

What this is ultimately stating is that the maximum oxygen concentration we can get by removing nitrogen from the air is around 95%. This is important to note when comparing products. None can give more than this percentage but an inefficient design can surely give less.

Oxygen Therapy for Patients

While the above elements work well for people with normal lung functioning, patients with COPD need a stronger concentration of oxygen when they inhale. There are several ways to accomplish this goal:

  • Oxygen Generators (concentrators)
  • High pressure oxygen tanks

The source of pure oxygen rely on a regular, steady supply to be delivered to the patient’s home.

Only oxygen concentrators have the capability to create the proper amount of oxygen without outside services.


How Nitrogen is removed from the air

Methods were found that reliably separate specific gas elements. One of these has been adopted for most oxygen concentration systems. PSA (Pressure Swing Adsorption) causes this separation to occur using pressure, as the name implies. Pressure alone doesn’t perform the magic. A special material was also developed to do the hard work. This material is called Zeolite and is actually a microscopic cube with holes on all six sides. Nitrogen molecules chemically bond to its surfaces as they pass through; letting only Oxygen and ‘Other’ elements flow through unimpeded.

The Zeolite is housed in air tight cylinders called ‘sieve beds’. Most oxygen concentrators use two of these ‘beds’ (more on that later). Of course, once the Zeolite has adsorbed its maximum load of Nitrogen molecules it can’t stop the rest of the Nitrogen from passing through.


Oxygen Concentrator

Major Components:


Component Function
Inlet Air Filter Stops larger particles from entering the system
Compressor Pulls in air and pressurizes it to enable the Zeolite to work better
Sieve Beds Contain the Zeolite which removes Nitrogen from the air forced into it
Product (oxygen) Tank Collects the final product (95% pure oxygen) for delivery to the patient
Switching Valves Control the routing of the air through the sieve beds and product tank

The operation of the entire machine is controlled by a microprocessor. The only (normally) operator settable characteristic is output flow (settings of 1 through 5 ).

Most units include some visual and audible alarms (low oxygen, battery failure, etc.)


PSA Process


The following is a simplistic explanation of the Pressure Swing Adsorption process used in oxygen concentrators:

  1. Room air is pulled in through the inlet filter by the inlet side of the compressor.
  2. The air is compressed and forced into sieve bed A (‘charge’ cycle)
  3. Oxygen is forced through the sieve bed into the Product Tank
  4. After several seconds sieve bed A becomes saturated (full) of Nitrogen
  5. The switching valves reroute the gas flow:
  1. Compressed air is now forced into Sieve Bed B
  2. Sieve Bed A inlet (compressor) side is ‘ported’ to atmosphere (the room)
  3. A small amount of pure (95%) oxygen from the product tank flows backward into Sieve Bed A
    1.                                                          i.            The combination of pressure drop in Sieve Bed A (we just opened it to atmosphere) and the backflow of pure oxygen cause the Zewolite to release the captured Nitrogen molecules. The Oxygen and Nitrogen remix and enter the room as ‘normal’ air.

The air is compressed and forced into sieve bed B (‘charge’ cycle)

Oxygen is forced through the sieve bed into the Product Tank

After several seconds the cycle repeats with Sieve Bed A

What is COPD?

What is COPD?

Chronic obstructive pulmonary disease (COPD),is the occurrence of chronic bronchitis or emphysema, a pair of commonly co-existing diseases of the lungs in which the airways become narrowed. This leads to a limitation of the flow of air to and from the lungs, causing shortness of breath (dyspnea). In clinical practice, COPD is defined by its characteristically low airflow on lung function tests. In contrast to asthma, this limitation is poorly reversible and usually gets progressively worse over time. In England, an estimated 842,100 of 50 million people have a diagnosis of COPD.


COPD is caused by noxious particles or gas, most commonly from tobacco smoking, which triggers an abnormal inflammatory response in the lung. The diagnosis of COPD requires lung function tests. Important management strategies are smoking cessationvaccinationsrehabilitation, and drug therapy (often using inhalers). Some patients go on to require long-term oxygen therapy or lung transplantation.


Worldwide, COPD ranked as the sixth leading cause of death in 1990. It is projected to be the fourth leading cause of death worldwide by 2030 due to an increase in smoking rates and demographic changes in many countries.[5] COPD is the third leading cause of death in the U.S. and the economic burden of COPD in the U.S. in 2007 was $42.6 billion in health care costs and lost productivity.


What is Chronic bronchitis?

Lung damage and inflammation in the large airways results in chronic bronchitis. Chronic bronchitis is defined in clinical terms as a cough with sputum production on most days for 3 months of a year, for 2 consecutive years. In the airways of the lung, the hallmark of chronic bronchitis is an increased number (hyperplasia) and increased size (hypertrophy) of the goblet cells and mucous glands of the airway. As a result, there is more mucus than usual in the airways, contributing to narrowing of the airways and causing a cough with sputum. 


Inflammation is followed by scarring and remodeling that thickens the walls and also results in narrowing of the airways. As chronic bronchitis progresses, there is squamous metaplasia (an abnormal change in the tissue lining the inside of the airway) and fibrosis (further thickening and scarring of the airway wall). The consequence of these changes is a limitation of airflow.


What is Emphysema?

Lung damage and inflammation of the air sacs (alveoli) will result in emphysema. Emphysema is defined as enlargement of the air spaces distal to the terminal bronchioles, with destruction of their walls. The destruction of air space walls reduces the surface area available for the exchange of oxygen and carbon dioxide during breathing. It also reduces the elasticity of the lung itself, which results in a loss of support for the airways that are embedded in the lung. These airways are more likely to collapse causing further limitation to airflow.


Signs and symptoms

One of the most common symptoms of COPD is shortness of breath (dyspnea). People with COPD commonly describe this as: “My breathing requires effort,” “I feel out of breath,” or “I can’t get enough air in”. People with COPD typically first notice dyspnea during vigorous exercise when the demands on the lungs are greatest. Over the years, dyspnea tends to get gradually worse so that it can occur during milder, everyday activities such as housework. In the advanced stages of COPD, dyspnea can become so bad that it occurs during rest and is constantly present.


Other symptoms of COPD are a persistent cough, sputum or mucus production, wheezing, chest tightness, and tiredness.[17][18]

People with advanced (very severe) COPD sometimes develop respiratory failure. When this happens, cyanosis, a bluish discoloration of the lips caused by a lack of oxygen in the blood, can occur. An excess of carbon dioxide in the blood can cause headaches, drowsiness or twitching (asterixis). A complication of advanced COPD is cor pulmonale, a strain on the heart due to the extra work required by the heart to pump blood through the affected lungs.


There are a few signs of COPD that a healthcare worker may detect although they can be seen in other diseases. Some people have COPD and have none of these signs. Common signs are:

  • tachypnea, a rapid breathing rate
  • wheezing sounds or crackles in the lungs heard through a stethoscope
  • breathing out taking a longer time than breathing in
  • enlargement of the chest, particularly the front-to-back distance (hyperaeration)
  • active use of muscles in the neck to help with breathing
  • breathing through pursed lips
  • increased anteroposterior to lateral ratio of the chest (i.e. barrel chest).




The primary risk factor for COPD is chronic tobacco smoking. In the United States, 80 to 90% of cases of COPD are due to smoking. Exposure to cigarette smoke is measured in pack-years, the average number of packages of cigarettes smoked daily multiplied by the number of years of smoking. The likelihood of developing COPD increases with age and cumulative smoke exposure, and almost all life-long smokers will develop COPD, provided that smoking-related, extrapulmonary diseases (cardiovascular, diabetes, cancer) do not claim their lives beforehand.


Air pollution:

Studies in many countries have found people who live in large cities have a higher rate of COPD compared to people who live in rural areas. Urban air pollution may be a contributing factor for COPD, as it is thought to slow the normal growth of the lungs, although the long-term research needed to confirm the link has not been done. Studies of the industrial waste gas and COPD/asthma-aggravating compound, sulfur dioxide, and the inverse relation to the presence of the blue lichen Xanthoria (usually found abundantly in the countryside, but never in towns or cities) have been seen to suggest combustive industrial processes do not aid COPD sufferers.



There is currently no cure for COPD; however, COPD is both a preventable and treatable disease. Clinical practice guidelines for the management of COPD are available from the Global Initiative for Chronic Obstructive Lung Disease (GOLD), a collaboration that includes the World Health Organization and the U.S. National Heart, Lung, and Blood Institute. The major current directions of COPD management are to assess and monitor the disease, reduce the risk factors, manage stable COPD, prevent and treat acute exacerbations and manage comorbidity.

The only measures that have been shown to reduce mortality is smoking cessation and supplemental oxygen.


Supplemental oxygen:

Supplemental oxygen can be given to people with COPD who have low oxygen levels in the body. Oxygen is provided from an oxygen cylinder or an oxygen concentrator and delivered to a person through tubing via a nasal cannula or oxygen mask. Supplemental oxygen does not greatly improve shortness of breath but can allow people with COPD and low oxygen levels to do more exercise and household activity. Long-term oxygen therapy for at least 16 hours a day can improve the quality of life and survival for people with COPD and arterialhypoxemia or with complications of hypoxemia such as pulmonary hypertensioncor pulmonale, or secondaryerythrocytosis.[56] High concentrations of supplemental oxygen can lead to the accumulation of carbon dioxide and respiratory acidosis for some people with severe COPD; lower oxygen flow rates are generally safer for these individuals. Another safety issue concerning the use of oxygen for patients with COPD is smoking, because the combination of smoking and oxygen can result in fire accidents. Nowadays oxygen is generally only given to patients who have stopped smoking.


Other measures

Pulmonary rehabilitation is a program of exercise, disease management and counselling coordinated to benefit the individual. Pulmonary rehabilitation has been shown to improve shortness of breath and exercise capacity. It has also been shown to improve the sense of control a patient has over their disease as well as their emotions.

Being either underweight or overweight can affect the symptoms, degree of disability and prognosis of COPD. People with COPD who are underweight can improve their breathing muscle strength by increasing their calorie intake. When combined with regular exercise or a pulmonary rehabilitation programme, this can lead to improvements in COPD symptoms.

Surgery is sometimes helpful for COPD in selected cases. A bullectomy is the surgical removal of a bulla, a large air-filled space that can squash the surrounding, more normal lung. Lung volume reduction surgery is similar; parts of the lung that are particularly damaged by emphysema are removed allowing the remaining, relatively good lung to expand and work better. Lung transplantation is sometimes performed for severe COPD, particularly in younger individuals.

Patients should be given annual influenza vaccinations and pneumococcal vaccinations if appropriate. Obesity, poor nutrition, depression and social isolation are looked at. Palliative care for end of life needs is important. Morphine and benzodiazepines are used in low doses to reduce anxiety. In advanced critical illness, decisions about resuscitation are addressed.


Lung cancer

Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary lung cancers, are carcinomas that derive from epithelial cells. The main types of lung cancer are small cell lung carcinoma (SCLC), also called oat cell cancer, and non-small cell lung carcinoma (NSCLC). The most common cause of lung cancer is long-term exposure to tobacco smoke. Nonsmokers account for 15% of lung cancer cases, and these cases are often attributed to a combination of genetic factors, radon gas, asbestos, and air pollution including secondhand smoke.


The most common symptoms are coughing (including coughing up blood), weight loss and shortness of breath. Lung cancer may be seen on chest radiograph and computed tomography (CT scan). The diagnosis is confirmed with a biopsy. This is usually performed by bronchoscopy or CT-guided biopsy. Treatment and prognosis depend on the histological type of cancer, the stage (degree of spread), and the patient’s general wellbeing, measured by performance status. Common treatments include surgery, chemotherapy, and radiotherapy. NSCLC is sometimes treated with surgery, whereas SCLC usually responds better to chemotherapy and radiation therapy. This is partly because SCLC often spreads quite early, and these treatments are generally better at getting to cancer cells that have spread to other parts of the body.


Survival depends on stage, overall health, and other factors, but overall 15% of people in the United States diagnosed with lung cancer survive five years after the diagnosis. Worldwide, lung cancer is the most common cause of cancer-related death in men and women, and is responsible for 1.3 million deaths annually, as of 2004.


Signs and symptoms


If the cancer grows in the airway, it may obstruct airflow, causing breathing difficulties. The obstruction can lead to accumulation of secretions behind the blockage, and predispose to pneumonia. Many lung cancers have a rich blood supply. The surface of the cancer may be fragile, leading to bleeding from the cancer into the airway. This blood may subsequently be coughed up.


Many of the symptoms of lung cancer (bone pain, fever, and weight loss) are nonspecific; in the elderly, these may be attributed to comorbid illness. In many patients, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Common sites of metastasis include the brain, bone, adrenal glands, contralateral (opposite) lung, liver, pericardium, and kidneys. About 10% of people with lung cancer do not have symptoms at diagnosis; these cancers are incidentally found on routine chest radiograph.



Heart Failure


How It Works:

Oxygen therapy is a way to get more oxygen into your lungs and bloodstream. It is sometimes used for people who have diseases that make it hard to breathe, such as heart failure. Oxygen therapy can make it easier to breathe. And it can reduce the heart’s workload.


Some people need extra oxygen all the time. Others need it from time to time throughout the day or overnight. A doctor will prescribe how much oxygen you need, based on blood tests. He or she will tell you how much oxygen to use per minute (the flow rate) and how often to use it.


To breathe the oxygen, most people use a nasal cannula (say “KAN-yuh-luh”). This is a thin tube with two prongs that fit just inside your nose. Children and people who need a lot of oxygen may need to use a mask that fits over the nose and mouth.

You don’t have to stay at home or in a hospital to use oxygen. Oxygen systems are portable. You can use them while you do your daily tasks.


Why It Is Used:

Your doctor will determine how much oxygen you need with a blood test called arterial blood gas and another test called oximetry. These tests measure the levels of oxygen in the blood.

Long-term oxygen therapy is given to people with heart failure who have low levels of oxygen in their blood. It is given to increase the amount of oxygen in the blood to provide for the body’s needs.

Oxygen therapy can decrease shortness of breath and allow you to do more.


How Well It Works:

Oxygen therapy helps reduce the heart’s workload. In heart failure, the heart does not pump as effectively as it should and does not meet the body’s needs for oxygen. Oxygen therapy helps compensate by increasing the amount of oxygen delivered to the body’s tissues. Home oxygen therapy can help decrease shortness of breath and increase your capacity to exercise.


Side Effects:

In general, there are no adverse effects from oxygen treatment. But oxygen is a fire hazard. It is important to follow safety measures to keep you and your family safe. Do not use oxygen around lit cigarettes, open flames, or flammable substances.

Your doctor will set the flow rate per minute to give you the right amount of oxygen. Don’t change the flow rate unless your doctor tells you. Higher flow rates usually do not help and can increase the risk of harmful carbon dioxide buildup in the blood, especially in those people who also have lung disease.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)


What To Think About:

Do not use oxygen around lit cigarettes, open flames, or flammable products. If you or those who care for you smoke, be sure to consider oxygen therapy very carefully because of the danger of fire or explosion.

How Portable Oxygen Works?

Portable oxygen concentrator

Portable oxygen concentrator (or POC) is a portable device used to provide oxygen therapy to a patient at substantially higher concentrations than the levels of ambient air. It is very similar to a home oxygen concentrator, but is smaller in size and more mobile. The portable oxygen concentrator makes it easy for patients to travel freely; they are small enough to fit in a car and most of the major concentrators are now FAA-approved.



Portable oxygen concentrators have been around for decades; but the older versions were bulky, not reliable, and were not permitted on airplanes. Since 2000, a number of manufactures have improved their reliability and they now produce anywhere between 1 and 6 liters per minute (LPM) of oxygen. There are versions that provide pulse or continuous flow. The portable concentrators plug directly into a regular house outlet for charging at home or hotel; but they came with a power adapter that can usually be plugged into a vehicle DC adapter. They have the ability to operate from the battery power as well for either ambulatory use, or away from a power source, or on an airplane.


How does it work?

The technology behind a Portable Oxygen Concentrator is based on the same principle as a home domestic concentrator. Air at barometric pressure contains 21% oxygen combined with nitrogen and a mixture of other gases. A miniaturised compressor inside the machine will pressurise this air through a system of chemical filters known as a molecular sieve. This chemical filter is made up of silicate granules called Zeolite. The Zeolite will sieve the nitrogen out of the air, concentrating the oxygen. Part of the produced oxygen is delivered to the patient; part is fed back into the sieves to clear the system of the accumulated nitrogen, making it ready for the next cycle.


Through this process, the system is capable of producing medical grade oxygen of up to 96% consistently. The latest models can be powered from mains electricity supply, 12v DC (Car/Boat etc.), and battery packs making the patient free from relying on using cylinders & other current solutions that put a restriction on time, weight, and size.


Most of the portable oxygen concentrator systems available today provide oxygen on a pulse (on-demand) delivery in order to maximise the purity of the oxygen.


The difference between on-demand & continuous flow

Most portable oxygen concentrators are built from the size of a binocular case and weigh less than a couple of bags of sugar. The reason for this is because of the on-demand system. It allows the concentrator to be built with smaller components than that of a domestic concentrator. Because the patient only inhales oxygen when they breathe in, when exhaling oxygen is wasted. Therefore what manufacturers decided to do is build a machine that works on your breathing… only providing oxygen when necessary, keeping wasted oxygen to a minimum.


Most on-demand portable oxygen concentrators work on settings which are very much equivalent to a specific LPM (Litre per minute). To determine this, the machine works on a bolus system. The bolus size is measured in millilitres and is the “shot” of oxygen released upon inhalation. The size of the bolus on each setting is worked out based on the amount of oxygen inhaled if the patient was on continuous flow oxygen. Since oxygen isn’t required when we exhale, oxygen is normally wasted; hence the reason behind this type of technology.


Technology has progressed in a way so that boluses can be made variable based on the patients breathing rate. This is particularly useful for using an on-demand machine whilst sleeping. Naturally the breathing rate slows whilst sleeping. A machine with a variable bolus detects a slower breathing rate; adjusting the bolus size so that its a longer shot of oxygen upon inhalation, but still maintaining the patients prescription of x amount of litres per minute.


It is not usually recommended that an on-demand device be used during sleep, however clinical studies have found that some on-demand portable oxygen concentrators are just as effective as a continuous flow oxygen concentrator. On-demand devices are not suitable for sleep for patients with the sleeping disorder sleep apnea.

How CPAP machine works?

What is CPAP?

Continuous Positive Airway Pressure and without getting into a lot of physics, the basic principle is that by applying a tight fitting mask and using a regulator designed to provide a high flow of a variable or fixed oxygen concentration and most importantly by attaching a flow restriction device at the exhalation port of the mask, it is possible to have the patient’s airways placed under a constant level of pressure throughout the respiratory cycle.


What do you need to make CPAP work?

  • Oxygen source capable of delivering 50 psi


  • Flow regulator which delivers either a fixed or variable oxygen concentration. The flow generator works by what is known as the venturi effect. When you attach it to the primary regulator of the oxygen cylinder and deliver 50 psi through it, the device “sucks” in room air which is used to dilute the 100% oxygen from the cylinder.


  • Tight fitting mask to which the oxygen/air mixture output of the generator is attached and applied to the patient.


  • Positive End-Expiratory Pressure (PEEP) valve connected to the exhalation port which maintains a constant pressure in the circuit. Each PEEP valve is rated at a certain level measured in centimeters of water (cmH2O) usually in increments of 2.5. The most commonly used levels are 5 or 7.5.


What are the indications for CPAP use?

CPAP is indicated for the treatment of severe respiratory distress seen in chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF) and to a lesser degree in asthma.


How does CPAP work for these conditions? To understand how it works, we need to briefly review the pathophysiology of these conditions.


In COPD, the lung has lost its normal elastic recoil and the alveoli and terminal bronchioles have become stiff with scar tissue. During a COPD exacerbation these terminal bronchioles collapse during exhalation leading to air trapping in the alveoli. This is why the COPD patient breathes through pursed lips and uses active muscle contraction to exhale. By doing so, they are keeping the pressure in the terminal bronchioles elevated to prevent their collapse.


In CHF, the left ventricle fails to keep up with the blood being sent to it from the lungs (preload) and/or the pressure against which it must pump (afterload). This may be the result of an unrecognized heart attack which is now decompensating, uncontrolled hypertension, valvular dysfunction, or fluid overload. Regardless, the pulmonary venous pressures rise and fluid is forced out of the pulmonary capillaries into the interstitial space between the capillaries and the alveoli. The fluid may even fill the alveoli further leading to the inability of the body to absorb oxygen and expel carbon dioxide.


In asthma there is bronchospasm and the work of breathing is increased as the patient strives to move air in and out of the lungs.


The feature common to all three of these conditions is the increased work of breathing and the inability to effectively remove carbon dioxide from the system. As COPD, CHF, and asthma worsens, the patient’s minute ventilation (size of each breath multiplied by the breaths per minute) goes down. Less air movement results in carbon dioxide levels rising which causes a narcotic like effect on the brain further diminishing ventilatory rate. The combined effects of fatigue and rising carbon dioxide in the system leads to further lowering of the ventilatory rate and the patient suffers a respiratory arrest.


What are the indications for CPAP use?

CPAP is indicated for the treatment of severe respiratory distress seen in chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF) and to a lesser degree in asthma.


How does CPAP work for these conditions? To understand how it works, we need to briefly review the pathophysiology of these conditions.


In COPD, the lung has lost its normal elastic recoil and the alveoli and terminal bronchioles have become stiff with scar tissue. During a COPD exacerbation these terminal bronchioles collapse during exhalation leading to air trapping in the alveoli. This is why the COPD patient breathes through pursed lips and uses active muscle contraction to exhale. By doing so, they are keeping the pressure in the terminal bronchioles elevated to prevent their collapse.


In CHF, the left ventricle fails to keep up with the blood being sent to it from the lungs (preload) and/or the pressure against which it must pump (afterload). This may be the result of an unrecognized heart attack which is now decompensating, uncontrolled hypertension, valvular dysfunction, or fluid overload. Regardless, the pulmonary venous pressures rise and fluid is forced out of the pulmonary capillaries into the interstitial space between the capillaries and the alveoli. The fluid may even fill the alveoli further leading to the inability of the body to absorb oxygen and expel carbon dioxide.


In asthma there is bronchospasm and the work of breathing is increased as the patient strives to move air in and out of the lungs.


The feature common to all three of these conditions is the increased work of breathing and the inability to effectively remove carbon dioxide from the system. As COPD, CHF, and asthma worsens, the patient’s minute ventilation (size of each breath multiplied by the breaths per minute) goes down. Less air movement results in carbon dioxide levels rising which causes a narcotic like effect on the brain further diminishing ventilatory rate. The combined effects of fatigue and rising carbon dioxide in the system leads to further lowering of the ventilatory rate and the patient suffers a respiratory arrest.


How does it work?

CPAP works by “splinting” the lungs with a constant pressure of air which reduces the work of breathing. In CHF it forces the excess fluid out of the alveoli and interstitial space back into the vasculature as well as decreases venous return to the heart thereby lessening its workload.


CPAP is not as beneficial for asthma as it is for the other conditions we discussed. Fortunately, it is unlikely to hurt the patient and may help by decreasing the work of breathing. Pneumonia is another condition for which CPAP is not indicated but which may mimic the respiratory distress of COPD or CHF.


However, it too is unlikely to cause any harm and may actually increase aeration of the lungs.


What is the major benefit of CPAP?

The major benefit of CPAP is that it provides the lung ventilatory support while you are administering the specific therapy for the condition. In essence, it buys you time to treat the COPD, CHF, or asthma before the patient arrests. This is a very important point. Once CPAP is started, it is vital that you begin administering bronchodilators to the COPD and asthma patient and lasix and nitroglycerin to the CHF patient. CPAP, by keeping the airways open and facilitating ventilation, increases the delivery of agents such as albuterol to the lung. In CHF, it decreases myocardial workload while you administer nitroglycerin to lower the blood pressure thus reducing both preload and afterload on the heart which further reduces myocardial oxygen demand. What’s the bottom line? CPAP takes the patient who is close to needing intubation and rapidly reverses their condition. Studies have proven that CPAP dramatically reduces the need for intubation which is associated with significant complications and death in these patients.


How CPAP Work Link

What is sleep apnea?


What is sleep apnea?

Sleep apnea affects the way you breathe when you’re sleeping. In untreated sleep apnea, breathing is briefly interrupted or becomes very shallow during sleep. These breathing pauses typically last between 10 to 20 seconds and can occur up to hundreds of times a night.


Untreated sleep apnea prevents you from getting a good night’s sleep. When breathing is paused, you’re jolted out of your natural sleep rhythm. As a consequence, you spend more time in light sleep and less time in the deep, restorative sleep you need to be energetic, mentally sharp, and productive the next day.


This chronic sleep deprivation results in daytime sleepiness, slow reflexes, poor concentration, and an increased risk of accidents. Sleep apnea can also lead to serious health problems over time, including diabetes, high blood pressure, heart disease, stroke, and weight gain. But with treatment, you can control the symptoms, get your sleep back on track, and start enjoying what it’s like to be refreshed and alert every day.


Types of sleep apnea

  • Obstructive sleep apnea is the most common type of sleep apnea. It occurs when the soft tissue in the back of your throat relaxes during sleep, causing a blockage of the airway (as well as loud snoring).


  • Central sleep apnea is a much less common type of sleep apnea that involves the central nervous system, rather than an airway obstruction. It occurs when the brain fails to signal the muscles that control breathing. People with central sleep apnea seldom snore.


  • Complex sleep apnea is a combination of obstructive sleep apnea and central sleep apnea.


Sleep apnea signs and symptoms

It can be tough to identify sleep apnea on your own, since the most prominent symptoms only occur when you’re asleep. But you can get around this difficulty by asking a bed partner to observe your sleep habits or recording yourself during sleep.


Major signs and symptoms of sleep apnea:

  • Loud and chronic snoring
  • Choking, snorting, or gasping during sleep
  • Long pauses in breathing
  • Daytime sleepiness, no matter how much time you spend in bed


Other common signs and symptoms of sleep apnea include:

  • Waking up with a dry mouth or sore throat
  • Morning headaches
  • Restless or fitful sleep
  • Insomnia or nighttime awakenings
  • Going to the bathroom frequently during the night
  • Waking up feeling out of breath
  • Forgetfulness and difficulty concentrating
  • Moodiness, irritability, or depression


Signs and symptoms of sleep apnea in children

While obstructive sleep apnea can be common in children, it’s not always easy to recognize. In addition to continuous loud snoring, children with sleep apnea may adopt strange sleeping positions and suffer from bedwetting, excessive perspiration at night, or night terrors. Children with sleep apnea may also exhibit changes in their daytime behavior, such as:

  • Hyperactivity or inattention
  • Developmental and growth problems
  • Decrease in school performance
  • Irritable, angry, or hostile behavior
  • Breathing through mouth instead of nose


If you suspect your child may have sleep apnea, consult a pediatrician who specializes in sleep disorders. Once obstructive sleep apnea is diagnosed, surgery to remove the child’s tonsils or adenoids usually corrects the problem.


Sleep apnea can be a potentially serious disorder, so if you spot the warning signs, see a doctor right away. An official diagnosis of sleep apnea may require seeing a sleep specialist and a home-based sleep test using a portable monitor or an overnight stay at a sleep clinic.


Is it just snoring or is it sleep apnea?

Not everyone who snores has sleep apnea, and not everyone who has sleep apnea snores. So how do you tell the difference between garden variety snoring and a more serious case of sleep apnea?


The biggest telltale sign is how you feel during the day. Normal snoring doesn’t interfere with the quality of your sleep as much as sleep apnea does, so you’re less likely to suffer from extreme fatigue and sleepiness during the day.


Your answers to this quiz will help you decide whether you may suffer from sleep apnea:

  • Are you a loud and/or regular snorer?
  • Have you ever been observed to gasp or stop breathing during sleep?
  • Do you feel tired or groggy upon awakening, or do you awaken with a headache?
  • Are you often tired or fatigued during the wake time hours?
  • Do you fall asleep sitting, reading, watching TV or driving?
  • Do you often have problems with memory or concentration?


Sleep apnea causes and risk factors

Anyone can have sleep apnea—young, old, male, female, and even children can suffer. However, certain risk factors have been associated with obstructive and central sleep apnea.


Risk factors for obstructive sleep apnea:

  • Overweight
  • Male
  • Related to someone who has sleep apnea
  • Over the age of 65
  • Black, Hispanic, or a Pacific Islander
  • A smoker

Other risk factors for obstructive sleep apnea include certain physical attributes, such as having a thick neck, deviated septum, receding chin, or enlarged tonsils or adenoids (the most common cause of sleep apnea in children). Your airway may be blocked or narrowed during sleep simply because your throat muscles tend to relax more than normal. Allergies or other medical conditions that cause to nasal congestion and blockage can also contribute to sleep apnea.


Risk factors for central sleep apnea

Like obstructive sleep apnea, central sleep apnea is more common in males and people over the age of 65. However, unlike obstructive sleep apnea, central sleep apnea is often associated with serious illness, such as heart disease, stroke, neurological disease, or spinal or brainstem injury.


Self-help treatment options for sleep apnea

While a diagnosis of sleep apnea can be scary, it is a treatable condition. In fact, there are many things you can do on your own to help, particularly for mild to moderate sleep apnea. Home remedies and lifestyle modifications can go a long way in reducing sleep apnea symptoms.
Lifestyle changes that can help sleep apnea:

  • Lose weight. Some people find that even moderate to severe sleep apnea can be completely corrected by losing excess weight. For others, even a small amount of weight loss can open up the throat and improve sleep apnea symptoms.


  • Quit smoking. Smoking is believed to contribute to sleep apnea by increasing inflammation and fluid retention in your throat and upper airway.


  • Avoid alcohol, sleeping pills, and sedatives, especially before bedtime, because they relax the muscles in the throat and interfere with breathing.


  • Avoid caffeine and heavy meals within two hours of going to bed.


  • Maintain regular sleep hours. Sticking to a steady sleep schedule will help you relax and sleep better. Apnea episodes decrease when you get plenty of sleep.


Bedtime tips for preventing sleep apnea

Sleep on your side. Avoid sleeping on your back, as gravity makes it more likely for your tongue and soft tissues to drop and obstruct your airway.


Try the tennis ball trick. In order to keep yourself from rolling onto your back while you sleep, sew a tennis ball into a pocket on the back of your pajama top. Or wedge a pillow stuffed with tennis balls behind your back.

Prop your head up. Elevate the head of your bed by 4 to 6 inches or elevate your body from the waist up by using a foam wedge. You can also use a special cervical pillow.


Open your nasal passages. Try to keep your nasal passages open at night using a nasal dilator, saline spray, breathing strips, or a neti pot.



Medical treatment options for sleep apnea

If your sleep apnea is moderate to severe, or you’ve tried self-help strategies and lifestyle changes without success, it’s important to see a sleep doctor. A sleep specialist can evaluate your symptoms and help you find an effective treatment. Treatment for sleep apnea has come a long way in recent times, so take some time to explore the new options. Even if you were unhappy with sleep apnea treatment in the past, chances are you can find something that works and feels comfortable to you.
Treatments for central and complex sleep apnea usually include:

  • Treating the underlying medical condition causing the apnea, such as a heart or neuromuscular disorder.


  • Using supplemental oxygen while you sleep.


  • Breathing devices that are also used to manage obstructive sleep apnea.


Medications are only available to treat the sleepiness associated with sleep apnea, not the apnea itself, so should only be used in conjunction with other proven sleep apnea treatments.


CPAP for sleep apnea

Continuous Positive Airflow Pressure, or CPAP for short, is the most common treatment for moderate to severe obstructive sleep apnea. In many cases, you’ll experience immediate symptom relief and a huge boost in your mental and physical energy. The CPAP device is a mask-like machine that provides a constant stream of air which keeps your breathing passages open while you sleep. Most CPAP devices are the size of a tissue box.


If you’ve given up on sleep apnea machines in the past because of discomfort, you owe it to yourself to give them a second look. CPAP technology is constantly being updated and improved. The new CPAP devices are lighter, quieter, and more comfortable, so make sure your sleep apnea device is up to date.


CPAP for sleep apnea: tips and troubleshooting

Having trouble with your new sleep apnea device? It can take some time to get accustomed to sleeping while wearing a CPAP device. It’s natural to miss sleeping the “old way,” but there are things you can to do make the adjustment easier.


  • Make sure your CPAP device fits correctly. A correct fit makes a huge difference. Make sure the straps are not too tight or too loose and that the mask seals completely over your nose and mouth. Schedule regular appointments with your doctor to check the fit and evaluate your treatment progress.


  • Ease into it. Start by using your CPAP device for short periods during the day. Use the “ramp” setting to gradually increase air pressure. It’s normal to need several months to get used to sleeping this way.


  • Upgrade your CPAP device with customized options. Customize the mask, tubing and straps to find the right fit. Ask your doctor about soft pads to reduce skin irritation, nasal pillows for nose discomfort, and chin-straps to keep your mouth closed and reduce throat irritation.


  • Use a humidifier to decrease dryness and skin irritation. Try a special face moisturizer for dry skin. Many CPAP devices now come with a built-in humidifier.


  • Try a saline nasal spray or a nasal decongestant for nasal congestion.


  • Keep your mask, tubing and headgear clean. To ensure maximum comfort and benefit, replace CPAP and humidifier filters regularly and keep the unit clean.


  • Mask the sound of the CPAP machine. If the sound of the CPAP machine bothers you, place it beneath the bed reduce the noise. You can also try using a sound machine or white noise machine help you sleep.


Other breathing devices for sleep apnea

In addition to CPAP, there are other adjustable airway pressure devices that a sleep specialist may recommend:

  • Bilevel positive airway pressure (BPAP) devices can be used for those who are unable to adapt to using CPAP, or for central sleep apnea sufferers who need assistance for a weak breathing pattern. This device automatically adjusts the pressure while you’re sleeping, providing more pressure when you inhale, less when you exhale. Some BPAP devices will also automatically deliver a breath if it detects you haven’t taken one for a certain number of seconds.


  • Adaptive servo-ventilation (ASV) can be used for treating central sleep apnea as well as obstructive sleep apnea. The device stores information about your normal breathing pattern and automatically uses airflow pressure to prevent pauses in your breathing while you’re asleep.


Dental devices and surgery for sleep apnea

If you’ve tried CPAP and self-help tips and your sleep apnea persists, you may benefit from a dental device or surgical treatment.


Dental devices for sleep apnea:

Most dental devices are acrylic and fit inside your mouth, much like an athletic mouth guard. Others fit around your head and chin to adjust the position of your lower jaw. Two common oral devices are the mandibular repositioning device and the tongue retaining device. These devices open your airway by bringing your lower jaw or your tongue forward during sleep.


Dental devices are only effective for mild to moderate sleep apnea. There are also a number of troubling side effects from using this type of treatment, including soreness, saliva build-up, nausea, and damage or permanent change in position of the jaw, teeth, and mouth.


It is very important to get fitted by a dentist specializing in sleep apnea, and to see the dentist on a regular basis for any dental problems that may occur. You may also need to periodically have your dentist adjust the mouthpiece to fit better.


Surgery as treatment for sleep apnea:

If you have exhausted other apnea treatment options, you may want to discuss surgical options with your doctor or sleep specialist. Surgery can increase the size of your airway, thus reducing your episodes of sleep apnea.


The surgeon may remove tonsils, adenoids, or excess tissue at the back of the throat or inside the nose. Or, the surgeon may reconstruct the jaw to enlarge the upper airway. Surgery carries risks of complications and infections, and in some rare cases, symptoms can become worse after surgery.