Q. Why do I need oxygen?

A. Patients with ILD may need supplemental oxygen because of the inflamed or scarred alveolar-capillary membrane, or the interstitial space in the lungs. This makes it more difficult for the oxygen to move from the airsac across the airsac wall and enter the bloodstream, particularly during exertion when the demand for oxygen becomes higher. If your oxygen saturation falls below 89%, this qualifies you for Medicare and other insurers' coverage for oxygen. 'Normal' oxygen saturations are between 97%-99%; in general patients are advised to keep saturations above 88-90%.

Q. What are the benefits of oxygen?

1. decreased shortness of breath
2. decreased strain on the heart (lower heartrate, prevention of pulmonary hypertension)
3. increased activity level
4. improved sleep quality
5. increased ability to be involved in activities outside of the home

Using oxygen may not make your shortness of breath go away; your breathlessness can be due to low oxygen levels, however, even if your oxygen levels are normal, you may still get breathless with activity. This is because of the increased stiffness of the lung due to the inflammation or scarring which creates more 'work of breathing' which you sense as uncomfortable breathing or dyspnea. Other causes of breathlessness include deconditioning and loss of muscle, or excessive body weight.

Q. What if my physician prescribes oxygen but I choose not to use it?

A.  You may experience different symptoms depending on how low your oxygen saturations are, including increased heart rate with activity, increased breathing rate, increased pressure in the lung's blood vessels (pulmonary hypertension) or worsening shortness of breath with activity.

If your oxygen levels are below 89% at rest, there is evidence that using oxygen over 15 hrs/day may improve survival. So if you have low oxygen levels at rest it is important for you to use oxygen as prescribed. If you only have low oxygen levels when you exert yourself, the benefits may vary between patients. There is very little data or research on the long term effects for patients with ILD who do not use supplemental oxygen during episodic or intermittent periods of low oxygen levels, such as during daily exercise. Patients with ILD vary a great deal in terms of how much they desaturate with exertion; some patients do not need supplemental oxygen and others need very high levels. If your oxygen saturations are right around 88% with activity you may not feel the symptoms that another ILD patient might feel with saturations around 80%.

Some patients experience significant benefit to their breathlessness, activity levels, and general quality of life when using oxygen while others may not. This is an important discussion to have with your healthcare providers in order to make the decision for using oxygen and to have realistic expectations for this treatment. Physically managing the equipment, using oxygen in public and around family, and the impact on your day to day life can be significant. However the benefit of staying active, being able to exercise, travel, and be mobile outside of your home can be significant.

Q. What kinds of oxygen are available?

A. Oxygen is available in three forms:

1. Compressed gas:  This form of oxygen comes in hard, green, metal cylinders. These cylinders come in multiple sizes (C, D, or E) tanks, or very small cylinders around the size of a wine bottle ( M4, M6, M9, or ML4, ML6). The smaller ones can be carried in a backpack or purse; the larger ones (E tanks) are pulled on a wheeled trolley. When using a compressed gas cylinder, a regulator is attached to it that allows you to turn it on and off and to set the flow rates. Some regulators can switch between intermittent (pulse) and continuous flow (discussed below).
   
2. Liquid oxygen (LOX): This is a form of oxygen that has been super cooled until it becomes a liquid and is then stored inside a large reservoir tank; smaller portable canisters are filled as needed from this large tank. When this liquid oxygen is exposed to air it changes to a gaseous form. Compared to compressed gas cylinders, portable liquid oxygen canisters can hold more oxygen due to its concentrated form. The smaller portable devices are also capable of providing high continuous flow (>4 Liters/min). Liquid oxygen is not as readily available from Durable Medical Equipment (DME) companies as the compressed gas cylinders and concentrators, primarily due to its higher cost of weekly deliveries, the need for special equipment, and servicing.
   
3. Oxygen Concentrators: Oxygen concentrators, both the stationary and small portable types, take oxygen from the air around you ("room air") and draw that air in through special sieves, or filters, that remove the nitrogen and produce 'concentrated' oxygen. The concentration of the oxygen in the air that we breathe at sea level is 21%; an oxygen concentrator can purify that oxygen to about 94-97%. The in-home concentrators (stationary) plug into the wall and use electricity, while the portable oxygen concentrators (POCs) use a battery that is rechargeable, and can be plugged into a wall outlet to charge. POCs vary in that some can switch between pulse and continuous flow, while others are only pulse flow. POCs are limited in continuous flow and currently only go to 3 liters/minute on continuous flow, whereas metal canisters can go up to 10 L/min. or more. Stationary concentrators are available in two capacities; one goes up to 5L/min and the high-flow ones can go up to 10 L/min).

Q. What are the different types of flows on oxygen equipment?

A. There are two basic types of flow on oxygen devices:

1. Continuous flow (CF): This type of oxygen flow means that oxygen is flowing at the same rate the entire time that you are breathing, whether you are inhaling or exhaling. It is ordered in liters per minute or L/min. Continuous flow is always used during sleep, although recently there are some POCs with pulse flow that are described as being sensitive enough to trigger during sleep. All stationary concentrators only use continuous flow. Some POCs and compressed gas canisters can be switched between pulse flow and continuous flow. Some POCs only provide intermittent flow.
2. Pulse flow (intermittent or demand flow): On this setting, oxygen only flows during the inspiratory (inhalation) phase of your breathing- the device is triggered to deliver oxygen by each of your breaths. While you exhale no oxygen is flowing. Some pulse devices are set to deliver the same pulse dose of oxygen for each breath no matter how fast you are breathing (number of breaths per minute), while other pulse devices are set to deliver a set volume of oxygen each minute. In the latter, the faster you breathe per minute, the lower dose of oxygen you get with each breath. Pulse devices do not deliver L/min, but instead use number settings of 1, 2, 3, etc...Pulse can be used with compressed gas cylinders, liquid oxygen canisters, and also with POCs. The advantage of pulse devices is that they conserve oxygen by allowing the tank or POC battery to last longer as they are only delivering oxygen during inspiration. 

Q. What are the advantages of using a device with pulse or intermittent flow?

A. The main advantage is that pulse devices prolong the time that either a tank or a POC battery will last. Using pulse settings on compressed gas cylinders makes them last longer when you are out of the house. Using pulse on POCs will make the battery last longer compared to using that POC on a CF setting. POCs can be charged anywhere by plugging into the wall (or even a car lighter), and don't 'run out' of oxygen, but the higher the setting on a POC, the shorter the battery life.  

Q. What are the disadvantages of using a device with intermittent flow?

A. The disadvantage of using pulse settings is that in some patients this mode does not maintain oxygen saturations above 88-90%. Pulse devices are often not adequate to keep saturations >88% in patients who need oxygen >4 L/min CF, and during times of rapid respiratory rates when the POC may not ‘trigger’ properly.. Currently the highest pulse flow available on POCs is 6, but patients may find that their saturations with exertion on 6 pulse are lower than when using oxygen at 6 L/min on a CF device. Another potential disadvantage of pulse is that during exertion or episodes of breathlessness when you may breathe with a very rapid but shallow breathing pattern, the pulse device may not consistently trigger.

Q. How do I know if the oxygen device I receive or choose is effective for me?

A. The most important thing to remember is that no matter what type of oxygen device you receive or choose from your Durable Medical Equipment (DME) oxygen company, you need to be tested on that device both at rest sitting quietly, and also during periods of exercise or activity, to make sure that the equipment is adequate for you and keeps your oxygen saturations above 88-90%. Always take your portable equipment with you to your doctor's appointment; the physician, nurse or medical assistant can walk you and check your oxygen saturations on your equipment. You should also do this yourself at home when you exercise or walk. Make a note of what setting your equipment is on and check your pulse oximeter readings when resting, and again during or immediately after periods of exercise or exertion. Share this information with your healthcare provider, especially if you note any significant changes.

Oxygen Saturation Testing

Six Minute Walk Test: Typically, patients with ILD are first prescribed oxygen only during exertion. Depending upon the results of your testing, you may be advised to use oxygen 24 hrs./day whether you are active, resting, or sleeping.

The six minute walk test is used to assess your oxygen saturations while walking at a pace to cover as much distance as possible during six minutes. A pulse oximeter, placed either on your finger or your forehead (for those with poor circulation to their fingers), is used to measure your oxygen saturations before you begin walking, and right at the end. If your oxygen saturation levels drop to 88% or lower, you qualify for supplemental oxygen with activity. The six minute walk test also is used to measure and monitor your exercise capacity- the number of feet that you were able to walk in six minutes. Both oxygen levels and walking distance can be monitored over time as additional assessments of your lung disease.

Exercise Oximetry Testing:  Exercise oximetry testing can be done to determine if you need oxygen with exertion, and exactly how much you need to keep your saturations above 88%. If you desaturate during a Six Minute Walk test, the therapist will walk you again while using oxygen to determine how much that you need (liter flow or number setting) to keep your saturations above 88% (exercise oximetry testing). Exertion includes exercise at a gym, pulmonary rehabilitation, or during activities around the house or at work. Showering, gardening, and housework such as vacuuming are types of exertion that may require you to use oxygen.

Arterial Blood Gas (ABG): You may have your oxygen levels directly measured by having an arterial blood sample drawn from your radial artery in your wrist. The artery contains blood that is fully oxygenated and normally is 97-99mmHg- the partial pressure that the oxygen exerts in the blood.

Overnight Oximetry Testing:  Your clinician may want to confirm if your oxygen levels drop while you sleep, especially if you need oxygen while resting or even just with exerting yourself.  This test can be ordered through your oxygen equipment company who will place a special type of oximeter on your finger overnight and will return to pick it up the next day.  The information will be downloaded to see if and how often your oxygen saturations dropped below 88-90% during sleep.  This will assist in determining the appropriate amount of oxygen to use if needed.  This test does not diagnose obstructive sleep apnea; that test requires more sophisticated equipment and is done in a sleep testing center.

Initial Oxygen Orders:  Once it is determined that you need oxygen, your physician or healthcare provider will place orders with a local Durable Medical Equipment (DME) company. 

These orders will include your oxygen saturation readings at rest without oxygen, during exertion without oxygen, and during exertion with oxygen.  Importantly, this testing must be done within 30 days of a 'face to face' visit with your physician.

The orders will include the type of portable oxygen system for use outside the home, and also a 'stationary' oxygen system for use inside the home.

Your oxygen orders will also include what liter flow or setting to use with:

1. rest
2. exertion
3. sleep

Equipment: Some insurers only cover certain types of oxygen equipment so it may take some communication back and forth between your DME and the MD office and you to finally determine what your options are.  If there is a particular light weight or other type of equipment that the DME does not supply, you can ask to check with other DMEs in your area to see if they offer something different.  This is important as once you begin the 5 year contract period using the delivered oxygen equipment, it is difficult to change equipment AND difficult to change companies.   

Oxygen Prescription:  As the patient, it is key for you to know what equipment was ordered, and what liter flow to use, as well as what level your MD would like you to keep your oxygen saturations, i.e. above 90%.

Air Travel with Oxygen

The only type of portable oxygen that is allowed on airplanes is a portable oxygen concentrator (POC). Most POCs are FDA-approved for air flight and a recent listing of POCs for air travel can be found here. Recently, POCs are being stamped with an FDA approval notation. However, there are important points to consider when you are a supplemental oxygen user and planning to travel by air.

1. First, check with your physician to make sure it is safe for you to fly with your lung condition. This is particularly important if you have recently been sick, undergone any procedures, or also have heart problems.
   
2. Traveling by air simulates high altitude because oxygen concentrations in the plane's cabin are lower compared to those at sea level. The airline cabins are pressurized to about 8,000 feet above sea level and for some ILD patients this may significantly decrease oxygen saturations.
   1. If you don't need oxygen normally, but are borderline, you can have a "High Altitude Simulation Test" to see what your oxygen levels are at altitude. This test is done by having you breathe in a mixture of oxygen that is 17% oxygen instead of the normal 21% oxygen. Your physician will review the results and advise you if you will need oxygen during the flight, and how much.
   2. If you already use oxygen at sea level, you will likely require a higher setting during your flight. Talk to your physician to confirm what setting to use.
3.     Check the airline's website at least one month before you travel to determine if they require an MD letter documenting that you are physically able to use a POC during flight, what setting, and that you will have enough battery power for the flight. (Most airlines require that you have 1 1/2 times the hours of the flight in terms of hours of oxygen supply. You should take a few copies of this letter with you.
4.     Notify your physician at least one month before you travel  so that they can have the required documentation ready for you. 
   
5.     Check with your DME if you do not currently use a POC and see if they can rent you one for your trip. If they can't, there are other sources that specialize in traveling with oxygen. Make sure you have extra batteries.
6.     Check with the airlines to confirm if you will be in a seat that you can plug in to charge your POC.
7.     When you arrive at the airport, plug in while waiting for your flight so that you can save your battery for the flight.
8. In addition to arranging for a POC during your flight, if you use oxygen with sleep or 24 hrs/day you will need to make arrangements for a stationary concentrator to be delivered to you destination.

1. Publications of Interest on Oxygen:   

• Patients Perceptions of the Adequacy of Supplemental Oxygen Therapy:  Results of the American Thoracic Society Nursing Assembly Oxygen Working Group SurveY (PDF)
• American Thoracic Society Official Workshop Report:  Optimizing Supplemental Oxygen Therapy (PDF)
• Effect of ambulatory oxygen on quality of life for patients with fibrotic lung disease (AmbOx): a prospective, open-label, mixed-method, crossover randomised controlled trial
  

2. General Oxygen Information:

• Quick Start Guide for Supplemental Oxygen (Pulmonary Fibrosis Foundation-PFF)
  
• Webinar on Oxygen Equipment (PFF) 
  
• Website with overview of oxygen products
• Quarterly publication for patients with chronic lung disease- excellent resource, 1 (800) 950-3698
• Information on eyeglasses that conceal an oxygen cannula (low flow only), 1 (877) 699-8439 
  
• Supplemental Oxygen  Information booklet with info on reporting problems (PDF)
  
• Oxygen Education video
  
• Website with unique oxygen carrying bags/purses/backpacks
  
• American Thoracic Society (ATS) Patient Information Series "Oxygen Therapy"  (PDF)
  
• POC Information Sheet  (PDF)

3. Travel:

• Travel Oxygen Brochure- PFF
  
• Sea Puffers Cruises:
• Travel O2, 1 (800) 391-2041  
  
• Advanced Aeromedical- rents equipment for travel including international, 1 (800) 346-3556
• Travel and international travel assistance
  

4. Pulse Oximeters:

• Nonin pulse oximeter, 1 (800) 882-8889
• ATS Patient Information Series "Pulse Oximeters" (PDF)
  
• General pulse oximetry info 
  

5. Legislative and Patient Advocacy Information

• Changes in Medicare Competitive Bidding program