This web site is mainly devoted to chest physiotherapy and breathing training, and will not be discussing COPD oxygen and medication therapy in detail. These modalities are generally derived from prescriptions written by your physician. Questions about oxygen or your various medications should be referred to your doctor. In the COPD Links module a number of references will be given that discuss these topics in greater detail.
As to medications, it is important that you take them regularly, in the prescribed manner. It is surprising how many patients take their medications irregularly, or confuse one medication for another. And with regard to your inhaled aerosol drugs or Metered Dose Inhalers, previous modules have stressed the importance of exhaling effectively. You must do this in order to correct Dynamic Hyperinflation and lung overinflation problems, in order that you may achieve a larger breath volume, to more effectively carry the medication deep into your lungs. This is particularly important if you are having an acute episode of increased dyspnea.
Oxygen therapy needs to be discussed in greater detail, as adequate oxygen is now known to be critically important to your general health, and in fact how long you will survive. Unfortunately, oxygen deficiency and the need for supplemental oxygen therapy can be subtle, and quite variable, and dependent on various circumstances which you need to understand.
Remember, the lungs have two basic functions. The first is to get waste Carbon Dioxide removed from your body, and much of our discussion of breathing training up to this time has been concerned with this function. The second is to get the vital energy source of Oxygen into your body, and this process has been linked to breathing patterns.
As previously discussed, it has long been known that slower breathing, with a larger Tidal Volume breath volume generally improves oxygen transfer into the body, and biofeedback training with oxygen measuring devices have been used to alter breathing patterns to improve blood Oxygen Saturation. Furthermore, an end-inspiratory breath hold pause should improve oxygenation, by means of improved alveolar collateral ventilation, at least in some patients with a low blood Oxygen Saturation. It has become apparent that breathing patterns play a small but significant role in improving blood oxygenation.
It is critically important that the adequacy of your oxygen level be diagnosed, as clinical diagnosis of a low qxygen level is very difficult and unreliable, except in severe levels of blood Oxygen Desaturation, called Hypoxia. It is very easy to miss a diagnosis of moderately severe, but clinically important hypoxia.
This may present some difficulties. The most accurate way is a direct Arterial Blood Gas analysis. The simple common venous blood sample unfortunately is not adequate for blood Oxygen and CO2 measurement. If the oxygen level is sufficiently deficient while you are resting quietly, the diagnosis of hypoxia (i.e. low oxygen) is easily made. Hypoxia may also be diagnosed indirectly, by sampling through the skin or a fingernail, by a device known as an Oximeter, which measures the so-called Oxygen Saturation (or commonly referred to as the "O2 Sat") of the blood, expressed as a percent saturation. Oximeters are very convenient, though slightly less accurate, and avoids the sometimes uncomfortable direct sampling required when putting a needle into an artery. Fortunately small portable Oximeters suitable for home use, and reasonably priced, have become available.
However, to complicate this situation, an adequate level of oxygenation while you are resting quietly does not completely exclude the diagnosis of significant hypoxia. At the present time, based on some old studies, hypoxia is diagnosed to be qualified for oxygen therapy reimbursement by blood oxygen levels at rest. There is widespread concern in the pulmonary physician community that some patients would benefit by broadening the definition of hypoxia for different circumstances other than simple resting hypoxia. Recommendations of an expert study group for further research in this area were published in July 2006, and hopefully future research will clarify these issues.
Exertion Hypoxia is common, and to diagnose this situation requires a controlled exercise stress. Exercise stress may be safely provided by walking (e.g. the Six Minute Walking Test, or similar tests), Stair Climbing, Bicycle Ergometry (i.e. a specially calibrated stationary exercise bicycle), or a stationary exercise walking Treadmill. Your physician and other trained personnel monitor you continuously with safety precautions. And if a Bicycle Ergometer or Treadmill is used, as an extra precaution, a continuous Electrocardiogram (EKG) of your heart is commonly performed, along with continuous Oximetry measurements. Should significant hypoxia develop, supplemental oxygen may be provided, and the exact amount necessary may re determined.
Sleep Hypoxia is also fairly common, and may be due to other problems than COPD which may need to be treated. The various conditions may be diagnosed with a formal "Sleep Study." This requires you to spend the night at a Sleep Laboratory. Multiple sensors may permit a more detailed diagnosis as to why hypoxia is developing, and a more specific therapeutic program, in addition to defining the oxygen supplement level needed to resolve your hypoxia problem. Partial diagnostic sleep studies may be done at home, using only recording oximeters, and follow-up studies may define whether or not your oxygen supplement level is appropriate.
High Altitude Hypoxia is rather difficult to define, as it really depends on whether your lungs and Oxygen Saturations are normal, and whether or not the altitude stress is acute or chronic. With altitude there is less atmospheric pressure to drive oxygen into the body, in essence creating a situation of relatively less available oxygen.
Normal people in Denver (altitude about 5000 feet, the "Mile High" city) have oxygen levels in the mild hypoxia region, and they get along just fine. However, people with COPD and low or marginally normal levels of Oxygen Saturation, may be significantly hypoxic if they go to altitudes of 1000 to 2000 feet above sea level. Commercial aircraft are artificially pressurized to a level of about 5000 to 8000 feet, and obviously COPD patients at risk must take oxygen precautions when flying. In the COPD Links module you will find advice about travel by air, and the problems of how to provide for oxygen so you can travel safely. If there is any question about your ability to fly safely, you should have a test called the Hypoxia Altitude Simulation Test (HAST), also referred to as the Hypoxia Inhalation Test (HIT). This test involves breathing a low oxygen gas that simulates the low oxygen levels during commercial air travel, and permits a definition of how much supplemental oxygen you will need to travel safely.
Hard and prolonged coughing attacks, especially if they induce choking spells, may cause acute hypoxia, and precautionary temporary oxygen may be advisable.
Bronchitic Exacerbations, and other cardiac and pulmonary problems frequently make patients hypoxic. Unexplained and progressive hypoxia can be an early warning signal of a developing COPD complication requiring medical attention.
Looking at all these potential hypoxic situations one must ask, how is it possible to be certain you are getting adequate supplemental oxygen, and particularly so for the patients on continuous Long Term Oxygen Therapy ("LTOT"). The answer to this question is the development of the portable personal oximeter, for individual use, and therefore the immediate availability of O2 Sat readings whenever one is in doubt. With a price of just over $200 they are an excellent investment for the COPD patient who has any questions about their oxygen needs. A simple and reliable oximeter is the Nonin Onyx 9500 Digital Fingertip Pulse Oximeter. Ordinarily these devices are dispensed via a medical prescription and may be purchased from multiple medical supply sources. The Med1Online web site http://www.med1online.com sells this device without a prescription.
Oxygen is not only vital to your health, it is also expensive. It is now well documented that many hypoxic COPD patients may increase their Oxygen Saturation levels about 4 to 5% with proper breathing patterns. And there is anecdotal evidence of some more severely hypoxic patients who are able to increase their O2 Sats as much as 8% with appropriate breathing strategies.
Think about the implications of this very carefully. If you run out of oxygen, or feel the need for more oxygen, correct breathing may bring your O2 Sats up to an acceptable level. And as to cost savings for expensive oxygen, the ability to reduce your oxygen flow by even 1/2 to 1 liters per minute is going to make quite a savings over a year or so.
It makes a lot of sense for the COPD patient on oxygen therapy, and particularly those on continuous Long Term Oxygen Therapy, to master efficient breathing patterns. As discussed in previous modules, experiment with the Breathing Trainer adjustments and find a comfortable COPD breathing pattern with a slower respiratory breathing Rate, a larger Tidal Volume breath size, and a longer Expiratory Time of at least 60% or more. Then, try increasing the End-inspiration Pause time from about 5% to 10% or 15% and see if your O2 Saturations improve.