Monthly Letters to Pulmonary Patients by Thomas L. Petty

Thomas L. Petty, M.D.

Professor of Medicine, 
University of Colorado

Chairman, National Lung Health Education Program (NLHEP)


National Lung Health Education Program
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HealthOne Center
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Denver, CO 80218
Phone: 303 839 6755
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Ambulatory Oxygen: 
Keep Tuned for Further News

Special Letter
PEP Pioneers
Second Wind
Torrance, California

     Dear Friends:

The value of ambulatory oxygen in patients with advanced COPD and related disorders began to be established almost exactly 33 years ago in original studies done in Denver, with the first prototype Linde-Walker systems.  Our studies, followed by those of many others, has clearly established ambulatory oxygen as the standard of care for patients who are able to benefit from exercise, and get outside of the home to participate in activities of daily living, including work and recreation.  Hundreds of thousands of people worldwide have benefitted from ambulatory liquid oxygen.  Unfortunately, an e-cylinder gaseous oxygen source is neither convenient nor practical for the majority of patients.  Pulling an e-cylinder on wheels is hardly ambulatory in the sense of freedom for full activities.  In fact, there are many instances of injuries associated with tripping over a tank or delivery tubing.

Unfortunately, portable liquid oxygen is more expensive than oxygen delivered by an oxygen concentrator.  Studies strongly suggest that the ability to ambulate has global value for patients, probably because it improves exercise capability and fosters social interactions.  Also, the Heath Care Finance Administration (HCFA) has failed to recognize portable liquid oxygen’s real advantage. Reduction in reimbursement for oxygen in general has caused many suppliers to discontinue liquid oxygen because of loss of profitability.  The most efficient suppliers, however, are still able to provide liquid oxygen.  Many suppliers tell patients that Medicare will not pay for liquid portable oxygen, but this is not true.  It is a fact that reimbursement for liquid oxygen does not produce as much profitability.  It is also a fact that a physician’s prescription cannot be changed by the supplier.  So, all patients need to hold out for their liquid portable oxygen at the present time.

Now, to the future:  I am now working with a company in Denver which has a device  with the ability to make liquid oxygen by diverting a small portion of the liter flow from an ordinary concentrator.  This device can make .8 pound of oxygen per day, which is about a six to ten hours supply at 2 liters per minute, depending upon whether a conserving system is used.  Thus, it may be possible for patients to have their own liquid oxygen generator in the home someday soon.  So far, the device is in its developmental stages.  If successful, it may help solve the problem of supplying liquid portable oxygen in the home for patient ambulation.  Other technologies may result in lower weight concentrators.  Current motor and battery technologies might allow for development of a light weight concentrator with about four hours supply outside of the home.  Neither of these devices are ready for market yet, but they are under intense study.

I wanted to let you know about these new developments, since they should encourage us all to continue to push for ambulatory liquid oxygen because of the established good that it does.  A third of a century of study in ambulatory oxygen should not be denied.  We must always push to maintain what we have, or to improve it through new technological developments.

I will be in touch next month.

     Your friend,

    Thomas Petty, MD

Last update:
14 March 2002
Contact information:
Box 1133 Lomita, California 90717-5133
Fax   (310) 539 - 8390
Tel (310) 539-8390