Q:  My husband was on BiPAP® alone, but he starting feeling a lot better when a pulmonologist added oxygen to the treatment. When should people with ALS get oxygen with BiPAP?

Dr. Kasarskis:  The issue depends a great deal on the person’s individual respiratory situation. For a person without any history of lung or breathing problems a non-smoker without asthma or other issues oxygen usually isn’t necessary. People with ALS with essentially healthy lungs may have difficulty moving their chest muscles to bring air into and out of their lungs.  But if their lungs are healthy, the exchange of air (oxygen) between the lungs and the blood (hemoglobin) works well.  If the diaphragm and other muscles are weak from ALS but the lung itself is healthy, then they need assistance with ventilation moving air into the lungs and expelling the waste gas (carbon dioxide) out of their lungs.  These people will benefit from BiPAP (bi-level positive airway pressure, which is non-invasive positive pressure ventilation) at night, but usually will not need oxygen.

It is much more complicated for people with ALS who also have emphysema (COPD), asthma, active cigarette smoking, or other lung and respiratory conditions.  In this situation, oxygen may be needed during the day and oxygen and BiPAP at night.  Other people, especially those who are heavy set, may be prone to obstructive sleep apnea (OSA), which may affect the settings needed to use the BiPAP well.  Even though CPAP (continuous pressure) is the usual treatment for uncomplicated, “regular” OSA, it won’t work for someone with ALS.  Things get very complicated very quickly.

What are the clues that the respiratory system may be affected by ALS?  Of course we measure the breathing status in the clinic, but the most important symptom is probably shortness of breath when trying to lie flat on ones back.  During sleep, others might develop reduced blood oxygen level. This can be measured overnight, either in the home or during a formal sleep study.  Depending on how complicated the individual situation, an overnight sleep study may provide important information to guide treatment with BiPAP or with oxygen if needed.

In short, treatment must be individualized to each person with ALS.  Consultation with an experienced pulmonologist may be helpful in designing the best treatment approach for people with respiratory disease or a history of respiratory problems. Effectively managing ventilation and oxygenation is a central part of treating ALS, since the status of the respiratory system ultimately determines survival with ALS.

Each issue we feature a leading neurologist specializing in ALS responding to a question. If you would like to submit questions for a future Q & A, please send your questions to Amber Walters. Please understand that we won’t be able to address all questions and we won’t be able to respond to individuals personally.