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Archive: Dr. Tom 69
Posted July 11, 2006

Readers: Read Dr. Tom’s Commentary on Spirometry to understand the importance of this diagnostic lung test.


A Bubbling Feeling in Lungs
Q. I have a bubbling feeling in my left lung, what could it be?


A. Dear Lisa, This sounds like a leak of air from the lung into the space around the lung, known as the pleural space. The medical term for this condition is a pneumothorax. It can be easily diagnosed by a simple chest x-ray, done in the act of expiration. It is often self-limited. In cases of a large accumulation of air, a small tube may be used to remove it.

Dr Tom                        

Is there a Relationship Between CPAP and Central Sleep Apnea?
Q. It is sometimes stated in sleep medicine that increasing the CPAP machine (a machine used to help keep the airways open during sleep) to higher than optimal pressures can induce central sleep apnea (is when you stop breathing during sleep and is caused by problems with how the brain controls breathing).

Is this true and how does this happen physiologically? I thought the opposite would happen since increasing CPAP increases the FRC (Functional Residual Capacity is the volume of air remaining in your lungs at the end of normal expiration) and therefore pCO2 which in turn would stimulate breathing.


A. Dear Leo, Increasing the FRC should not cause a rise in the PCO2. CPAP does some support of ventilation and is used, as you know, to combat --------sleep apnea. CPAP does some work of breathing. BiPAP (Bi-Level Positive Airway Pressure is a technique that is often used to treat sleep apnea and to provide airway support with a face mask rather than tracheal tube that is attached to a mechanical ventilator) provides more ventilatory experience and is more appropriate for central sleep apnea.

Dr Tom

Oxygen Liter Flow for Facemasks
A. As a result of multiple heart attacks my father has 25 percent heart and lung function. He takes oxygen as needed thru a nasal cannula. He has terrible nosebleeds, and recently we took him to the emergency room and they packed both nostrils.

My dad has COPD. We asked the doctor how he would receive his oxygen with both his nostrils packed. The respiratory therapist came in with a facemask and told us that it must be set at five liters. When he was on the nasal cannula I think he was on 2 liters.

We were trying to explain what we had been told by the respiratory therapist. The nurse did not understand and we were having trouble explaining to her that his nasal cannula could be 3 liters but we were told the facemask has to be 5 liters. Can you explain to me why this is?


A. Dear Susan, There is no direct relation between the liter flow by nasal cannula and a facemask. Both are open systems, meaning that the oxygen flow is diluted by the patient's own breathing. The facemask is more open, and allows more dilution, however the results of the oxygen administration can easily be monitored by pulse oxymetry (a machine that measures your oxygenation).

Dr Tom

Asthma and Bronchitis
Q. Are bronchitis and asthma related?


A. Dear Helen, Yes, both are inflammatory processes of the conducting airways of the lungs. The mechanisms of inflammation in asthma are different from the inflammation caused by smoking, the most common cause of chronic bronchitis. The two may occur together and are called, asthmatic bronchitis.

Dr Tom

Inflammation Seen on Lung Scan
Q. Dr. Tom, I had a lung scan done and all they found was an area they called inflammation, which they said was due probably to a cold? Is this anything to worry about or is this common?


 A. Dear Bill, This is common, but you should be sure that it resolves by having a follow-up exam.

Dr Tom

What Does ‘Early’ Emphysema Mean?
Q. My wife recently had a chest x-ray. She has been having difficulty breathing and pain with it. The results were hyperinflated lungs without lesions. Early emphysema, she is 40. She quit smoking about 10 months ago. What exactly does this mean? 


A. Dear James, Not much. Early emphysema cannot be diagnosed by a chest x-ray. Your wife should have simple spirometry to measure her airflow and volume (see the National Lung Health Education Program) .

Dr Tom

Shortness of Breath and Other Symptoms
Q. Since March 2006, I have had shortness of breath, and the past month I have gained ten pounds and gone from a size 4/6 waist to a 10/12 waist.  I have also been lethargic and moody. My lower back hurts often and the discomfort is radiating down my left hamstring.  I am a 41 year old female.  What do you think it could be?  Thanks in advance for your input.


A. Dear Karen, It is hard to tell from the information you stated. You need to see a doctor and get a diagnosis.

Dr Tom

Do you Need a Doctor’s Order to Buy a Pulse Oximeter?
Q. I am a second year respiratory therapy student. I wanted to purchase a Nonin Onyx pulse oximeter, but I was told that only doctors can buy them. Any advice...thank you.


A. Dear Ken, No, you can buy these directly. They are commonly used in sports medicine and do not require a prescription.

Dr Tom 

Traveling with Oxygen
Q. I have a friend with end stage COPD and O2.  He wants to fly back East and rent a car.  Problem is he would have to take an empty cylinder on the flight, but how could he get it refilled to travel to his family’s place after arrival. The home O2 company will have the equipment at the house, but he wants to have his own car.  He's a stubborn mule. Thanks for your time and attention.


A. Dear Lani, There are two light weight oxygen concentrators that can be taken on aircraft that weigh about 10 pounds and are battery or A/C powered. You need to get one from your supplier and be sure the airline approves of this on their flights. The devices are the Inogen and the LifeStyle. Other light-weight concentrators are soon to be released. 

Dr Tom

Portable and Wearable Oxygen Devices
Q. Dear Dr Petty, At the recommendations of the 6th long term O2 consensus conference you mentioned the absence of consensus regarding portable versus wearable O2 sources. Actually what are the criteria to separate these two systems? Weight only or  also new device like jacket with O2 inside, a really wearable system?

Do you known any reference regarding such research?

Thank you very much for your answer and for all your medical contributions.


A. Dear Patrick, Thanks for your question and compliment. Wearable is a weight issue. The Helios and Spirit weigh about 2KG (4.4 pounds), and are easy to wear on the body. There is no oxygen jacket, but I have long wondered about making such a device. The conference debate about the weight of a truly wearable system; some wanted it to be as much as 4.5KG, ten pounds, but this is too heavy for most people to wear.

Dr Tom

Q. Can I use Spiriva and Xopenex at the same time?


A. Dear Robert, Yes, they are different bronchodilators that use specific mechanisms. They are perfectly compatible.

Dr Tom

CT Scan Results have Me Worried
Q. Dear Dr. Tom, I am a former smoker (I quit smoking in 2004 after 25 years of smoking).  Two years ago my Dr. found a lung nodule on my left lower lobe. (from a CT scan). There are now 4 lung nodules on both lungs in both lower lobes.  They are smaller than 4mm and the largest is 3.5mm.

My Dr. does not seem concerned although I am scared as my husband had NSLC two years ago.  He had a lung resection of the left lung lower lobe and went through chemo. He was a T2L1M0.  He presently is in remission.  We have three small children ages ten, eight, and three.

 My Dr. said he will do another scan in 12 months and not to worry because there is nothing anyone can do right now as the nodules are not even large enough for a biopsy.  Can you please give me some advice on this and what I can do about this?


A. Dear Ruth, These are most likely benign. I would rescan in 6 months and not worry in the interval.

Dr Tom

Doctors have Conflicting Opinions on Medications
Q. Dr. Tom, About three or four months ago, my doctor put me on Spiriva. He already had me on Advair Diskus and Combivent. I was recently hospitalized for pneumonia and the doctors there said that was not a good combination. They prescribed albuterol and told me to discontinue Combivent. What should I do?


A. Dear Bill, Spiriva and Advair are compatible and are commonly used together. Combivent contains two short acting bronchodilators, that are in the same class as Spiriva and is the bronchodilator component of Advair. But it is not wrong to take Combivent for short time relief of a breakthrough attack.

Dr Tom

2024 American Association for Respiratory Care