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Archive: Dr. Tom 12
Posted March 3rd, 2005

Carbon Dioxide Build-Up
Q. A hospice member of our group asks about carbon dioxide buildup. She quotes your “Enjoying Life...” page 78, as warning about the danger of too much oxygen and carbon dioxide buildup.

Subsequent books, yours and other more recent books, don't appear to have such a warning. Is this no longer regarded as a problem? Should she not worry about it? (Usually, she is one and one-half to two liters.) Thanks.


A. Dear John, I should not have been so dogmatic about C02 buildup. It is only harmful if it goes up fast, and this is usually due to what we call an “exacerbation,” i.e. a sudden worsening of COPD.

Actually it is not the oxygen that drives up the C02, as was previously believed, but the fatigue of the patient, resulting in rapid shallow breathing. In advanced stages of COPD, the body adjusts to the effort of breathing by letting the C02 go up gradually, and this makes its elimination more efficient—more CO2 per breath, more exhaled.

The kidneys compensate for this slow elevated CO2 to keep the blood acid level at or near the normal range. This whole process may be accompanied by a relief of shortness of breath that is pleasant for the patient.

Long answer to a complex question. Bottom line: do not worry about the CO2 level when you are on oxygen at a controlled level of 1-3 liters and are not feeling ill.

Dr Tom


Blood Pressure
Q. My blood pressure is 133/115. What dose this mean?


A. Dear Alex, Take it again. That is a strange blood pressure. The high number (133), representing the force of contraction of the heart, is normal. The low number (115) represents the resting blood pressure in your arteries between heart beats are quite high. This needs an explanation. Most likely these numbers are wrong.

Dr Tom


Basilar Lung Scarring
Q. I have developed basilar lung scarring (both lungs) within the last two years. I’ve never had pneumonia and have never smoked. Two MD's reviewed the CT. One was concerned and the other was not. What should I do?


A. Dear Maria, The scarring is an x-ray shadow, which may or may not be important. This tells nothing about your lung function.

Get a lung function test called spirometry. Only two numbers are important: the FVC (Forced Vital Capacity), which measures lung volume, and FEV1 (Forced Expiratory Volume in 1 second), which measures lung flow. Let me know the results.

Dr Tom


Q. Is pneumonia contagious? My girlfriend had it and not long after being in contact with her I got it. She was very sick first, with a bad cold. Then I got the cold, then the pneumonia, just like her.


A. Dear Jackie, Many pneumonias are infectious. Both bacteria and viruses are easily spread by sneezing, coughing, or on the hands.

Dr Tom


Bullae Lung Disease
Q. I have another question. My pulmonologist has diagnosed me with emphysema. He says that it is not just Bullae Lung Disease. His reasoning for this is that he had noted a few spots on my lower lobes from the CAT scan that he says are emphysema.

Is there any way this can be a false reading on his part and is this the only way you can detect if a person has emphysema at this point? My previous post to you had stated that my PFT numbers's were all over 80 with the exception of FEV1/FVC= 73%. My FEV1 was 82%. My test was interpreted as borderline obstruction with normal diffusion.

My CAT scan showed severe bullous emphysema of the right upper lung as well as a bullae on the upper left lung. I am 42 years old, 5'11'' 210 lbs.


A. Dear Bob, These tests are convincing that you do NOT have diffuse emphysema. Only localized areas of bullae. You do not need to have anything done about them as long as you feel well and your lung functions are normal. I do not agree that your lung function is abnormal at all.

Dr Tom

See Bob‘s original question.

Bob's Original Question
Bullous Emphysema
Q. Dr. Tom
I would like to know if there is a way to differentiate between bullous (enlarged air sacks) lung disease and bullous emphysema? As far as that goes is there a different prognosis for bullous emphysema and the more common type? Thanks, Bob


A. Dear Bob, Bullous lung disease may occur without emphysema, or with it. Lung function tests help to distinguish between the two.

In isolated bullous disease your airflows are normal, unless giant bullae take up too much lung space, i.e. vital capacity. CT scans can also distinguish major isolated bullae from the bullae associated with diffuse emphysema.

Dr. Tom


Pulmonary Function Test
Q. When I do the PFT tests, I cannot get results from the DLCO tests. I was told that I could not perform this test. What does that mean?


A. Dear Henrietta, It just means that you could not hold your breath long enough to transfer the indicator gas into the system. It does NOT mean that there is anything wrong with your ability to move gases from the airside to the capillaries in your blood. It only means that they could not measure this function.

Dr Tom


Coughing Up
Q. I recently coughed up some small particles. They were a little like popcorn. What do you think is causing this?


A. Dear Ruth, They were probably particles of dried mucus.

Dr Tom



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