Thursday, May 23, 2013
can you please explain what my pulmonary function test of fev1 85% of predicted, fvc 122 % of predicted and the fev1/fvc ratio of 56 % predicted. can you tell me what those numbers mean? i have quit smoking after these tests were taken. are they ok? for now any way or do i need to start looking for a cemetary plot? (no sarcasm intended. i love my dr. but he doesn`t explain really well an d told me i have mild emphysema."
There are actually 2 parts to these questions that need to be part of the answer:
1) Implications of pulmonary testing as listed
2) The diagnosis of "mild emphysema"
In looking at the first piece of information, pulmonary testing is done to assess mechanical function of the respiratory system. The information it provides supports or refutes but rarely makes a diagnosis all by itself. Testing must be taken in the context of the entire patient and available information. Testing is based on the facts that different kinds of lung disorders can lead to abnormal function which fits into certain patterns.
Some important clinical information such as age, sex, race, presence and/or amount of cigarette smoking or exposures, previous lung problems or testing, the predicted lower limits of normal for these tests based on some of the previous factors, are all lacking information and chest xray results are not present.
For these reasons I will restrict my discussion to general principles.
Current numbers that are provided, if accurate, show what has traditionally been considered a normal FEV1, slightly increased FVC. The ratio of these numbers is stated as 56% of predicted which implies some component of what we call obstruction to flow based purely on numbers stated. Over-interpretation of these results should be cautioned against given the high numbers for FEV1 and FVC. Nonetheless, if accurate and unchanging, the amount of disability under most circumstances expected from these tests would be none or very little. If however, these changes are variable and associated with asthma that periodically worsens, then the patient may experience more symptoms when the asthma is "acting up". Treatment is different depending on the problem.
The diagnosis of emphysema is one which relies on imaging. Pulmonary emphysema is a chronic lung disease, characterized by an abnormal increase in the size of the air spaces which can result in a decrease in lung function and labored breathing. Emphysema is usually caused by exposure to toxic chemicals such as tobacco smoke. Without a picture of the lungs with characteristic findings, the diagnosis of emphysema is incomplete.
Emphysema is one (but not the only) lung problem which may result in altered pulmonary function broadly fitting the pattern described above. Asthma, and small airway obstruction however are others. The amount of dilated air sacs if present may be relevant. It is unclear to me that any imaging (pictures) were taken to confirm this. For most cases, if present, the amount of emphysema expected from these pulmonary test is likely modest at most.
As you can see, interpretation of these numbers and terms must be made in a patient-specific context with lots of information to arrive at an accurate picture. I support and applaud your smoking cessation - keep up the good work!
As with all concerns, I suggest discussion and follow-up with your physician to settle these very good questions.
In general, consultation with a (or an additional) specialist may be useful if important questions and/or concerns remain unanswered or unclear based on your conversations and follow-up with your physician.
Robert Schilz, DO, PhD
Associate Professor of Medicine
School of Medicine
Case Western Reserve University