What is emphysema? What is Asthma?

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Emphysema is physical destruction of lung tissue that results in obstruction to air flow and development of enlarged air sacs. Emphysema is a smoking related disease that causes progressive obstruction of the airways and destruction of lung tissue. Because the airway is obstructed, more energy is required to ventilate the lungs. The patient will experience shortness of breath, and as the disease progresses, will become progressively limited in the ability to exercise.

Chronic Bronchitis is a chronic disease of the airways that results in production of excess secretions and chronic infection.

Both chronic bronchitis and emphysema reduce the ability of the patient to safely recover from surgical or radiation therapy. Patients with severe COPD are unable to cough effectively and clear secretions. The result can be steadily worsening difficulty in breathing during the post-operative period, culminating in respiratory failure and sometimes death.

Damage to the lungs begins early on in smokers. Forced Expiratory Volume in one second (FEV1) is a commonly used measure of lung function. In adolescent smokers FEV1 is reduced by an average of 390 ml in boys and 360 ml in girls (i.e. approximately 10-15% reduction). Reduction in FEV1 occurs normally with aging, but is faster in smokers by 15ml./year. By middle age 18% of male smokers have FEV1 reduced more than 2 standard deviations. The deficits are larger if there are other causes of obstruction such as asthma "the horse racing effect". Kerstjens et. al.. Decline in FEV1 by age and smoking status: facts figures and fallacies. Thorax 1997;52:820-7.

At least 75% of all cases of emphysema occur in cigarette smokers.

Emphysema is approximately ten times more common than lung cancer with an estimated 1,600,000 patients with the disease in the U.S.

Many patients with lung cancer also have emphysema.

Pulmonary function is tested by measuring the levels of oxygen and carbon dioxide in arterial blood (ABGs) and spirometry, i.e.measuring the amount of air that the patient can move in and out of the lungs during various maneuvers (PFTs).

These tests, combined with the information from history and physical examination, will usually allow the surgeon to predict, reasonably accurately, what the risk of surgery is, and whether the patient will have significant disability after surgery.

Important new information has been derived from The Lung Health Study as reported in Pulmonary Perspectives June 1996;13:1-3. which clearly demonstrated that early identification and intervention can prevent chronic lung disease. Patients who had pulmonary function testing and special smoking smoking cessation instructions had a higher rate of abstinence after 5 years (22%) than did those who received standard medical care (5%). Sustained quitters had much less deterioration in Forced Vital Capacity in 1 Second (FEV1) over the five years of the study. Other important facts found in the study. More than 100 of the 5887 patients enrolled developed lung cancer. Lung cancer caused more deaths in the study than all other causes combined ! This study reinforces the previously known risk of lung cancer in smokers but offers encouragement that the relentless progressive lung damage caused by emphysema (COPD) can be prevented by smoking cessation. It also demonstrated that effective intervention can increase the chance of a patient's kicking the cigarette habit.

My esteemed colleague Brian Tiep MD ACCP has crafted an excellent review of COPD information available in the WWW at the American Thoracic Society web page Chronic Obstructive Pulmonary Disease

There is a great resource for information on chronic obstructive lung disease and emphysema (COPD) on the web on the web site of the American Thoracic Society sent to me by Dr. Brien Tiep MD. Standards in the Diagnosis and Management of Patients with COPD

Home oxygen therapy, required mainly by emphysema patients who's disease is caused in most cases by cigarette smoking, costs $1.1 billion in direct costs to Medicare. The total cost to society of course is much higher.O'Donohue WJ, Plummer AL. Chest 1995;107:301-2. U.S. mortality data show that Chronic Obstructive Lung Disease is a much worse problem than previously recognized. Between 1979-93 2,554,959 people (8.2% of all deaths) had COPD listed on their death certificates. Only 1,106,614 had COPD as the direct cause of death. This means that on top of approximately 80-90,000 deaths/year, COPD also contributes to another 120,000. The authors note that information on death certificates usually underestimates the true incidence of a disease. Most frightening, the number of deaths in women from this cause rose by 128% during this 14 year period. Mannino DM et. al. Obstructive lung disease deaths in the United States from 1979 through 1993: An analysis using multiple-cause mortality data. Am J Respir Crit Care Med 1997;156:814-8.

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Some good places to go for more information on chronic bronchitis and emphysema include the following:

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Clair Oh, a reporter on the Washington Post describes her family experience with COPD .

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