What disease causes the walls of the alveoli to deteriorate and lose their elasticity?

What Is Emphysema?

Emphysema is a lung disease that results from destruction of lung tissue and irreversible enlargement of the alveoli (air sacs) that deliver oxygen to and remove carbon dioxide from the blood. As the walls of the alveoli become progressively enlarged, they lose elasticity and have a reduced ability to force air out of the lungs during expiration. As a result, the affected air sacs cannot properly fill up with fresh air during inspiration, and the exchange of oxygen and carbon dioxide between the alveoli and the blood becomes impaired. This leads to the shortness of breath that characterizes emphysema.

Along with chronic bronchitis, emphysema is one of the primary lung disorders that constitutes chronic obstructive pulmonary disease, or COPD

The onset of emphysema is gradual, with symptoms typically developing after age 50; however, irreversible lung damage may occur long before symptoms become severe enough to warrant medical attention. Such damage is initiated by smoking or other lung irritants, which lead to the destruction of lung tissue.

The prognosis for patients who have emphysema varies, depending on the severity of the condition and whether or not the patient continues to smoke. Although the disease is progressive and irreversible, patients who stop smoking and receive oxygen therapy generally have a longer life expectancy.

Who Gets Emphysema?

According to the American Lung Association, more than 3.1 million people in the United States have been diagnosed with emphysema. Emphysema and other types of COPD are the fourth leading cause for death in the United States. The condition occurs slightly more often in men (about 52 percent of cases) than women; however, the mortality rate is higher in women. Emphysema is more common in Caucasians than African Americans.

More than 90 percent of patients who have emphysema are over the age of 45 at the time of diagnosis. The disease is most common between the ages of 60 and 80.

Approximately 100,000 people in the United States have an inherited form of the condition called alpha-1 antitrypsin deficiency emphysema or familial emphysema. This disease, which is more common in people of northern European descent, often causes symptoms between the ages of 32 and 40.

Symptoms

• Shortness of breath.

• Wheezing.

• Cough (wet or dry).

• Fatigue.

• Weight loss.

• Barrel-chested appearance.

• Cyanosis (bluish tint to the lips, fingertips, and skin; caused by low levels of oxygen [O2] in the blood).

• Edema (swelling; commonly in the feet and ankles).

• Headaches (especially upon waking in the morning as a result of low oxygen levels during sleep).

What If You Do Nothing?

If emphysema goes untreated, and especially is a patient continues to smoke, symptoms will worsen. In addition, emphysema can lead to a number of complications that include:

• Cor pulmonale (pulmonary hypertension and right-sided heart failure)

• Heart failure

• Pneumonia and other lung infections

• Pneumothorax (collection of air within the membrane that surrounds the lungs [pleural space])

• Polycythemia (excess red blood cell production that occurs in response to low oxygen levels in the blood; can block small blood vessels)

• Respiratory failure

Causes/Risk Factors

• Smoking is the leading cause of emphysema. Up to 85 percent of emphysema cases develop in longtime cigarette smokers.

• Prolonged exposure to lung irritants, such as industrial fumes and dust, and living in areas with poor air quality are other factors associated with the development of emphysema.

• Emphysema may also occur as a result of an inherited deficiency of alpha-1-antitrypsin (AAT). This enzyme normally hinders tissue destruction in the lung. Rare individuals missing this enzyme can develop emphysema at an early age, even if they don’t smoke.

Diagnosis

To diagnose emphysema, the doctor takes a complete patient and family medical history and performs a physical examination. If these suggest a diagnosis of emphysema, diagnostic tests may be performed.

Tests used to diagnose emphysema include the following:

• Blood tests (e.g., complete blood cell count [CBC], arterial blood gas [ABG]). Blood tests can be used to rule out other conditions and can identify individuals with alpha-1-antitrypsin deficiency. Arterial blood gas measures levels of oxygen and carbon dioxide in the blood and can be used to determine if oxygen therapy is needed.

• Imaging tests (e.g., chest x-ray, computed tomography [CT scan]). A chest x-ray or CT scan will likely be required to demonstrate the lung damage that distinguishes emphysema from other forms of lung disease.

• Oximetry (noninvasive method to measure levels of oxygen in the blood). An electronic device called a pulse oximeter is attached to a part of the body (e.g., finger tip, ear lobe, forehead) and used to measure oxygen (O2) levels in the blood.

• Pulmonary function tests (e.g., peak flow, spirometry). Pulmonary function tests (PFTs) are used to measure air flow within the lungs and evaluate lung function. Lung volume tests also may be performed to measure lung capacity and function.

Emphysema is an irreversible condition and the goals of treatment are to reduce symptoms and to slow progression of the disease. The most important step is to quit smoking. Smoking cessation can slow the decline of lung function considerably.

Treatment for emphysema may include the following:

• Medications. There are a number of different types of medications that can be used to treat emphysema. Some types are inhaled (e.g., through an inhaler or a nebulizer), and others are taken orally (e.g., in pill form).

• Inhalers and nebulizers deliver medication directly into the lungs, which can result in fewer side effects; however, if these devices are used incorrectly, the medication may be ineffective. A spacer device is a tube that can be used with an inhaler to help patients take the medication correctly.

• Bronchodilators (e.g., anticholinergics, beta agonists, theophylline) can be used to treat acute exacerbations (called short-acting medications) or to prevent symptoms from worsening (called long-acting medications). Antibiotics (e.g., azithromycin, doxycycline) often are used to treat infections that cause acute exacerbations; anti-inflammatory drugs (e.g., steroids [prednisone]) can be used to reduce lung inflammation.

• Patients who have familial emphysema (alpha-1 antitrypsin deficiency emphysema) may be treated with an alpha-1 protease inhibitor (e.g., Aralast, Prolastin), which usually is administered intravenously (i.e., through a vein). Prior to infusion, patients may be given other medications to reduce the risk for an allergic reaction.

• Oxygen therapy. Oxygen therapy often is necessary to treat advanced cases of emphysema. In most cases, oxygen (O2) is delivered through a small tube (called a nasal cannula) from an oxygen tank to the patient's nose. Some patients require extra oxygen while walking, exercising, or sleeping, and others require it continuously. Portable oxygen units also are available.

• Pulmonary rehabilitation. This treatment, performed by a multidisciplinary team including respiratory therapists, physical and occupational therapists, other healthcare professionals, strives to help the patient become more physically active, become more educated about their disease and treatment options, and generally reduce disability from the disease. Respiratory therapists may help educate the patient and make sure medical equipment is functioning properly, adjust settings as instructed by a physician, and instruct patients in the correct use of the equipment. Physical and occupational therapists assist patients with special exercises that train muscles used for breathing and nutritionists may help patients with developing a plan on eating appropriately and maintaining a healthy weight.

• Surgery. Surgery may be used to treat emphysema in a select group of patients. Types of surgery include lung reduction surgery (involves removing damaged areas of lung tissue to allow healthy tissue to function more effectively) and lung transplant surgery (only considered in select patients with end-stage disease). Patients who have advanced disease are at increased risk for surgical complications, including death.

Prevention

Avoiding exposure to cigarette smoke is the most effective way to prevent developing emphysema. And while nearly all smokers suffer some lung damage, quitting smoking can prevent further lung deterioration.

Maintaining a healthy lifestyle (e.g., exercising regularly, eating properly), avoiding exposure to air pollution and second-hand smoke, and receiving prompt medical treatment for respiratory infections also can help prevent emphysema.

When To Call Your Doctor

Call a doctor if you experienced worsening of shortness of breath or if symptoms of emphysema become more severe.

Reviewed by Allen J. Blaivas, D.O., Division of Pulmonary, Critical Care, and Sleep Medicine, VA New Jersey Health Care System, Clinical Assistant Professor, Rutgers New Jersey Medical School, East Orange, NJ. Review provided by VeriMed Healthcare Network.