Pulmonary Edema - Page Four

When To Seek Medical Advice

Acute pulmonary edema is life-threatening. Get emergency assistance if you have any of the following acute signs and symptoms:

Trouble breathing or a feeling of suffocating (dyspnea)
A bubbly, wheezing or gasping sound when you breathe
Pink, frothy sputum when you cough
Profuse sweating
Lightheadedness
A blue or gray tone to your skin
A severe drop in blood pressure

Acute pulmonary edema is likely to be incapacitating, so don't attempt to drive yourself to the hospital. Instead, dial 911 or emergency medical care and wait for help.

Screening and Diagnosis

Because pulmonary edema requires prompt treatment, you'll initially be diagnosed on the basis of your symptoms and a physical exam. You may also have blood drawn — usually from an artery in your wrist — so that it can be checked for the amount of oxygen and carbon dioxide it contains (arterial blood gas concentrations).

Once your condition is more stable, your doctor will ask about your medical history, especially whether you have ever had cardiovascular or lung disease. You will also likely have a chest X-ray, which can help support a diagnosis of pulmonary edema. And you may have further tests to determine why you developed fluid in your lungs. These tests may include:

Electrocardiography (ECG). This noninvasive test can reveal a wide range of information about your heart. During an ECG, patches attached to your skin receive electrical impulses from your heart. These are recorded in the form of waves on graph paper or a monitor. The wave patterns show your heart rate and rhythm, and whether areas of your heart show diminished blood flow.

Echocardiography (diagnostic cardiac ultrasound exam). Another noninvasive test, echocardiography uses a wand-shaped device called a transducer to generate high-frequency sound waves that are reflected from the tissues of the heart. The sound waves are then sent to a machine that uses them to compose images of your heart on a monitor. The test can help diagnose a number of heart problems, including valve problems, abnormal motions of the ventricular walls, fluid around the heart (pericardial effusion) and congenital heart defects. It also accurately measures the amount of blood your left ventricle ejects with each heartbeat (ejection fraction, or EF). The ventricles don't empty all their blood with each beat, but in most cases the EF should be greater than 50 percent. When the left ventricle begins to fail, this number falls. Although a low EF often indicates a cardiac cause for pulmonary edema, it's possible to have cardiac pulmonary edema with a normal EF.

Transesophageal echocardiography (TEE). In a traditional cardiac ultrasound exam, the transducer remains outside your body on the chest wall. But in TEE, a soft, flexible tube with a special transducer tip is inserted through your mouth and into your esophagus — the passage leading to your stomach. This provides a clearer view of your heart and central pulmonary arteries than does traditional echocardiography. You'll be given a sedative to make you more comfortable and prevent gagging. You may have a sore throat for a few days after the procedure, and there's a slight risk of perforation or bleeding from the esophagus.

Cardiac catheterization. If other tests don't reveal the reason for your pulmonary edema, your doctor may suggest a procedure to measure the pressure in your lung capillaries (wedge pressure). During this test, a small, balloon-tipped catheter is inserted through a vein in your leg or arm into a pulmonary artery. The catheter has two openings connected to pressure transducers. The balloon is inflated and then deflated, giving pressure readings.

Complications

When not treated, acute pulmonary edema can be fatal. In some instances it may be fatal even if you receive treatment. The outcome depends in part on the condition of your heart and lungs before you developed edema and on the amount of fluid in your lungs. Drug-induced pulmonary edema is a frequent cause of death in people who abuse narcotics.

Treatment

Administering oxygen is the first step in treating any kind of pulmonary edema. You usually receive oxygen through a face mask or nasal cannula — a flexible plastic tube with two openings that deliver oxygen to each nostril. This should ease some of your symptoms. Sometimes it may be necessary to assist your breathing with a machine.

Depending on your condition and the reason for your pulmonary edema, you may also receive one or more of the following medications:

Furosemide (Lasix). This diuretic works quickly to expel excess fluid from your body in cases of cardiac pulmonary edema.

Morphine (Astramorph, Roxanol). This narcotic, for years a mainstay in treating cardiac pulmonary edema, may be used to relieve shortness of breath and associated anxiety. But some doctors now believe that the risks of morphine may outweigh the benefits and are more apt to use other, more effective, drugs.

Afterloaders. These are drugs that dilate the peripheral vessels and take a pressure load off the left ventricle.

Aspirin. Your doctor may recommend starting aspirin therapy if you're not already taking it. Aspirin helps thin the blood so that it moves through your small blood vessels more easily.
Blood pressure medications. If you have high blood pressure when you develop pulmonary edema, you'll be given medications to control it. On the other hand, if your blood pressure is too low, you're likely to be given drugs to raise it.

Treating high-altitude pulmonary edema (HAPE). If you're climbing or traveling at high altitudes and experience mild symptoms of HAPE, descending a few thousand feet should relieve your symptoms. Oxygen also is helpful. When symptoms are more severe, you'll likely need help in your descent. A helicopter rescue may be necessary for the most serious cases.

Sometimes, however, immediate rescue isn't possible. With this in mind, researchers have devised several experimental therapies. In one, the distressed climber is placed in an airtight bag known as a hyperbaric bag, which is then pumped with air, simulating the air pressure at a lower altitude. A night's sleep in the bag seems to relieve symptoms — at least temporarily.

Some climbers take the prescription medication acetazolamide (Diamox) to prevent symptoms of HAPE. Diamox can occasionally have side effects — including tingling or burning in the hands, feet and mouth, confusion, diarrhea, nausea, and thirst — and must be started three days before your ascent.

Mayo Clinic

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