Pulmonary edema is a diffuse extravascular accumulation of fluid in the pulmonary tissues and air spaces. Most commonly, it represents the projection of cardiac disease processes, such as atherosclerosis, hypertension, or valvular disease. The condition is usually a direct consequence of left ventricular failure. Pulmonary edema can occur as a chronic condition, or it can develop quickly. Pulmonary edema is considered a medical emergency.
When the alveoli fill with fluid instead of air, preventing oxygen from being absorbed into the bloodstream, more blood is added to the pulmonary circulation than can be adequately removed. In addition to the cardiac problems already mentioned, pulmonary edema may also be the result of lung infections, living at high altitudes, smoking, certain toxin exposure, pneumonia, and acute respiratory diseases.
Signs and Symptoms
The onset of pulmonary edema frequently occurs at night, after the person has been lying down for a while. In the more acute form, clients exhibit dyspnea, coughing, and difficulty breathing unless sitting erect or standing (orthopnea). Tachycardia, tachypnea, diffuse rales, and frothy bloody sputum also may occur. A decrease in blood pressure; a fine, barely perceptible thready pulse; and cold, clammy skin occur as cardiac output fails. These symptoms of cardiac output failure constitute a medical emergency
Clinical features indicate the diagnosis. Arterial blood gas analyses and chest x-rays are useful in diagnosing this condition. Electrocardiogram, regular echocardiogram, and transesophageal echocardiogram are often performed. Pulmonary artery catheterization may be used to confirm left ventricular failure.
Oxygen is typically administered along with bronchodilators and diuretics. Digitalis may be administered to stimulate heart action, and medication may also be prescribed to relieve anxiety. Aspirin and blood pressure medications may be given. Fluid intake may be limited, and mechanical ventilation may be necessary.
No significant complementary therapy is indicated.
Clients will be anxious, so reassure them as much as possible. Using a calm voice, explain all procedures. Provide emotional support to all family members. Remind clients to report any weight gain of even 2 to 3 lb, to rest periodically during the day, and to avoid drinking alcohol.
Edema in the legs, abdomen, or pleural membranes is serious. Acute pulmonary edema can be fatal. The outcome depends on the condition of the heart and lungs before the edema develops. Drug-induced pulmonary edema can be a cause of death in individuals who abuse narcotics.
There is no known prevention, but certain steps can reduce risk. They include lowering blood pressure and cholesterol, eating a healthy diet, exercising regularly, not smoking, managing stress, and making certain there is sufficient folic acid in the diet.