Pulmonary edema can be manifested by sudden onset of severe breathlessness, rattling breath and coughing attacks.
Causes: What causes pulmonary edema?
The cause of pulmonary edema is either an increase in pressure within the pulmonary vessels or an increase in the permeability of the pulmonary vascular walls. Sometimes combinations of both causes are present.
Cardiac Pulmonary Edema
When the pressure within the vessels increases, it is mostly due to heart disease. One speaks of a cardiac pulmonary edema. For example, a heart attack, an inflammation of the heart muscle, a disease of the coronary vessels or too high a blood pressure in pre-existing heart failure underlying.
These diseases weaken the left ventricle. As a result, they can not pump the oxygen-rich blood provided by the lungs fast enough into the body. The blood builds up in the pulmonary vein. The congestion increases the pressure on the blood vessels. As a result, blood fluid escapes from the vessels and is forced into the lung tissue. The walls of the blood vessels work like filters and allow only the liquid to pass.
The remaining blood components, such as red blood cells or other cells, are held back. The fluid first accumulates in the interstices of the cells and can then penetrate into the interior of the alveoli. As a result, they can perform their task increasingly poorly and oxygen uptake is becoming increasingly difficult.
Altitude Pulmonary Edema
A special feature of the pulmonary edema was the so-called high-altitude edema. It is triggered in mountain climbing at high altitude in the first two to three days by a combination of oxygen deficiency and low air pressure. The vessels contract and cause an increase in blood pressure, which overloads the left ventricle and creates a backlog.
Non-cardiac pulmonary edema
In non-cardiac pulmonary edema, the most common cause is damage to the membranes of the fine pulmonary capillaries. As a result, they lose part of their barrier function; blood fluid, together with smaller cell components, can penetrate into the tissue of the lung. The more effective the lymphatic vessels can initially remove the excess fluid, the slower the development of symptoms.
In most cases, ARDS (Acute Respiratory Distress Syndrome) is the cause of membrane damage. In this case, the lungs react to massive damage, for example from infections with viruses, inhalation of toxic gases, medication, severe burns, serious cardiovascular shock or blood poisoning. Rarely, pulmonary embolism, overdose in anesthesia, or stroke can increase membrane permeability.
“Another cause is damage to the liver and kidneys, which leads to a drop in albumin in the blood – a specific blood protein,” says Köhler. Due to the lack of protein, the blood fluid cannot be kept in the necessary amount in the blood vessels and thus reaches the cell gap to the outside.
For diagnosis, the doctor asks questions about the underlying and concomitant diseases of the heart, lungs and other organs. When listening to the lungs with the stethoscope rattling noises fall on, which sometimes are already audible with the naked ear. An x-ray examination can be used to determine whether water is actually in the lungs. Important indications for pulmonary edema include accelerated breathing, increased heart rate and blueing of the skin and mucous membranes. An ECG, echocardiography and other examinations target the underlying cause.
Therapy: How is pulmonary edema treated?
Pulmonary edema is a serious, potentially life-threatening condition requiring intensive medical treatment. Patients should be transported to the hospital as soon as possible. As a first measure, an upper body and lower legs are helpful. As a result, the blood flows back to the heart slower, so this is relieved.
Breathing can be assisted by the delivery of oxygen via a nasogastric tube or a mask. In an advanced stage, positive pressure ventilation, in some cases artificial respiration is necessary. Most patients are supplied with painkillers and tranquilizers.
Dehydrating medications (diuretics) ensure that the water drains from the tissue. This not only improves the oxygen exchange at the alveoli but also relieves the blood pressure by reducing the volume of fluid and thus reduces the burden on the heart. Drugs that dilate the vessels lower the pressure on the heart, improving the oxygen supply.
All other measures depend on the underlying cause. In case of height elevation edema, sufferers should descend as soon as possible. In addition, oxygen delivery, vasodilating drugs, and positive pressure ventilation may help.