Definition – What is pulmonary edema?
Pulmonary edema is, quite simply put, an accumulation of fluid in the lungs. The causes are quite different. However, the most common are two different types of pulmonary edema: the interstitial type, where the fluid is located in the lung tissue, and the intra-alveolar type, where the fluid is located in the lung cavities, i.e. the small air sacs in the lungs.
- Infection of the lungs,
- Heart failure
- As well as the associated renal insufficiency.
Causes
There are numerous causes for the development of pulmonary edema. The most important ones are listed and explained below. A very rough distinction is made between cardiogenic and non-cardiogenic pulmonary edema.
In so-called “cardiogenic pulmonary edema”, the cause is cardiac insufficiency. The mechanism is as follows: Chronic pressure on the left ventricle. The chamber can initially compensate for this pressure load by thickening the heart muscle.
At some point, however, the load becomes so great that the ventricle also dilates, i.e. becomes worn out to a certain extent. At that point at the latest, it can no longer work properly and thus no longer transports enough blood through the circulation. As a result, the blood accumulates in the sections of the vascular system located in front of the left heart.
This is the lung. When blood accumulates back, high pressure is created in the vascular system of the lung, which forces fluid out of the lung capillaries and into the lung tissue.
- High blood pressure,
- A narrowing of the aortic valve
- Or also due to genetic defects
The group of non-cardiogenic pulmonary edema includes all pulmonary edemas whose cause is not cardiac.
The following causes belong to this group: Infections If the infection with bacteria or viruses leads to pneumonia, the entire lung tissue is irritated. If the lung capillaries are damaged, they leak. This creates holes in the vessels, so to speak, through which fluid can enter the tissue.
On the other hand, pulmonary edema can also cause an infection. The accumulation of fluid in tissue is the perfect breeding ground for germs, so that they can multiply particularly quickly and cause pneumonia. In a sense, this is a vicious circle, and for this reason, pulmonary edema should be treated as quickly and effectively as possible.
Toxic substances can also cause pulmonary edema if they are toxic, i.e. “poisonous” to the lungs. These substances include certain gases, such as flue gas or chlorine gas, but excessive oxygenation can also cause toxic irritation of the lung tissue. On the other hand, certain drugs can also be the cause: various antibiotics and chemotherapeutic agents have lung-damaging properties.
By aspiration Aspiration is the process of swallowing liquids or food into the lungs. This often occurs when the doctor has to intubate a patient who is not fasting, i.e. who has recently eaten. However, even in the case of a drowning trauma involving fresh or salt water, fluid that does not belong in the lungs can get into the lungs.
The lung tissue reacts very irritably to this and pulmonary edema quickly develops. Oncogene pulmonary edema Oncogene pulmonary edema is an accumulation of fluid in the lungs caused by a protein deficiency. For the liquid components of the blood to remain in the vessels, a certain amount of protein must be present in the blood.
These “attract” water, so to speak. If the blood contains too little protein, the water escapes the vessels and quickly reaches the lung tissue, but theoretically also all other tissues (leg edema, ascites, etc.). There are two main causes of protein deficiency in the blood: The first is malnutrition.
Malnutrition also causes a generalized protein deficiency in all tissues, which is also called “hunger edema”. The second cause is liver failure. The liver is our central metabolic organ.
In addition to numerous other tasks, it also produces the various proteins that circulate in the blood: These include albumin, the central transport protein of the blood, the coagulation factors and so-called “acute phase proteins“, which are mainly released during inflammation.If the liver is damaged due to hepatitis, chronic alcohol abuse or toxicity, it no longer performs its normal tasks, such as the production of proteins. A protein deficiency develops here as well, and fluid escapes from the vascular system. High-altitude pulmonary edema High-altitude pulmonary edema is caused by staying in high mountains, especially during rapid ascents.
At over 3000m above sea level, the oxygen partial pressure of the air is significantly reduced. This means that when you breathe in, you inhale much less oxygen than is the case at sea level. Of course, oxygen for normal body functions is missing.
The body tries to compensate for this by increasing the breathing frequency. However, the insufficient oxygen saturation also causes the pulmonary vessels to contract. This leads to increased pressure in the vessels, causing the capillaries to leak and allow fluid to escape into the tissue.
To avoid this side effect of staying at altitude, it is recommended to ascend slowly. This allows the body to get used to the new composition of the air and to adapt slowly so that pulmonary edema does not occur. Pulmonary edema after pleural puncture In the course of a pleural effusion, i.e. an accumulation of fluid in the lung skin, it may be necessary to aspirate this fluid from the lung skin by means of a puncture.
If too much fluid is aspirated, pulmonary edema can develop as a reaction to the changing pressure conditions, which also affect the lungs. The negative pressure draws the blood from the vessels into the alveoli, so to speak. For this reason, it is recommended not to remove more than 1200ml of fluid at once.
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