Pulmonary edema is a severe pathological condition in which fluid accumulates in spaces of lung tissue and alveoli outside the pulmonary blood vessels, which leads to impaired lung function. It occurs when, instead of air, the lungs begin to fill with serous fluid, which seeps out of the vessels. This may be due to excessive pressure in the blood vessels, a lack of protein in the blood, or an inability to retain fluid in the plasma.
Symptoms of cardiac asthma and pulmonary edema
Important is the correctness of the difference in symptoms of interstitial pulmonary edema and alveolar pulmonary edema, which stand out as two stages of the pathological process.
With interstitial pulmonary edema, which corresponds to the symptoms of cardiac asthma, fluid penetrates into all lung tissues. This significantly worsens the conditions for the exchange of oxygen and carbon dioxide between the air of the alveoli and blood, causes an increase in pulmonary, vascular and bronchial resistance. An attack of cardiac asthma (interstitial pulmonary edema) occurs most often at night or in the pre-day. The patient wakes up from a feeling of lack of air, takes a forced sitting position, is excited, feels fear. Appears shortness of breath, paroxysmal cough, cyanosis of the lips and nails, cooling of limbs, increased blood pressure, tachycardia. The duration of such an attack is from several minutes to several hours.
The subsequent development of the process, associated with the infiltration of fluid into the cavity of the alveoli, leads to alveolar edema of the lungs. The liquid begins to destroy the protective substance, which lining the alveoli from the inside, so that the alveoli stick together, are flooded with edematous fluid. At this stage, a stable protein foam forms, which begins to block the lumen of the bronchi, which leads to a decrease in the oxygen content in the blood and hypoxia. Alveolar edema of the lungs is characterized by a sharp respiratory insufficiency, severe dyspnea with distinct rales, cyanosis, skin moisture. On the lips appears a foam with a pinkish tinge due to the presence of elements of blood. Often the consciousness of the patients is confused, a coma may come.
Forms of pulmonary edema
Depending on the cause and origin, cardiogenic and non-cardiogenic pulmonary edema is isolated.
Cardiogenic pulmonary edema occurs in diseases of the heart and, as a rule, is acute. It can be a manifestation of left ventricular heart failure in myocardial infarction, cardiomyopathy, mitral insufficiency, aortic heart disease, as well as mitral stenosis and other diseases. In this case, the increased hydrostatic pressure in the pulmonary capillaries arises from the increase in pressure in the pulmonary vein, which causes edema.
Non-cardiogenic pulmonary edema is caused by increased vascular permeability of the lungs, which leads to the penetration of fluid into the pulmonary space. It can be associated with other clinical conditions:
There are also toxic pulmonary edema caused by the action of toxic substances on the lung tissue. Most often this condition is caused by poisoning with nitrogen oxides. During the process, several stages are distinguished: reflex, stage of hidden phenomena, clinical and reverse development. At the initial stage, there is a reflex reaction under the action of the substance: irritation of the mucous membranes, cough, and pain in the eyes. Further, the symptoms disappear, a latent phase occurs, lasting from two hours to a day. Then there are signs such as increased breathing, wet cough with wheezing, cyanosis, tachycardia. In mild cases and with timely treatment on the third day after poisoning, the condition is normalized.