Pulmonary edema is a pathophysiological process in which the liquid part of the blood as a result of stagnation in the vessels of the small( pulmonary) circulatory system begins to enter the interstitial tissue or directly into the respiratory alveoli.
The appearance of pulmonary edema means the development of acute left ventricular failure, in which the left ventricle of the heart is not able to provide adequate discharge of blood into the vessels of the great circle of blood circulation, and the blood "stagnates" in the pulmonary vessels under increasing pressure.
Any person may have pulmonary edema, so it is important to know everything about his clinic( symptoms), causes and tactics of emergency care in this condition - you can save someone's life.
Pathophysiology of the process
With congestion of blood in the capillaries of the lungsspecial changes begin to occur that lead to an increase in the permeability of the membrane created by the cells of the alveolar and vascular walls. Because of the accumulation of a large amount of fluid in the capillaries, the hydrostatic blood pressure increases, while the oncotic pressure decreases.
Pathogenesis: what causes
The most common causes are acute and chronic decompensated cardiac muscle diseases .These include:
- Myocardial infarction, accompanied by a large area of tissue damage or complete rupture of the heart wall.
- Various kinds of cardiac arrhythmias( suprasystolic or ventricular extrasystoles, bradycardia, blockages of the sinoatrial or atrioventricular nodes of the conducting system).
- Cardiac defects( mitral and aortic stenosis - constriction - or insufficiency).
- An increase in the size of the right chambers of the heart is a "pulmonary" heart.
- Acute myocarditis.
- Cardiomyopathy with cardiac muscle hypertrophy.
- Hypertensive crisis with a sharp increase in blood pressure.
- Cardiac tamponade.
- Mechanical trauma of the heart.
- Thromboembolism of the pulmonary artery( PE).
The causes of edema can also include conditions such as anemia, symptomatic arterial hypertension as a manifestation of glomerulonephritis, thyrotoxicosis with increased release of thyroid hormones into the blood, toxic effects on the alveolar membrane. To the edema can cause a trauma of the chest, pneumothorax, pneumonia, pleurisy, cirrhosis.
Classification: Species and stages
As mentioned above, edema can be either interstitial or alveolar .In fact, these two species are successively alternating stages of the general pathophysiological process.
Along with the above-described pathophysiological , the etiological classification :
- Cardiogenic pulmonary edema on a background of low or high release of blood by the heart muscle, that is, developing due to changes in the heart.
- Non-cardiogenic pulmonary edema, whose cause lies in the violation of other organs and systems( toxic, inflammatory, allergic, as a result of the introduction of significant amounts of parenteral solutions into the body).
How dangerous is
Pulmonary edema is a deadly pathophysiological process that complicates the course of a number of diseases of other human organs and requires the provision of emergency medical care.
Its is a high hazard due to oxygen deficiency of the body due to disruption of normal gas transport through the alveolar-capillary membrane.
Because of this , all organs and tissues do not receive sufficient amounts of oxygen from and can not remove carbon dioxide by entering into a state of ischemia. The first target organs are vital: the brain, heart, kidneys, adrenals, liver.
In addition, pulmonary edema can lead to changes in the very respiratory system , which include:
- Atelectasis of the lung( lung tissue falls due to partial or complete replacement of air masses in the fluid);
- Emphysema( an increase in the volume of terminal bronchioles and avlevale with breaks in the walls of the latter);
- Sclerotic changes in the lung parenchyma( substitution of normal lung tissue for connective tissue, incapable of gas exchange with blood);
- Pneumonia in the background of fluid stagnation.
Main symptoms
Patients with developed edema visually cyanotic( "cyanotic") .
Their breathing is noisy with bubbles rasping in the distance, the skin is wet and cold, position - orthopnea ( the person is forced to sit, often rests his hands in the chair to facilitate attempts to inhale).
In the breath involved not only the muscles that usually produce this act, but also the auxiliary musculature. This is manifested by a visually noticeable retraction of the intercostal spaces, supra- and subclavian pits, intensified abdominal muscles in accordance with the rapid rhythm of breathing.
Inspiratory( with shortness of breath) inspiratory dyspnea , accompanied by panic of the patient and fear of death.
Speaking of interstitial edema, it is worth noting the presence of predominantly wheezing on the background of other symptoms of , rarely heard small-bubble. In alveolar edema, wheezing is medium- and large-bubbly, loud, the patient coughs intensively with the departure of a large number of foamy pink( or bloody veins) sputum.
Which doctor will help
Most often, when an edema occurs, emergency medical care is provided by therapists, cardiologists, doctors who are part of the ambulance brigade, and anesthesiologists-resuscitators.
However, the physician of any specialty must know how to provide adequate care to a patient with pulmonary edema , because this situation can occur not only at home or hospital departments of the appropriate profile.
How to treat before and after the arrival of the "ambulance"
Even before the arrival of the team of doctors, the people surrounding the patient should help him to accept such an sitting position, at which his legs would be lowered down .This action will reduce the venous return to the right heart, which will "unload" a small circle of blood circulation, reducing preload on the heart muscle.
If there is an abundant amount of foamy sputum in the mouth of the patient, remove , clearing the airways. To do this, you can use your own fingers wrapped in tissue or a handkerchief. Be sure to open the ventilator and unbutton the clothes tightening the human body in order to maximize the oxygen influx at a given time.
With the arrival of doctors, the first aid is taken by them. The following measures are taken to stop pulmonary edema:
- Oxygen mixture( 100%) is supplied through a mask at a speed of 6 to 8 liters per minute. Often when swelling of the lungs, along with the mixture, so-called defoamers are introduced that can eliminate foamy sputum( a pair of ethyl alcohol with a usual concentration of 70%).
- Intravenous administration of morphine( 2 to 5 mg), which selectively affects the respiratory center in the medulla oblongata and reduces the flow of venous blood to the heart muscle, reducing pressure in the pulmonary circulation.
- The use of diuretics( diuretics), which will reduce the amount of circulating blood in the body and also reduce the venous load. Introduce drugs intravenously, usually use the drug "Lasix"( furosemide) in a dose of 40 to 100 mg.
- Intravenous jet infusion of prednisolone in a dose of 60-90 mg to relieve bronchospasm and reduce the fluid's exudation through the alveolar-capillary membrane.
- Cardiotonics( cardiac muscle stimulants), such as dopamine or dobutamine, are used to increase blood pressure.
- If the systolic blood pressure is more than 100 mm Hg.st., then intravenously drip an infusion of sodium nitroprusside( or nitroglycerin solution) to reduce afterload on the heart.
- Venous tourniquets are superimposed on three limbs( the fourth limb without a tourniquet is intended for intravenous infusion of drugs) to provide a smaller venous return.
Further treatment of
The following therapeutic measures are performed by in intensive care rooms of under strict control of hemodynamic parameters( blood pressure, heart rate), carbonation of blood gases, and the full value of the act of breathing.
If necessary, continue the introduction of cardiac and diuretics , given the presence of concomitant pathology in the patient. In cases where edema develops against the background of the infectious process, antibacterial agents are prescribed in accordance with their activity spectrum.
Mostly it develops against a background of acute or decompensated cardiac pathology. With the first symptoms, call the ambulance and begin to provide emergency measures.
