Hidden and obvious swelling
Edema occurs with many kidney diseases,especially such as acute and chronic glomerulonephritis, nephropathy of pregnant women, amyloidosis of the kidneys, diabetic glomerulosclerosis. Edema is almost constant and the most vivid clinical manifestation of nephrotic syndrome. The expression of edematous syndrome can be different. In some cases, swelling is insignificant in the form of pastose in the face and lower legs, in others it is mild and easily discernible on examination of the patient, in the third - with severe, massive, often anasarka with ascites, hydrothorax, hydropericardium, which is most characteristic of nephrotic syndrome . Sometimes 15-20 kg of fluid can be retained in the body, but not more than 10-12% of body weight (EM Tareyev, 1958).
Unlike cardiac edema, which usuallylocated on the sheltered places (feet and legs, in the region of the waist), kidney swelling is widespread everywhere - on the face, trunk, limbs. In some cases, they are formed quickly (for several hours or days), in others - slowly, gradually, increasing for many days. They can be dense to the touch or, conversely, soft, doughy, when when pressing a finger for a long time remains a hole, for example, with nephrotic edema. In some patients, visible swelling may be absent, in spite of the apparent fluid retention in the body, determined by the decrease in the amount of urine (oliguria).
The mechanism of the onset of edematous syndrome:
decreased glomerular filtration;
water retention due to sodium retention - an increase in the volume of circulating blood;
decrease in oncotic pressure.
Decrease in oncotic pressure of plasma atlarge losses of protein leads to accumulation of fluid in peripheral tissues and cavities. Along with this, hypovolemia activates the sympathetic nervous and renin-angiotensin-aldosterone systems, which increase the reabsorption of sodium with tubules followed by a delay in water in the body. So massive swelling, characteristic of nephrotic syndrome, is formed.
In the body of an adult person canlinger up to 2-3 and even up to 6-7 liters of fluid without the appearance of visible on the eyes and palpable swelling (AY Yaroshevsky, BB Bondarenko, 1972). This is the so-called hidden swelling. To confirm and determine the degree of fluid retention in the body, it is necessary to weigh the patient daily and determine the daily water balance, i.e. to measure the amount of liquids drunk during the day (taking into account liquid dishes, compotes, etc.) and isolated urine (diuresis daily).
When the fluid is delayed even before the appearance of visibleedema not only increases the body weight (up to 0.5-1 kg per day), but also a decrease in the amount of urine compared to the volume of the fluid drunk. When the concealed edemas converge spontaneously or under the action of diuretics, body weight decreases rapidly due to loss of fluid, manifesting a marked increase in diuresis with excess of urine over the amount of liquid drunk during the day.
Puffiness of body tissues, orthe tendency to the formation of edema, can be determined by a blister sample, or a McClure-Aldrich sample. Intradermically, 0.2 ml of isotonic sodium chloride solution is injected into the area of the anterior surface of the forearm with a thin needle using a syringe with small divisions. With normal hydrophilicity of tissues, absence of delay in the body of fluid and edema, resorption of the formed blister (blister) occurs slowly, for 60 min, not less (EM Tareyev, 1958). In patients with increased hydrophilicity of tissues, and consequently, with a tendency to fluid retention and formation of edema, blister dissolving occurs more quickly - in 40-30-10 minutes (depending on the degree of hydrophilicity of the tissues); with a pronounced edematous tissue readiness, the blister is not formed at all, since the isotonic solution of sodium chloride is immediately absorbed.
With the mechanism of formation of edematous syndrome with nephrotic syndrome, a state that requires intensive care for the sick can develop, a hypovolemic crisis.
Despite the fact that all patients suffer from edema,hypovolemic crisis is not found in all. As a rule, it happens in patients at the time of acute relapse of the NA. This condition is characterized by pronounced oliguria, orthostatic hypotension, tachycardia and a weak pulse. There is an increase in hematocrit. Subjectively, patients complain of nausea, pain in the abdomen, they are disturbed by vomiting. Intravenous administration of plasma (20 ml / kg) or high-concentration albumin (20%, 1 g / kg body weight) for 4 hours, followed by jet administration of furosemide (1-2 mg / kg), significantly helps the patient. It should be remembered, however, about the possibility of developing pulmonary edema with the use of albumin.
Diuretics in the fight against swellingshould be given extremely cautiously, since patients with UA are in a state of more or less pronounced hypovolemia. Therefore, in order to obtain an effective response to saluretics, it is first necessary to restore the circulating blood volume deficit with albumin or plasma substitutes. For this purpose, a 20-25% solution of albumin is administered intravenously at a dose of 0.5-1 g / kg for 30-60 minutes, followed by 1-2 mg / kg and above for 60-90 minutes.
With refractory swelling can be usedcombination of loop diuretics with thiazides, spironolactone. Combinations of diuretics act unidirectionally, blocking the reabsorption of sodium in various parts of the nephron.