Overhydration syndrome. Hypertonic, isotonic and hypotonic hyperhydration. Classification and symptoms of overhydration

Overhydration is an excess volume of water contained in the body or in its individual parts, a special form of disturbance of the water-salt balance of the body. Clinical manifestations of overhydration are swelling of body tissues, lungs, brain, excessive accumulation of fluid in the abdominal cavity - ascites. Some conditions during overhydration are critical to the patient's life.

The human body consists to a certain extent of water, the volume of which changes with age. Thus, the volume of water in the body of a newborn reaches 75%, while the body of an elderly person consists of only 55% water. Water in the human body is distributed among fluid sectors: the intracellular space contains about 60% of all water in the body, the remaining volume of water is distributed in the extracellular space - intercellular space, blood plasma, transcellular fluid (gastrointestinal tract, spinal canal, chambers of the eye, urinary ducts, adrenal tubules).

The body's water balance is maintained by a corresponding volume of incoming and outgoing fluid simultaneously. The daily norm of body fluid (2.5 l) comes from food (about 1 l), drinking (about 1.5 l), as well as in the form of oxidative fluid, which is formed during the oxidation of fats (about 0.3 - 0. 4 l). Fluid is removed from the body by evaporation (about 0.6 liters of fluid are excreted with sweat), through the kidneys (about 1.5 liters of fluid are excreted), with exhaled air (excretion of 0.4 liters of fluid per day), with feces (up to 0 .2 liters per day).

When the water balance is disturbed (overhydration), not only the volume of fluid contained in the body changes, but also the level of mineral content in the body changes. Excessive changes in the concentration of sodium, potassium and other minerals (electrolytes) during overhydration can lead to hyponatremia, hypokalemia, and a general electrolyte imbalance in the body.

Overhydration can occur in the body due to excess fluid intake or insufficient fluid excretion by the body. In some cases with diagnosed overhydration, both factors are present in the patient's body. Overhydration can develop both under the influence of external factors and as a result of impaired functioning of organs and diseases of the body.

Overhydration of the body: causes, types of dyshydria

The main causes of overhydration of the body are:

Excessive introduction of fluid into the body (water intoxication), which is characterized by a low salt content or their complete absence. Most often, this condition develops with repeated enteral administration of fluid into the body (excessive fluid intake in certain types of mental disorders, excessive introduction of water into the gastrointestinal tract during gastric lavage);
Decreased excretory function of the kidneys in renal failure;
Circulatory failure with the formation of edema;
Increased levels of ADH (antidiuretic hormone);
Congestive heart failure;
Cirrhosis of the liver.

The main types of overhydration of the body include:

Iso-osmolar hyperhydration of the body is an increase in the level of extracellular fluid with normal osmolarity. As a rule, this disorder is short-term in nature and is quickly eliminated by the body, provided that the systems that maintain its water balance are functioning normally;
Hypoosmolar hyperhydration - this type of hyperhydration develops simultaneously in the cellular and intercellular spaces, is characterized by a radical disruption of the acid-base and ionic balance, as well as the membrane potential of cellular structures;
Hyperosmolar hyperhydration is a form of hyperhydration that develops with the forced consumption of sea water as drinking water, in which a rapid increase in the concentration of electrolytes is observed.

Overhydration: symptoms of disorder

With overhydration, symptoms manifest themselves as follows:

Changes in circulating blood volume;
Increased blood pressure;
Heart rhythm disturbances;
Development of edema;
Impaired urine output (diuresis) – polyuria, anuria;
Intoxication of the body, vomiting, diarrhea;
Neuropsychiatric disorders - convulsions, apathy, impaired consciousness, lethargy.

In rare cases, with overhydration, redness of the skin, increased body temperature, sleep disturbances, and aversion to food are observed.

In case of overhydration, symptoms are subject to careful analysis to determine the form of dyshydria and prescribe appropriate treatment.

The main consequences of overhydration

The main consequences of overhydration include:

The development of tissue edema - pathological processes characterized by an increase in fluid content in the extravascular space of the body;
Pulmonary edema is a condition in which an increased level of fluid is diagnosed in the pulmonary interstitium;
Cerebral edema is a pathological process characterized by excessive accumulation of fluid in the cells of the brain and spinal cord;
Hyponatremia is one of the symptoms of overhydration, characterized by a decrease in the concentration of sodium ions in the blood plasma (level below 135 mmol/l);
Hypokalemia is a reduced level of potassium in the blood, provoked by a reduced amount of potassium entering the body, its migration into tissue cells, and its increased excretion;
Rapid weight gain.

Treatment of overhydration

The main risk group for developing overhydration of the body is patients with renal failure, heart failure, other kidney and liver diseases, as well as people exposed to increased physical activity, as well as those on a strict diet. In the treatment of overhydration, the causes of disturbances in the body's water balance play a key role.

Minor overhydration does not require additional drug correction. With the normal functioning of all systems, the body independently copes with excess fluid.

If overhydration is detected, the symptoms of which include headache, irritability, confusion, dizziness, patients are advised to limit fluid intake.

In severe cases of overhydration, drug treatment is used (diuretics are prescribed) aimed at restoring the body's water and electrolyte balance. In rare cases of overhydration, symptomatic treatment is prescribed. In complex forms of hyperhydration, patients are prescribed hemodialysis.

When following a diet, the body experiences a lack of minerals. Patients are advised to reduce their water intake, excess of which can lead to a decrease in electrolyte levels in the body. To avoid overhydration during increased physical activity and diets, complete exclusion of salt is not recommended. To replenish water and electrolyte balance, it is recommended to drink mineral water.

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Overhydration is a condition of the body characterized by excess water content in certain parts or throughout the body, and manifested by swelling in the legs, face, ascites, swelling of the brain and lungs. Overhydration is a form of disruption of water-salt metabolism.

This condition develops in the presence of heart failure, kidney failure, and liver cirrhosis.

Depending on the reasons, there are different types of overhydration.

Treatment of overhydration comes down to treatment of the underlying disease that causes this condition and dehydration therapy.

Causes of overhydration

This condition occurs when more water enters the body than it is able to remove. Its excess content leads to a decrease in sodium levels in the blood.

As a rule, excessive drinking of water does not lead to overhydration if the heart, kidneys, and pituitary gland are working normally.

Most often, the state of overhydration of the body occurs in people with impaired kidney function. Overhydration can occur with congestive heart failure, renal failure, liver cirrhosis, or excess production of antidiuretic hormone by the body.

If, with renal failure, a patient drinks more than three liters of water in an hour, uremic intoxication will develop and he may die from pulmonary edema, hypokalemia, or cerebral edema.

Therefore, people with the above diseases need to control the intake of water and salt into the body.

Classification and symptoms of overhydration

The following types of overhydration are distinguished:

extracellular – interstitial tissue or the entire extracellular space is subject to hydration. Associated with the retention of electrolytes in the body. The main clinical sign of extracellular hyperhydration is edema, which appears with an increase in hydration of more than 5-6 liters. The most dangerous are swelling of internal organs, abdominal edema;
cellular (intracellular edema) – associated with the accumulation of fluid in the cells. This type of overhydration of the body develops when an excessive volume of water or hypotonic solution is administered. Occurs in nephropathy, which is accompanied by an increase in the effective osmotic pressure of the interstitial fluid and the release of water from the cells. The main symptom of overhydration in this case is thirst and severe weight loss caused by the loss of large amounts of water;
hyperosmotic or hyperosmolar – associated with an increase in the osmotic pressure of fluids in the body. This condition is associated with the intake of large volumes of saline solutions into the body, especially in combination with the cessation or limitation of the excretion of water and salts by the kidneys, digestive tract, and skin. Symptoms of overhydration in this case are associated with extracellular overhydration (pulmonary edema, cardiac edema, increased cardiac output, circulating blood, blood pressure, central venous pressure, cerebral edema, hypoxia, respiratory failure, neuropsychiatric disorders, thirst) and intracellular hypohydration by the reason for the mobilization of intracellular fluid (thirst, hypoxia, neuropsychic disorders, general agitation, convulsions, anxiety, which are replaced by the progression of lethargy, decreased reflexes and loss of consciousness with the subsequent development of hyperosmotic coma);
hypoosmotic or hypoosmolar – associated with a decrease in the osmotic pressure of liquids. This type of overhydration occurs when the intake of water into the body prevails over its excretion (with repeated intake of excess volumes of liquids with a low salt content; prolonged consumption of salt-free foods; long-term pathological processes; peritoneal dialysis; infusions of large volumes of glucose). Symptoms of overhydration in this case are associated with a rapid increase in the volume of water in all sectors of the body and are manifested by progressive weight gain, the development and increase of edema, increasing weakness, deterioration of general condition, rapid fatigue, a feeling of weakness, and vomiting. Next, there is the development and intensification of neuropsychic disorders, confusion with subsequent loss of consciousness, convulsions and hypoosmotic coma, which in some cases ends in death;
general overhydration of the body or “water intoxication - when the entire body is exposed to overhydration. Occurs when an increased intake of water into the body is combined with insufficient excretion. Typically, this is hypoosmotic hyperhydration;
Normoosmotic or isotonic. It is characterized by a positive water balance with normal osmolality. There is no redistribution of fluid between the extra- and intracellular sectors. This type of hyperhydration is associated with the introduction of large volumes of isotonic solutions into the body, the development of pathologies accompanied by hypoproteinemia (liver failure, nephrotic syndrome), increased permeability of the vascular walls, and the development of blood and lymph circulation failure. Clinical manifestations of isotonic overhydration are: hypervolemia, increased cardiac output, blood volume, blood pressure, peripheral vascular resistance, and later the development of heart failure and edema.

Diagnosis of overhydration

When diagnosing this condition, it is important to establish the type of overhydration, since each of them requires appropriate therapy.

The goal of diagnosis is to determine whether overhydration or increased blood volume is occurring. When overhydration is present, excessive amounts of water are found around and within cells. As blood volume increases, excess sodium is observed and water is unable to move into the intracellular cavity. Distinguishing between increased blood volume and overhydration can be difficult because both processes can occur simultaneously.

To diagnose overhydration, the following are used: ultrasound of the kidneys, intravenous urography, cystography.

Treatment of overhydration

The choice of treatment method depends on the cause that caused the state of overhydration. But in any case, they try to limit the flow of fluid into the body. Drinking no more than one liter of fluid per day improves the patient's condition.

In case of severe overhydration, the patient is prescribed drug treatment, usually with the use of diuretics, which aims to restore water and electrolyte balance. Sometimes symptomatic therapy and hemodialysis are prescribed.

Overhydration is a condition of the body associated with the presence of a certain pathology, which leads to an imbalance in the water balance in the body. The goal of therapy for this condition is to treat the underlying disease and break the links in the pathogenesis of this condition.

Isotonic overhydration is characterized by an excess of water and solutes at normal plasma osmotic pressure (isotonic excess). With isotonic overhydration, it is mainly the extracellular space that suffers (especially interstitial tissue; see.

Edema diseases

Reasons (Fig. 40)

Rice. 40. Complex of causes of isotonic overhydration.

Excessive administration of saline solutions, usually parenterally, less often enterally, especially in cases of impaired renal function after surgery or injury to an adrenal tumor

Edema diseases

Heart disease with edema

Liver cirrhosis with ascites

Kidney diseases (eg, glomerulonephritis, nephrotic syndrome).

Symptoms (Fig. 41)

Rice. 41. Leading symptoms of isotonic overhydration

It manifests itself as a result of an increase in the extracellular space, especially its interstitial part

Edema formation

Clinically, edema appears only when a larger amount of fluid is retained; doughy edema of the skin; pulmonary edema

swelling of the gastric mucosa

rapid increase in body weight due to the accumulation of fluid ascites

Circulation

Circulatory parameters strongly depend on the underlying disease Pathophysiological data

Since plasma osmotic pressure fluctuates within normal limits, only the extracellular space, especially the interstitial space (“third space”) increases. The saturation of cells with water is normal.

Generalized edema formation can be caused by a number of factors, for example (Mertz):

Hemodynamic influence;

Decrease in colloid osmotic pressure,

Increased capillary permeability,

Hormonal imbalance

Any formation of general edema is accompanied mainly by sodium retention by the kidneys (the influence of aldosterone). In this case, hyperaldosteronism is detected only during the formation of edema, but not in its stable stage.

Secondary aldosteronism causes not only higher sodium reabsorption, but also increased potassium excretion, aggravated by diuretics (see Therapy). This may adversely affect the underlying disease (for example, with cardiac glucoside therapy, etc.).

In the presence of edema, although the body is oversaturated with water, this water is not used directly.

Diagnostics

The history and clinical picture allow us to draw a conclusion about organ disorders in which there is a tendency to water and sodium retention. Subsequent swelling indicates overhydration. Plasma osmotic pressure is within normal limits.

A reliable indicator of the beginning accumulation of fluid in the lungs is the PaO2 value.

The first priority is treatment of the underlying disease (for example, heart failure).

Along with this, there are a number of measures with which they try to eliminate edema:

Table 11. Table salt content in various diets

Natural content in regular food without added salt:

3 g table salt/day" 51 mEq sodium

Regular food, but with special unsalted bread:

1 g table salt/day = 17 mEq sodium

Rice-fruit diet:

practically salt-free" 10 mEq/day

Establishing a negative sodium and water balance by limiting the delivery of sodium and water (Table 11). Plasma electrolyte levels should be determined frequently. With very strict restriction of salt in the diet and drug-stimulated natriuresis, sodium deficiency can develop. In this case, the diet needs to be expanded, and sodium even added;

Compensation of protein deficiency (human serum albumin), especially for the treatment of edema in liver cirrhosis, nephrotic or starvation edema;

Stimulation of salts and water with osmodiuretics (infusion solutions of sorbitol and mannitol) and diuretics (Table 12, Fig. 42).

Table 12. Single doses, dosage limits, time of maximum action, duration of action and special side effects of some diuretics (according to Kruck, Leppla, Werning und Siegenthaler)

Rice. 42. Effect of diuretics on the nephron (according to Sherlock).

Overhydration is an excessive accumulation of fluid in the body taken in large quantities. In rare cases, water can harm the human body. But like anything else, too much can be inappropriate and even dangerous for the body. Moderation in everything is the main rule in life.

Classification of overhydration

isosmolar - increased fluid content at the extracellular level of the body, with normal concentrations of cations, anions and non-electrolytes. Often, such a disorder is characterized by a short-term manifestation and is promptly eliminated by the body if the systems responsible for water balance are functioning well;
hypoosmolar - formed simultaneously at the cellular and extracellular levels, characterized by a serious violation of the dynamic balance, as well as membrane potential;
hyperosmolar - this type develops as a result of the forced consumption of sea water instead of drinking water, after which a rapid increase in the concentration of electrolytes occurs.

Causes of the disease

Common causes of overhydration are:

excessive intake of fluid into the body, which contains a low percentage of salts or their absence. Often, this condition develops after repeated use of liquid while drinking;
dysfunction of removing foreign and harmful substances from the body due to kidney dysfunction;
poor blood circulation, which causes swelling;
increased levels of the pituitary hormone, which is responsible for the regulation of water metabolism;
stagnant decrease in the contractile function of the heart muscle;
disruption of the liver structure due to the proliferation of connective tissue.

The risk group includes people who adhere to a strict diet and also perform high physical activity.

Characteristic symptoms of overhydration

In the event of overhydration, the following is observed:

increase in total mass;
development of edema;
increased drowsiness;
the volume of urine produced over a certain period of time decreases;
low sodium levels in the blood;
the amount of fluid, which represents the external environment for most cells of the body, increases, which is why swelling develops.

With intracellular hyperhydration the following is observed:

excess fluid in the cells of the brain or spinal cord;
increased fluid content in the pulmonary interstitium;
impairment of kidney function;
disturbances in the functioning of the heart.

With hyperosmolar overhydration the following is noted:

High thirst;
temperature increase;
skin redness;
high blood pressure;
mental disorders.

With hyposomolar overhydration the following is noted:

feeling of nausea;
gagging;
stomach upset;
a categorical turn away from water;
lethargy, weakness, poor sleep.

With normosmolar overhydration the following is noted:

persistent increase in blood pressure;
excessive accumulation of fluid in body tissues.

Complications of overhydration

The most dangerous complications of overhydration:

increased blood and plasma volume;
severe intoxication of the body resulting from insufficient renal function;
disorders of the liver and kidneys;
Cases of death have been observed.

That is why at the first signs of the disease you should seek advice from a specialist.

Diagnosis of the disease

The main goal of diagnosis is to identify evidence of increased blood volume. If this phenomenon is observed, an excess of sodium is noted, which prevents the penetration of water into the intracellular cavity.

The following methods allow you to diagnose overhydration:

kidney diagnostics using ultrasound;
X-ray examination of the kidneys and urinary tract;
X-ray examination of the bladder.

Treatment of overhydration

If the disease is mild, therapy is not prescribed, since the body itself is able to normalize the amount of fluid in the body. If the following symptoms are observed:

migraine;
manifestation of aggression;
lack of clarity and coherence of thinking;
the feeling of your own body moving in space,

Patients should avoid excessive fluid intake.

The following treatment methods are also used:

blood purification and filtration using a special artificial kidney apparatus;
drinking mineral water to replenish water and electrolyte balance;
Consuming small amounts of salt in patients who perform strenuous exercise.

Treatment of overhydration with medications

If severe cases of overhydration are observed, drug therapy, mainly diuretics, is prescribed. This method of treatment allows you to restore the water and electrolyte balance of the body.

In extreme cases, a set of measures may be prescribed to eliminate the symptoms of the disease.

Traditional methods of treating hyperhydration

Disease prevention

The following methods will help prevent the development of overhydration:

careful control over one’s own actions, especially during attacks of severe thirst and other signs of illness;
food consumption in a certain sequence and totality;
control of your own weight and appearance;
limiting heavy physical exercise.

Features of overhydration in children

When the disease occurs in children, the following symptoms may occur:

disorders of consciousness leading to disruption of adequate reflection of objective reality;
a life-threatening condition characterized by loss of consciousness and severe weakness;
involuntary muscle contraction accompanied by severe pain;
clinical signs of meningeal irritation;
disruption of water-salt and other types of metabolism in the brain;
decreased myocardial contractility;
disruption of water exchange between body environments.

Water retention in the body (hyperhydration, hyperhydria, water depletion) is observed with excessive introduction of water (water poisoning, water intoxication) or with limited fluid excretion from the body. In this case, visible and hidden swelling and dropsy may develop.

Water poisoning (intoxication). In humans and animals, water poisoning occurs when the intake of water into the body exceeds the ability of the kidneys to remove it. Excessive water load increases the volume of circulating blood (oligocythemic hypervolemia), The content of blood proteins and electrolytes, hemoglobin decreases relatively, hemolysis of erythrocytes and hematuria occur. This condition is accompanied by the development hypoosmolar hyperhydration, the transition of water into cells with the subsequent appearance of signs intracellular edema.

In the case of a decrease in the osmotic concentration of body fluids below 300 mOsmol/l (with an increased mass of total body water), we speak of hypoosmolar hyperhydration.

An increase in the total water content in the body can be observed while maintaining its normal osmotic concentration (300-330 mOsmol/l). In this case, there is isosmolar hyperhydration. This condition is observed, for example, with an increase in hydrostatic pressure in the capillaries and an increase in the process of filtration of fluid from the vessels into the interstitial space (for example, with right heart failure). Accumulation of isotonic fluid in tissues occurs with a sharp decrease in oncotic pressure in the blood (loss of protein through the kidneys, cirrhosis of the liver, protein starvation, etc.), with an increase in the permeability of the capillary wall (diffuse capillaritis with glomerulonephritis), with difficulty in lymphatic drainage (blockage of lymphatic vessels, for example, round filaria worms, metastases to lymph nodes and lymph vessels - see the mechanism of development of edema). Iso-osmolar hyperhydration can develop after the administration of excessive amounts of isotonic solutions (improper correction of water-electrolyte disturbances).

Hypotonic overhydration characterized by the accumulation of water in the body without proportional retention of electrolytes. The leading mechanism in the development of “water poisoning” is the predominance of the positive component of the water balance over the removal of fluid from the body. The reasons for such an imbalance may be:

1) excessive intake of water into the body due to its increased consumption or overly active treatment of dehydration (especially associated with loss of electrolytes), salt-free liquids or drinks. The picture of disorders is aggravated if it occurs against the background of limited renal function;

2) acute renal failure in various pathological conditions and various kidney lesions leading to anuria or oliguria;

3) injuries and postoperative conditions, in which hypersecretion of vasopressin, decreased excretory function of the kidneys, therapeutic infusions of salt-free liquids and other factors play a role in the development of hypotonic overhydration;

4) disturbances in the regulation of water-electrolyte metabolism, against the background of which water poisoning develops especially easily: with increased secretion of vasopressin, with adrenal insufficiency;

5) pronounced activation of catabolism in chronic diseases leading to exhaustion: starvation, tuberculosis, malignant tumors, cachexia. Losses of up to 15% of body weight sharply increase the potential for the development of hypotonic overhydration;

6) the combined effect of a salt-free diet and diuretics in the treatment of edema, which can transform isotonic overhydration into water poisoning.

hypotonic hyperhydration is associated with the primary accumulation of water occurring in the extracellular sector and not supported by an equivalent increase in salt content. This in turn leads to hypoosmolarity of the extracellular fluid and causes the fluid to move along the osmotic gradient into the intracellular sector, the volume of which increases. Hypervolemia INHIBITS the production of aldosterone and thereby reduces the reabsorption of sodium and chloride, which further aggravates hypoosmolarity. In this regard, the development of hemolysis and disruption of the urinary function of the kidneys is possible.

Water poisoning manifests itself mainly in symptoms of intracellular hyperhydration, which is accompanied by a deterioration in health and an increase in body weight. Neurological and mental disorders are leading: patients develop apathy, drowsiness, headache, anisocoria, confusion, coma. Muscle twitching, tremors, and convulsions may occur. Nausea increases after drinking fresh water, and sudden vomiting does not bring relief. There is no thirst, even to the point of aversion to water. The mucous membranes are moist.

Hyponatremia, hypokalemia and hypoproteinemia are detected in the blood, hemoglobin content and hematocrit decrease. The osmotic concentration of urine is reduced, and oliguria is often observed. In severe cases, pulmonary edema, hydrothorax, and ascites develop.

Complex of therapeutic measures in case of water intoxication, it should be aimed at removing excess water and restoring osmotic concentration. This is achieved by completely prohibiting the intake of liquids (thirst treatment), stimulation of sweating (hot applications, diaphoretics), and infusion of osmotic diuretics. Acute manifestations of hypotonic overhydration can be eliminated by intravenous administration of hypertonic saline solutions, but this is only permissible if the total amount of salts in the body is reduced.

Hypertensive overhydration characterized by a disproportionate retention of water and electrolytes in the extracellular sector, with a predominance of excess of the latter. This may be observed:

1) with enteral intake of saturated saline solutions (forced drinking of sea water);

2) in some situations associated with impaired renal function;

3) with acute renal failure, acute glomerulonephritis or with limited functional capacity of the kidneys (in the postoperative period), with the introduction of iso- or hypertonic saline solutions;

4) for tumors of the adrenal glands, accompanied by excessive production of aldosterone.

Pathophysiological mechanisms hypertensive hyperhydration can be presented in the following sequence: the predominance of electrolyte retention over the accumulation of water in the extracellular sector, causing hyperosmolarity, leads to the movement of water from the intracellular sector into the interstitial space. This creates intracellular dehydration and aggravates the picture of extracellular hyperhydration, which contributes to the development of edema.

Clinical picture characterized by the prevalence of neuropsychic disorders caused by dehydration of nerve cells. This is combined with symptoms of hyperhydration and hyperosmolarity of the extracellular sector. Patients are unbalanced, restless, excited; Possible confusion, development of convulsions, coma. Strong thirst is paradoxically combined with edema, most often of the lower extremities, but the development of pulmonary edema is also possible. The content of sodium cation and osmotic pressure in the blood plasma are increased.

Therapeutic measures should be aimed at restoring extracellular isotonia and returning water to the cells. It is necessary to limit the intake of salts into the body by prescribing an appropriate diet and prohibiting the administration of electrolyte solutions. The removal of salts from the body can be increased by prescribing saluretics and protein blood products (plasma, blood albumin). Pure water is recommended orally, infusions of sugar solutions without electrolytes are prescribed parenterally, it is preferable to use sorbitol or mannitol to stimulate diuresis.