Dehydration is a pathological condition that occurs when water losses exceed its intake. It is characterized by thirst, decreased diuresis, dry skin. In severe cases, symptoms such as hypotension, impaired consciousness, diffuse cyanosis are noted. Dehydration is diagnosed according to the results of a laboratory examination, which allows you to detect an increase in hematocrit indicators, a change in ABB. The level of central venous pressure is also taken into account. Specific treatment: replacement of CBV deficiency, normalization of hematocrit, correction of electrolyte disorders.
ICD 10
E86 Liquid volume reduction
General information
Dehydration of the body (dehydration, exicosis) is a pathology associated with an acute lack of fluid in the body. According to modern concepts, dehydration occurs already with a water deficit of 40-50 ml/ kg. At the same time, the patient’s body weight decreases by 4-5% of the initial one. The severity of the condition increases as the water balance is disturbed. Death occurs after the loss of 20-25% of the total volume of fluid contained in the blood, intercellular matrix and cells. The cause of death is tissue ischemia and metabolic disorders.
Causes
The main reason for dehydration of the body is an excessively high and rapid loss of water. More often, excicoses develop in hot climates, in people with chronic diseases or digestive disorders. Leading etiofactors:
- Intestinal infections. They account for about 48% of the total number of cases of dehydration. Fluid is lost with vomit and loose stools. Dehydration against the background of intestinal infections is usually detected in children under the age of 5-6 years. This is due to low compensatory capabilities in this category of patients.
- Extensive burns. Dehydration of the body occurs against the background of massive discharge of burn exudate, if the patient does not receive adequate infusion therapy. Symptoms of fluid deficiency are noted already at the II degree of thermal damage, if its area exceeds 10-15% of the body.
- Increased sweating. Occurs at elevated body temperature or being in rooms with high ambient temperature. Signs of dehydration appear after several hours of intense sweating without compensating for water losses due to heavy drinking.
- Malnutrition. Normally, a person loses about one and a half liters of fluid every day, even in the absence of factors that enhance its excretion. Dehydration of the body occurs if the daily intake of water is less than the volume of its excretion with urine, feces, sweat and other physiological secretions.
- Dyspnea. With each exhalation, a certain amount of water vapor is excreted from the body. The more exhalations a person makes, the more moisture he loses. This is due to dehydration in patients suffering from respiratory pathology, as well as in tourists during trips to mountainous areas.
Risk factors
There are a number of factors that increase the likelihood of dehydration. People exposed to them should drink a lot and consume liquid-rich foods (celery, cucumbers, tomatoes, bell peppers), as well as constantly monitor their condition. Conditions that provoke dehydration:
- living in a tropical climate;
- performing physical work in the heat;
- intensive sports;
- regular intake of diuretics;
- respiratory diseases;
- stay in the mountains.
At particular risk are patients who are on a ventilator for a long time. Insufficiently moistened breathing mixture dries the alveoli. Due to the activation of compensatory mechanisms, the formation of surfactant increases, which requires additional fluid consumption. Losses are compensated by constant infusion of saline solutions and humidification of the air coming through the device.
Pathogenesis
The loss of a large amount of water is accompanied by a decrease in the volume of plasma circulating in the vessels and an increase in blood viscosity. Cardiac output decreases, tissue microcirculation slows down. Hypoperfusion and ischemia of internal organs, including the brain, occur. There is a change in the balance of electrolytes, a decrease in the concentration of potassium, sodium, and calcium.
The lack of mineral salts leads to the appearance of symptoms of coronary pathology in the victim. Significant rhythm disturbances are noted. The conduction of the nerve impulse slows down, which causes a decrease in the tone of smooth muscles, the development of acidosis. After repeated vomiting with gastric contents, alkalosis is detected.
Classification
Dehydration of the body is divided into several large groups:
- along the course of pathology (mild, moderate, severe);
- for reasons (internal, external);
- by the presence of complications (complicated, uncomplicated).
The most common and clinically significant option is the classification of excicoses according to the concentration of blood electrolytes:
- Hyperosmolar form. The loss of water prevails over the loss of salts. The concentration of the latter in the blood increases. H2O is released from the cells and the intercellular space into the vascular bed. CBV decreases slowly, blood pressure remains within the normal range for a long time. Life-threatening symptoms occur with a pronounced violation of the water balance.
- Hypoosmolar form. The removal of salts proceeds faster than the loss of the liquid fraction. It is characterized by a rapid disturbance of consciousness and the appearance of other neurological symptoms due to swelling of the neurons of the central nervous system. Even with a relatively small shortage of water, severe circulatory insufficiency is noted.
- Isoosmolar form. Water and minerals are lost proportionally to each other. There is a decrease in extracellular space. The vascular reaction remains at a fairly high level. Characteristic symptoms are a decrease in diuresis and CVP against the background of preserved or slightly reduced blood pressure.
Dehydration symptoms
Light degree
With a lack of 40 ml of fluid per kilogram of body weight, the patient has the following symptoms: thirst, minor mental anxiety. The turgor of the skin is preserved, the mucous membranes are moist, the pulse is normal or slightly elevated. The time of the presence of a pale spot when pressing on the distal parts of the limbs is no more than 2 seconds.
Average degree
Dehydration is manifested by a decrease in diuresis to 1-0.5 ml / kg/h. The mucous membranes become dry, sticky, and the eyes sink in. Tachycardia is detected, tension and pulse filling decreases. Psychoemotional disorders become more pronounced. The person is restless or inhibited. The blood pressure level ranges from +/- 20% of the usual indicators.
Severe degree
Severe dehydration of the body is accompanied by mental retardation. The level of consciousness is sopor. External symptoms are progressing. The eyes become more sunken, the skin acquires a bluish hue. The skin temperature drops. The white spot persists for longer than 3 seconds, blood pressure is significantly lower than normal. The pulse is accelerated due to the activation of compensatory mechanisms. Deep, labored breathing.
Complications
Mild dehydration does not lead to the development of complications. Moderate processes increase the likelihood of blood clots with subsequent obstruction of the blood vessels of the heart, lungs, brain. Symptoms of severe exicosis are an indication for further observation of the patient by a neurologist. There is a risk of paresis, chronic headaches, and cognitive decline.
Diagnostics
Dehydration of the body is diagnosed on the basis of clinical and laboratory examination data. Symptoms of mild exicosis are detected by a district therapist or pediatrician during an independent visit of a patient to a medical facility. Severe and moderate processes are diagnosed by ambulance staff. To make a diagnosis , the following is used:
- Physical examination. There are characteristic clinical symptoms of dehydration. The patient reports the presence of repeated vomiting, diarrhea or other factors contributing to the excretion of water. Auscultation and percussion are uninformative. There may be some weakening of heart tones, but it is not present in all cases.
- Measurement of CVP. To determine the CVP, the Waldman apparatus is used. Normally, the pressure in the right atrium and subclavian vein ranges from 6 to 12 cm of water column. Its decrease by 2 or more centimeters indicates hypovolemia.
- Laboratory test. The highest diagnostic value is the level of hematocrit, which should not exceed 36-45% (depends on age). The growth of Ht indicates blood thickening due to fluid loss. A decrease in the concentration of electrolytes is also detected.
Treatment
Exicosis of any genesis and severity is treated conservatively. Patients with mild pathology are treated on an outpatient basis, all other categories of patients should be hospitalized. Significant disorders of hemodynamics and higher nervous activity require placing the patient in the ICU. Treatment methods:
- Oral rehydration. It is indicated for mild dehydration. It is recommended to use a large amount of salted liquid, pharmacy rehydrating agents.
- Infusion therapy. Indomitable vomiting, symptoms of significant dehydration are a direct indication for intravenous infusion of solutions. The volume of the latter depends on the degree of pathology and varies within 1-2.5 liters. Glucose solution, salt substances are used.
- Symptomatic therapy. If the patient has suffered severe tissue ischemia, neuroprotectors or cardiotropic drugs may be prescribed. In addition, a ventilator, administration of potassium preparations, artificial maintenance of vital functions may be required.
Treatment is carried out until the final stabilization of diuresis, hemodynamics and other vital signs. After replenishing the CBV, it turns out what led to the development of dehydration.
Prognosis and prevention
Mild dehydration has a favorable prognosis. With the timely start of therapy, the symptoms of pathology completely disappear within 1-2 days. With severe exicosis, the onset of persistent disabling complications and a fatal outcome is possible. Among the preventive measures is the use of 1.5 liters of water daily. Staying in hot rooms and exposure to other risk factors should be avoided. With prolonged diarrhea, rehydrating solutions are indicated.