Balance - disorders of water and electrolyte metabolism

In the body, electrolytes have an extremely important role in maintaining osmotic pressure, acid-base balance, and regulating neuromuscular excitability.

Water plays a very important role in participating in cell structure and organization, including maintaining normal body activities. In an experiment, mice died of thirst faster than starvation: You can fast completely for more than 30 days, but without water, the body will die after a few days. If the body loses 10% of water, it will enter a pathological state, if it loses 20-25% of water, it can die.
In the body, electrolytes have an extremely important role: maintaining osmotic pressure, acid-base balance, regulating neuromuscular excitability, etc. seriously affect the functioning of the body, even cause death.

Depending on age, the amount of water in the body varies. In infants, water accounts for approximately 80% of body weight (TLCT). Adults: 55-60%. In men: 60%, in women: 55%. In the elderly, the percentage of water is lower than in the young.
Water in the body is distributed into two compartments:
The intracellular compartment (TTB) accounts for 40%. The extracellular space (NTB) occupies 20% of which: 15% of the intercellular fluid (GB), 5% of the intravascular fluid (TLM) ie the circulating volume.

3.1. Types of water balance disorders
In clinical practice, disorders are often accompanied by electrolyte disturbances. Based on two basic types of water balance disorders, namely dehydration and excess water combined with fluctuations in the concentration of Na + outside the cells, people divide the following types of electrolyte disorders:
Hypotonic dehydration: Loss of water and electrolytes Water combined with Na+ deficiency in which Na+ loss is greater than water loss causes the blood to become hypotonic, the osmotic pressure of the serum is low, this will cause a decrease in extracellular water and an increase in intracellular water. due to water moving in. Isotonic dehydration: The loss of water and Na+ ions are equivalent. Hypertonic dehydration: Loss of water more than Na+, extracellular fluid volume decreases, blood is hypertonic, plasma osmolality increases, so water will shift from intracellular to extracellular, causing intracellular dehydration . Hyperhydration Hypotonic: Excess water causes increased volume of extracellular and intracellular fluid, decreased serum and intracellular fluid osmolality. Isotonic excess water: Excess water and excess Na+ respectively. Hypertonic water excess : Excess fluid and Na+ ions, serum osmolality and extracellular volume increase, causing displacement of water from the intracellular to the outside, reducing the intracellular volume and increasing the osmolarity of the intracellular fluid. cell. 3.2. Classification of degrees of water balance disorders
In surgical patients, the most common form of water and electrolyte imbalance is a state of water and electrolyte deficiency, in which hypertonic dehydration is the most common, often arise before or after surgery due to lack of food, inadequate water intake, vomiting, diarrhea, excessive sweating due to fever, increased breathing rate, etc.
Dehydration mild : When the water deficit is no more than 1-2 liters (2-3% of body weight). Clinical syndrome then may be thirst, dry mouth, decreased urine output, tachycardia.
Moderate dehydration: When the water deficit is from 3-5 liters (5-8% of body weight). Patients feel more thirsty, dry tongue, tachycardia, hypotension, weak pulse, fatigue, oliguria, peripheral circulatory disturbances.
Severe dehydration: A lack of water 8 liters or more (8% of body weight). At this time, the clinical picture is hypovolemic shock, hyperosmolar coma, loss of consciousness, delirium, hallucinations, psychomotor arousal, metabolic acidosis, anuria, fever, and hypotension. , rapid pulse.

3.3.Tests to detect disorders of water balance
increased Na+ and increased Cl-, increased plasma osmolality. Blood protein and hematocrit were normal.

Increased blood sodium levels
Hypernatremia is usually caused by an imbalance between the amount of water taken in and the amount of water excreted from the body. Hypernatremia is accompanied by increased osmotic pressure. Symptoms seen in the elderly are often subtle. Common causes
Hypernatremia with hypovolemia (water deficit > sodium deficiency) Decreased water intake: Lack of water intake or impaired thirst mechanism (nervous system damage) center).

Changes in body water are divided into 2 broad categories:
5.1. Extracellular Dehydration
Hypertonic dehydration (loss of water more than salt loss) occurs in:
Heavy sweating (hot weather, high fever, heavy labor, etc.) can take up to 14 liters/24 hours (with 35 g of NaCl). In diabetes insipidus, the patient excretes a very dilute urine volume (sometimes up to 10-14 liters in 24 hours). When the water supply is not enough while the body continues to lose water (through the skin, lungs, kidneys, etc.) it is the case that the patient is unconscious, debilitated, unable to drink water or unable to keep drinking water. , etc... In the above cases, the body loses more water than salt, causing extracellular hypertonic state, calling extracellular water out (causing cellular dehydration) until osmotic equilibrium is reached. between the two regions were re-established. Isotonic dehydration (water loss and salt loss proportional to each other) occurs in digestive disorders, vomiting (mainly loss of Cl), loose stools (mainly loss of Na), gastrointestinal fistula, etc. Severe vomiting and diarrhea may result in a loss of 15% of total sodium, 28% of total chloride, and 22% of total extracellular fluid.
Hypotonic dehydration when salt loss is more than dehydration: It is a case of adrenal insufficiency (Addison's disease, dehydration and salt but only water and no salt supplementation, etc.). In this type of dehydration, due to extracellular hypotonicity, water from the extracellular space enters the cell (causing increased cellular water absorption) to restore osmotic equilibrium.
5.2. Cellular dehydration:
Cellular dehydration arises due to dehydration (different from extracellular dehydration with both dehydration and electrolyte loss) or salt accumulation in the body. Both of these causes increase the extracellular osmotic pressure (extracellular hypertonicity), which causes water to move from the cellular area to the extracellular space causing cellular dehydration. Cellular dehydration is often associated with extracellular dehydration.

In healthy individuals, fluid volume and electrolyte concentrations are maintained within strict limits by interactions between several organ systems.
Total body water can be divided into 2 compartments according to the limits of the cell membrane:
Extracellular fluid is the fluid outside the cells, accounting for 1/3 of the total body water. Extracellular fluid is further divided into: plasma 20% and interstitial fluid 80%. Intracellular fluid is the fluid inside cells, making up two-thirds of the body's water weight. Periodic health check-ups help detect diseases early, thereby planning treatment for optimal results. Currently, Vinmec International General Hospital has general health checkup packages suitable for each age, gender and individual needs of customers with a reasonable price policy.
The patient's examination results will be returned to the home. After receiving the results of the general health examination, if you detect diseases that require intensive examination and treatment, you can use services from other specialties at the Hospital with quality treatment and services. outstanding customer service.