Disorders of the water and electrolyte balance are extremely rarely a primary disease, a disease in itself, much more often as a result of other serious ailments, medications or inadequate nutrition. Long-term, slowly increasing changes in electrolyte levels are usually asymptomatic, unless the rise or fall is very large. If, on the other hand, these fluctuations are rapid, even if the exceeding of the norm is small, they may cause serious symptoms. It is worth finding out how important a properly functioning water and electrolyte balance is in our body, and therefore what the symptoms of its disorders may be and why they can be dangerous to he alth and life.

Water and electrolyte disturbancesare the result of other, usually serious diseases affecting the kidneys, digestive or endocrine system. In the context of water and electrolyte management, there are states of dehydration, fluid overload and electrolyte disturbances related to: sodium, potassium, magnesium and phosphorus.

Abnormal electrolyte values ​​obviously require treatment in the form of emergency correction of disorders, but the overriding principle is to try to remove the cause, because it gives a permanent cure.

Treatment of electrolyte disturbances consists in removing them from the body - in cases of excess, and delivering them in the case of a deficiency, but it is a symptomatic procedure. If the cause is not removed and symptomatic treatment is delayed, the symptoms will recur.

Electrolyte changes are very unfavorable for our body, because they can lead to changes in the charges of cell membranes and electrical potentials between cells, and consequently to disturbances in nerve conduction and muscle cramps. In addition, electrolytes are a building and energy material.

It is worth remembering that not all disturbances in ion concentration are symptomatic, and if the deficiency or excess increases for a long time, it is usually asymptomatic. Then the therapy is not necessary or requires only a slight diet correction.

Large electrolyte shifts can even be life threatening, as they sometimes cause impairment of the functions of the nervous system or the heart muscle. In such a case, immediate therapy and quick correction of the lesions is necessary.

It's worth itremember that changes in electrolyte concentrations caused by an improper diet, in the absence of other diseases, are usually small and do not require intensive treatment.

It should be emphasized once again that electrolyte shifts that threaten he alth and life result from serious diseases, usually of the digestive system or kidneys. In such cases, patients are under the care of doctors who monitor changes in ion concentrations and start treatment if necessary.

Water and electrolyte disturbances: basic concepts

Under normal conditions, body fluids are electro-neutral, iso-osmolar and isoionic.

Electronutralitysays that the flow of ions through biological membranes takes place in such a direction that the sum of the concentrations of negatively charged (Cl-, HCO3-) and positive (e.g. K +, Na +) on both sides of the membrane was identical (so that the charges were neutralized). The electrolyte state is of the greatest importance in the context of electrolyte economy.

Isoosmolalitymeans the identity of the osmotic pressure in all water spaces, a change in the amount of osmotically active substances in one space causes the fluid to shift and the osmotic pressures to equalize again.

The osmolality of body fluids is physiologically about 280-295 mmol / kg H2O, in the plasma it is responsible for sodium, glucose and urea. If the osmolality of the fluid is lower than physiologically - we say hypotonia, and if greater - hypertonia, these terms are usually used in the context of overhydration and dehydration.

The last term -isojoniais a constant concentration of ions, most often referred to in the hydrogen economy.

Why is the stability of ion concentrations so important?

The intracellular and extracellular spaces contain a certain amount of electrolytes: positive ions (cations) and negative ions (anions).

Despite the law of electroneutrality, the specific structure of the cell membrane (e.g. ion transporters located within it) makes the sum of charges on both sides different.

This difference is called the membrane potential, and it is maintained thanks to the aforementioned structure of the cell membrane, which prevents the flow of ions and transporters (e.g. sodium-potassium pump) that constantly move ions into and out of the cell.

The action of a stimulus (electrical, mechanical or chemical) upsets this delicate balance and changes the permeability of the cell membrane.

The result is an immediate, avalanche-like displacement of charges through the cell membrane, which is spreading along the entire length of the cell, i.e.action potential (nerve impulse).

It is the primary mechanism responsible for the conduction of nerve impulses and muscle contractions. This is why significant electrolyte disturbances have such a large impact on the functioning of our body - both the nervous system and muscles.

Water and electrolyte disturbances: dehydration

Dehydration is a condition in which the amount of water in the body is too small and there are various mechanisms for this. They are related to water loss, but differ in the accompanying electrolyte disturbances resulting from different mechanisms of fluid loss, and hence the proportion of water and electrolytes remaining in the body.

Depending on this ratio, the following arises:

  • isotonic dehydration , as the name implies, the loss of electrolytes is proportional to the loss of water, so the molality of the plasma is as it is at equilibrium. The mentioned molality is the concentration of osmotically active substances contained in a kilogram of solvent - water. Such dehydration usually occurs through the digestive tract - diarrhea, through the kidneys - polyuria, skin - burns, or through the mechanism of fluid transfer to the so-called third space, when edema occurs. Treatment consists of replacing lost fluids and treating the cause of water loss.
  • hypertonic dehydration , in this case there is a loss of a disproportionate amount of water in relation to the osmotic substances, and their excess remains in the body, as a result of which the tonicity of body fluids increases. This, in turn, leads to the displacement of water from the intracellular space to the extracellular space and dehydration of the cells. The reasons are, for example, insufficient fluid intake, or loss by the kidneys (diabetes insipidus), hypertonic dehydration is accompanied by a strong thirst, such as the expression of an attempt to compensate for osomolality (concentration of osmotically active substances) by increasing the amount of solvent. If dehydration develops rapidly, neurological symptoms may occur - disturbances of consciousness or hallucinations. Treatment consists of fluid replacement, preferably hypotonic ones - orally and intravenously.
  • hypotonic dehydration , it is a shortage of water accompanied by a reduced molar efficiency of plasma (it is hypotonic in relation to the normal state), i.e. the amount of osmotically active substances is too small. This leads to the infiltration of water into the cells (as an attempt to equalize the osmotic pressure), which is especially dangerous for the brain as it can lead to swelling. The treatment for hypotonic dehydration is the administration of increased fluidssodium concentration.

A group of symptoms is common to all types of dehydration, including:

  • increased thirst
  • dry mucous membranes and skin
  • low blood pressure
  • accelerated heartbeat
  • passing small amounts of urine

Quite rarely, and only in advanced states, other symptoms appear - the aforementioned disturbances of consciousness or hallucinations.

In terms of therapy, apart from immediate fluid replenishment, it is necessary to cure the cause of the ailments, otherwise dehydration will recur.

Water and electrolyte disturbances: fluid overload

It is a condition in which the amount of water in the body is too high, as in the case of dehydration, the cause of this condition affects the amount of electrolytes excreted, and thus the change in their concentrations in intra-body fluids.

The following is therefore distinguished:

  • isotonic overload , in which the volume of the extracellular space increases, the amount of osmotic substances increases proportionally. This state of affairs leads to the appearance of edema. As a result of heart failure, liver diseases or kidney diseases, sodium and a proportional amount of water accumulate in the body. In treatment, the most important thing is to eliminate the cause of hyperhydration, as well as to administer diuretics efficiently and to reduce fluid intake.
  • Hypertonic hyperhydrationis a very rare water disorder because it can be caused by the administration of liquids with an increased molality, e.g. by drinking sea water or while feeding through a gastric tube. The intracorporeal fluids are then hypertonic, which causes dehydration of cells and an increase in the extracellular space. This excessive amount of fluid causes edema, increases in blood pressure and increases neurological symptoms (due to contraction of the neurons). Treatment consists of removing excess sodium and water through diet, diuretics and, exceptionally, dialysis.
  • hypotonic hyperhydration , i.e. water poisoning occurs when the amount of water is disproportionate to the amount of sodium in the body, it causes hyponatremia and a reduction in the molality of body fluids. Most often, this condition occurs in the presence of kidney disease or abnormally high secretion of the hormone vasopressin, which results in insufficient excretion of so-called free water. In short: the body's electrolytes are removed, but disproportionately little water is removed. Treatment consists of sodium supplementation and possible administration limitationliquids.

The diagnosis of both dehydration and hyperhydration is based on finding the cause of the condition, as it allows, on the one hand, to hypothesize about the osmolality of body fluids, and, on the other hand, to initiate therapy.

Determination of serum osmolality, as well as electrolyte levels, especially sodium, in venous serum or blood gas tests helps in differentiating whether it is a hyper- or hypotonic state.

Disruptions in the soda economy

Sodium is an important electrolyte, being the main factor influencing the electrical potential of fluids and their osmolality. Its role is due to the fact that it is the basic cation in the extracellular fluid and an important osmotically active substance.

In addition, sodium plays a key role in the transmission of nerve impulses and muscle contractions, thanks to its positive charge and the ability to penetrate the cell membrane.

The norms of concentration of this ion in the serum are about 135-148 mmol / l.

  • Hyponatremia

Reducing the amount of sodium in the body is called hyponatremia, and in most cases it results from an excess of water in relation to sodium (hypotonic overload).

The most common cause is inadequate secretion of the antidiuretic hormone, which inhibits water excretion with excessive sodium removal from the body.

Depending on the time of increasing sodium deficiency, we can distinguish acute and chronic hyponatremia, which is important due to the severity of the symptoms of this condition and the method of treatment.

If the hyponatraemia lasts long, the symptoms are mild - usually disturbance in concentration, sometimes balance, but if the condition develops rapidly (within 48 hours), the effects can be very serious:

  • headaches
  • convulsions
  • coma

In addition, depending on the cause, sodium deficiency is also accompanied by a change in osmolality - the tonicity of intracorporeal fluids and volemia, i.e. the amount of body fluids.

Due to the fact that sodium is the most important osmotically active substance, its reduction causes hypotension and swelling of cells due to the influx of water into them.

In the diagnosis of hyponatremia, the determination of this electrolyte in the blood is of course used, it is also necessary to determine the serum osmolality, and sometimes also the urine osmolality.

This allows us to determine the most likely cause and implement appropriate treatment aimed not only at correcting electrolyte disturbances, but most of all at removing the underlying cause of this condition.

Waythe therapy depends mainly on the time of the development of hyponatremia and symptoms, apart from the causal therapy, sodium drips are used, but they should be administered very carefully, because too quick correction of hyponatremia can be life-threatening.

Treatment is not always necessary if symptoms are not severe or absent.

  • Hypernatremia

It most often occurs as a result of water loss, e.g. in increased sweating, severe vomiting and diarrhea, diabetes insipidus, or in the case of insufficient water intake.

As in hyponatremia, the severity of symptoms depends on the dynamics of the disorder, if it is a slowly developing condition, it may not cause any discomfort.

In urgent cases, there is a disturbance of consciousness, nausea and vomiting, and sometimes even coma. Treatment of hypernatremia is based on removing its cause and appropriate fluid therapy.

Potassium disorders

Potassium is the main intracellular cation and one of the four basic osmotically active substances.

As in the case of sodium, its primary role is to contribute to the contraction of muscles, including the heart muscle, as well as smooth muscles (present in the gastrointestinal and urinary tract, among others).

The role of potassium in transmitting nerve impulses is equally important, and it is also a component of many enzymes. Laboratory norms for serum potassium levels are 3.8 to 5.5 mmol / L.

  • Hypokalemia

Excessive loss of water, usually of electrolytes, by the kidneys is the most common cause of hypokalemia, there are many reasons for this condition:

  • diuretics
  • hyperaldosteronism (hyperadrenocorticism)
  • genetic diseases, e.g. Gitelman syndrome

Due to the risk of impaired potassium levels, it is necessary to measure serum electrolytes when taking diuretics.

Another way to eliminate potassium is through the digestive tract, so diarrhea can also contribute to serious electrolyte disturbances.

Very rarely, hypokalemia occurs as a result of dietary deficiency or electrolyte shifts - the influx of potassium into the cells.

Symptoms of hypokalemia do not always occur, if it is a slowly progressive chronic condition, it can be completely asymptomatic. If the deficiency is so severe that it affects the resting potential of nerve and muscle cells, as well as the acid-base balance, very serious complications may occur, including:

  • arrhythmias
  • muscle weakness
  • gastrointestinal complaints including intestinal obstruction

Diagnosis is made on the basis of laboratory tests, it is important to determine other parameters of the electrolyte and acid-base balance in the case of potassium level disturbances. Depending on its intensity, potassium is supplemented with oral preparations or intravenous drip.

  • Hyperkalemia

Increased potassium levels have many causes, the most common being:

  • kidney failure
  • endocrine system disorders (hypoaldosteronism, i.e. adrenal insufficiency)
  • taking certain medications for high blood pressure or coronary artery disease
  • excessive intake of dietary supplements containing potassium

Therefore, during therapy with potassium preparations and in serious kidney diseases, regular determination of serum electrolytes is necessary.

By affecting the resting potential of muscles and nerves, hyperkalemia causes muscle weakness, cardiac arrhythmias and paraesthesia (tingling) and sometimes disturbed consciousness.

The finding of hyperkalemia leads to a more detailed diagnosis in order to find out the cause of this condition and to detect any other electrolyte or acid-base disturbances.

The first treatment is to remove the cause and limit the supply of this element. If the concentrations are high enough to cause cardiac arrhythmias, medications that bind potassium in the blood (they cause its "inactivation") and diuretics to remove the excess ion are administered.

Disorders of the magnesium economy

Magnesium has many functions: it participates in energy processes, the synthesis of nucleic acids and proteins, it is a building block of bones and, like sodium and potassium, it participates in the transmission of signals in the nervous system, as well as in the contraction of muscle fibers.

Magnesium is mainly an intracellular ion, but its participation in the formation of the resting potential is smaller than in the case of the above-mentioned elements. The norm of serum magnesium concentration is 0.65-1.2 mmol / L.

  • Hypomagnesaemia

Hypomagnesaemia is rare, it may be the result of a dietary deficiency, malabsorption, or excessive loss in the urine or through the digestive system.

The diagnosis of magnesium abnormalities is quite difficult, because it is an intracellular ion and only large changes in the amount of magnesium in the body can be detected in laboratory tests.

Symptoms are similar to wother electrolyte disturbances, but in this case they only occur with very large fluctuations in the amount of magnesium:

  • heart rhythm disturbance
  • muscle weakness and spasms

Treatment usually does not require immediate action, a proper diet or supplementation with pills is sufficient. On the other hand, if the deficiency of this element leads to dangerous symptoms, including cardiac arrhythmias, intravenous administration of magnesium s alts is necessary.

  • Hipermagnezmia

Too high concentration of magnesium is extremely rare, the most common causes are: excess in the diet (most often with too intensive supplementation) and impaired kidney function causing its inappropriate removal.

Symptoms are similar to deficiencies: disturbances in muscle strength and sensation, and disturbances in heart rhythm. In their case, intensive treatment of hypermagnesaemia is necessary by stimulating magnesium removal

Disorders of the calcium economy

Calcium together with sodium and potassium is responsible for the proper functioning of muscles and nerves - it takes part in the transmission of impulses and in the contraction of muscle fibers.

Moreover, it is one of the basic components of bones, responsible for enzymatic processes and blood clotting.

The correct concentration of calcium in the serum is 2.25-2.75 mmol / l, it is only about 1% of the calcium contained in our body, because most of it is in the bones and intracellularly.

The following are responsible for the calcium metabolism: the endocrine system, gastrointestinal tract, kidneys and vitamin D.

  • Hypocalcemia

The most common cause of calcium deficiency is insufficient amount in the diet, other causes of this condition may be:

  • malabsorption
  • kidney disease
  • hormonal disorders, especially in the parathyroid glands

Severe hypocalcemia is manifested by tetany, i.e. numbness and muscle spasms, including the throat, sometimes also photophobia, asthma attacks or abdominal pain.

If your calcium deficiency is mild and chronic, it may not cause any symptoms. Symptomatic hypocalcaemia is an emergency, and is treated immediately by replacing calcium deficiency, usually intravenously.

  • Hypercalcemia

The excess of calcium in the serum results most often from disturbances in the concentration of parathyroid hormone, and therefore most often from hyperparathyroidism, less often it is the result of a protein similar to parathyroid hormone produced by tumors, which has an identical effect, causing an increase in the amount of calcium inplasma.

The symptoms of hypercalcemia are:

  • renal dysfunction
  • digestive tract disorders (nausea and vomiting, peptic ulcer disease)
  • hypertension
  • muscle weakness

Treatment is, in addition to forcing diuresis and removing calcium from the body, inhibiting the release of this element from the bones with drugs used, for example, in osteoporosis.

Disorders of the phosphate economy

Phosphorus compounds have several functions in our body, the most often talked about their role in building bones and teeth, but they also play an important role in the acid-base balance, the PO43- ion is one of the main intracellular anions.

In addition, phosphorus is a component of nucleic acids (DNA and RNA) and an energy carrier (adenosine triphosphate).

Normal serum phosphate values ​​are 0.9-1.6 mmol / L.

  • Hyperphosphatemia

The most common cause of hyperphosphatemia is renal failure, so the inability to remove excess phosphorus from the body, hypoparathyroidism is less common, which also reduces the amount of phosphate excreted in the urine.

Symptoms of hyperphosphatemia often do not occur at all, and among the ailments, the symptoms of the underlying disease, such as kidney failure, come to the fore.

In treatment, the key is to remove the cause and reduce phosphate in the diet, sometimes substances are used to bind phosphate in the digestive tract, which prevents their absorption.

  • Hypophosphatemia

Hypophosphatemia, or phosphate deficiency, usually results from a deficiency of this compound in the diet, less often as a result of malabsorption or loss by the kidneys.

As mentioned, phosphates play a significant role in energy processes, therefore their deficiency leads to the disturbance of the processes in which energy consumption is greatest: muscle contractions (paralysis or weakness occurs) and the functioning of the nervous system (convulsions and sometimes also coma).

In terms of treatment, hypophosphatemia does not differ from other electrolyte disorders - usually oral supplementation and causal treatment are used.

Category:

Cardiology