Hypernatremia

Description:

The hypernatremia is an increase in concentration of sodium in plasma more than 145 mmol/l. Sodium  is main osmotically active agent of extracellular liquid and therefore the hypernatremia is followed by hyperosmolality of plasma. As the amount of osmotically active agents in a cell is constant, the hypernatremia leads to a water exit from cells.

Hypernatremia symptoms:

At increase in osmolality  of extracellular liquid water comes out cells and their volume decreases. Decrease in volume of cells of a brain is followed by the increased risk  of subarachnoidal and intracerebral bleeding. In this regard the main symptoms of a hypernatremia - consciousness disturbances,  weakness,  increase in neuromuscular excitability, focal neurologic symptomatology, are less often observed  epileptic seizures and  a coma. Patients can show complaints to  increase in volume of urine and  I am eager. For the unknown reasons patients with  the polydipsia caused  by the central not diabetes mellitus  prefer to drink water with ice. At patients with  the increased sweating,  a diarrhea or  an osmotic diuresis  the hypovolemia is possible. The lethality is very high if concentration of sodium in plasma exceeds 180 mmol/l.

Hypernatremia reasons:

Hypernatremia reasons:
Excessive (more than 12 g a day) intake of sodium in an organism as a result:
- Consumption with food and liquids (for example, at a food peresalivaniye, reception of mineral waters).
- Parenteral administration with the medical purpose (for example, NaCl solutions, other liquids and substances containing Na+).

Reduced removal of sodium from an organism owing to:
- A renal failure (for example, as a result of a glomerulonephritis, a nefronekroz).
- Renin hypersecretions.
- The increased formation of angiotensin.
- Aldosteronism.

Treatment of the Hypernatremia:

Treatment is directed to the termination of losses and elimination  of deficit of water. The amount of water necessary for elimination of its deficit is calculated on a formula:
Deficit of water = (Na+ пл-140) x OBO/140,
where Na+ пл - concentration of sodium in plasma,
OVO - the general content of water in an organism.

At the hypernatremia caused by water loss, the general content of water in an organism makes 40% of weight at women and 50% - at men. For example, at the woman weighing 50 kg at concentration of sodium in plasma of 160 mmol/l deficit of water makes:

(160-140) x (0,4 x 50)/140 = 2,9 l.

As well as at a hyponatremia, bystry elimination of disturbances is dangerous. Sharp reduction of osmolality of extracellular liquid is followed by moving of water to the nervous cells adapted for the increased osmolality thanks to process of osmotic adaptation. It can lead to brain hypostasis, epileptic seizures and permanent neurologic disturbances. In this regard deficit of water is eliminated during 48-72 h.
When calculating amount of the entered liquid consider the current losses. Speed of decrease in concentration of sodium in plasma should not exceed 0,5 mmol/l/h, or 12 mmol/l within the first days of treatment. The safest way of administration of drugs - inside, including via the nazogastralny probe. 5% of glucose, perhaps slow in/in introduction, or 0,45% of NaCl.
At the central not diabetes mellitus appoint desmopressin intranazalno.
One more way of decrease in a diuresis is a restriction of consumption of table salt and co-administration of thiazide diuretics in small doses. At a partial central not diabetes mellitus it is possible to appoint the drugs stimulating secretion of ADG or strengthening its action on kidneys - Chlorproramidum, Clofibratum, carbamazepine, NPVS.
At a nephrogenic not diabetes mellitus treatment of a basic disease or cancellation of the medicine which caused damage of kidneys can lead to improvement of their concentration ability. Reduction of a diuresis at a nephrogenic not diabetes mellitus can achieve restriction of consumption of table salt and co-administration of thiazide diuretics in small doses. At the same time there is some hypovolemia leading to increase in a reabsorption of salts and waters in a proximal tubule and to reduction of a diuresis.

NPVS break synthesis of prostaglandins in kidneys and by that strengthen action of ADG; at the same time osmolality of urine increases, and the diuresis - decreases. If patients with a nephrogenic not diabetes mellitus need purpose of lithium, amiloride as lithium gets into cells of collective tubules through natrium channels, sensitive to amiloride, can reduce its nephrotoxic action.