How Common Are Hyponatremia and Hypernatremia?

Hypernatremia is also called hypernatremia, and serum sodium concentration> 145mmol / L is hypernatremia. Hypernatremia is bound to be accompanied by an increase in plasma osmotic pressure, so it is also called hypernatremic hypertonic syndrome. Hypernatremia simply reflects an increase in serum sodium concentration, and the total amount of sodium in the body can increase, normal, or decrease. It is common in clinical practice to input too much sodium chloride solution, mainly with extracellular fluid, and tissue edema, pulmonary edema, and heart failure occur.

Causes of hypersodium

Insufficient water intake

Seen when the water source was cut off, the comatose patient did not know how to drink water, and no one helped with water intake or disease-induced swallowing disorders, and stopped water intake (including water in food).

2. Excessive water loss

It is common in diabetes insipidus, osmotic diuresis, diarrhea, vomiting, dysfunction of concentrated urine, and insufficient water supply.

3. Sodium excretion disorder

Reduced sodium excretion in patients with adrenal hyperfunction is often accompanied by an increase in blood sodium. Reduced sodium excretion is also seen in such patients, and its ability to release ADH is not impaired, except that the "osmotic pressure threshold" for releasing ADH is increased, that is, ADH is released when the osmotic pressure in the body increases to a higher level than normal people. This is clinically referred to as "idiopathic hypernatremia".

4. Too much sodium input

Common in NaHCO3 injection, excessive hypertonic NaCl input and so on. Patients are often accompanied by severe hypervolemia.

Clinical manifestations of excessive sodium

Patients may experience symptoms such as fatigue, headache, irritability, excitement, etc., which may appear earlier, and then gradually progress to tremor, convulsions, coma, and even death due to irreversible damage to brain tissue. Patients with intracranial hemorrhage may have localization symptoms. Nervous system examination may appear hyperreflexia, neck stiffness, positive vertebral tract signs and so on. In many cases, there are red blood cells and increased protein in lumbar puncture cerebrospinal fluid. Other symptoms vary depending on the underlying disease that caused the condition. For example, patients with diabetes insipidus have obvious polyuria, those with excessive skin dehydration have fever, and those with too much hypertonic NaCl or NaHCO3 injection have hypertension, dyspnea, cough and other heart failure symptoms.

Hypernatremia is mainly due to the hypertonic state caused by too high blood sodium concentration, which causes the water in the cells to be precipitated, resulting in cell dehydration, especially brain cell dehydration, which can cause a series of neurological symptoms. The faster the onset, the more pronounced the symptoms. As with hyponatremia, the symptoms of slowly occurring hypernatremia are generally relatively mild. This is because brain cells can transfer extracellular Na + K + into the cell at the same time, and can also synthesize many small molecules with Permeable substances are mainly inositol, glutamic acid and glutamine. They can participate in the composition of osmotic microparticles in cells, thereby preventing excessive cell dehydration and dysfunction.

Excessive sodium test

Physical examination

The prominent symptoms of hypernatremia in the early stage are thirst. In severe patients, symptoms of the nervous system are mainly due to dehydration of brain cells, such as irritability, drowsiness, hyperteninosis, increased muscle tone, and convulsions, seizures, and coma. Examination should pay attention to the patient's psychic manifestations and symptoms of skin dehydration, circulatory failure and so on.

2. Laboratory inspection

The increase of blood sodium concentration is generally above 145mmol / L, and the plasma osmotic pressure is also increased. The daily urine volume, urine routine and relative urine density should be measured. The renal function tests include urea nitrogen, muscle matching PSP and urine concentration and Dilution test, etc. Patients with suspected diabetes, primary aldosterone, and Cushing syndrome are also tested for endocrine function.

Diagnosis of hypersodium

There are the following characteristics in diagnosis:

Medical history

Enter too much sodium chloride solution, especially when renal function is low.

2. Clinical manifestations

The increase in extracellular fluid is the main cause of tissue edema, pulmonary edema and heart failure.

3. Auxiliary inspection

Elevated or normal blood sodium levels can be found.

Hypersodium treatment

In terms of treatment, targeted treatment should be based on hypernatremia caused by different reasons.

1. For natriuretic hypernatremia, the primary disease should be actively treated

Limit the input of sodium chloride solution, and give fast urine, sodium diureate, etc. to promote the excretion of sodium and water from the kidney. Pulmonary edema and heart failure should be treated with strong heart and diuresis.

2. For concentrated hypernatremia should be scientifically supplemented with water

And take measures to prevent the continued loss of water, so that excessive hyperosmosis can be reduced, if it can be taken orally, it is advisable to take it as much as possible. Intravenous isotonic sugar water can quickly reduce blood osmosis, but correcting severe hypernatremia too quickly can also lead to serious complications. Generally, blood sodium is reduced to near normal levels within 48 hours. According to the blood sodium level, the water deficiency can be calculated according to the following formula:

Water shortage = total water × ([PNa / 140] -1)

The overall water is different between men and women, and can be calculated based on 60 or 50% dry weight per kilogram, but it is usually safer to calculate 50% and 40% of the weight of each man and woman. For example, in a 60 kg male patient, the blood sodium is 168 mmol, and the amount of dehydration is 60 × 0.5 × (168 / 140-1) = 30 × (1.2-1) = 6L.

The type of fluid replacement varies according to the basic disease. Those who simply cause dehydration use 5% glucose water and inject a small amount of insulin if necessary. If combined with loss of salt, 3/4 of the total fluid replacement can be supplemented with 5% glucose water. The rest 1 / 4 saline. If you have low blood pressure, you should first add normal saline to improve tissue perfusion. Those with potassium deficiency can also add KCl, but pay attention to urine volume; meanwhile, adding KCl itself can increase the total osmotic pressure of the liquid components. Pay attention.

Prevention of excessive sodium

Too much sodium is often associated with other diseases, such as burns, craniocerebral injury, COPD, liver transplantation, hyperadrenocortical function, etc., so care should be taken to prevent electrolyte disorders when treating these diseases. Patients with symptoms of the disease should be treated in time to prevent further development and more serious diseases. Once hypernatremia is found in the early stage, all sodium-containing fluids should be stopped immediately and replaced with hypotonic fluids; those who cannot drink water by mouth can leave the gastric tube and continue to drip warm water to relieve hypernatremia and promote sodium Excretion; actively control infection and cool down; blood glucose monitoring, actively control blood sugar to normal range; after the edema period, the condition permits, discontinue hypertonic diuretics. Most patients can get better results through the above treatment, and can effectively prevent the further development of the disease.