Increased serum sodium

Introduction It reflects the increase of serum sodium concentration, and the total amount of sodium in the body can be increased and normal, and it can also reduce the importance of maintaining extracellular fluid volume, regulating acid-base balance, maintaining normal osmotic pressure and cell physiological function, and participating in maintaining nerves. Normal stress of the muscles.

Cause

The cause of elevated serum sodium

1 The body fluid capacity caused by dehydration is reduced.

2 Disease caused: Kidney diseases such as acute and chronic glomerulonephritis with sodium and water retention, but due to water retention at the same time, clinical detection of serum sodium can be no significant change. Endocrine diseases, such as primary or secondary aldosteronism, high blood sodium; Cushing's syndrome may have mild serum sodium, or long-term use of adrenocortical hormone to make renal tubular sodium reabsorption, resulting in serum sodium High. Brain injury can cause hypernatremia, due to osmotic pressure regulating central disorders, becoming traumatic diabetes insipidus, urine can not be concentrated, fluid loss, serum sodium increased, plasma osmotic pressure increased, and hypotonic urine. In this case, even if a large amount of water is hydrated, it is difficult to normalize serum sodium.

an examination

Related inspection

Serum sodium serum sodium (Na+, Na) blood routine

Examination of elevated serum sodium

(1) Reduced body fluid capacity, such as dehydration.

(2) Kidney diseases, such as acute and chronic glomerulonephritis, with sodium and water retention, but due to water retention at the same time, clinical detection of serum sodium can be no significant change.

(3) Endocrine diseases, such as primary or secondary aldosteronism, hypernatremia; Cushing's syndrome may have mild serum sodium elevation, or long-term use of adrenocortical hormone to reabsorb renal tubular sodium, and Caused high serum sodium.

(4) Brain injury can cause hypernatremia, due to osmotic pressure regulating central disorders, becoming traumatic diabetes insipidus, urine can not be concentrated, fluid loss, serum sodium increased, plasma osmotic pressure increased, and hypotonic urine . In this case, even if a large amount of water is hydrated, it is difficult to normalize serum sodium.

Differential diagnosis

(1) Diabetes insipidus

Also known as pituitary diabetes insipidus, is the lack of ADH secretion in the posterior pituitary, the cause of which is unknown. The clinical features are polydipsia, polydipsia, polyuria (daily urine volume up to 5-10 L), low urine relative density (1.001 to 1.005), and low urine osmotic pressure (50-200 mmol / L). Clinically divided into idiopathic diabetes insipidus and secondary diabetes insipidus, the latter is caused by hypothalamic pituitary tumors, brain trauma, surgery, inflammation, when the lesions involve the hypothalamic thirst center and lose thirst When feeling, it is often unable to replenish water in time, resulting in severe dehydration and even death. When suspected diabetes insipidus, the vasopressin test and plasma ADH should be used to confirm the diagnosis. If necessary, CT and X-ray examination should be performed to exclude pituitary tumors.

(two) renal diabetes insipidus

For hereditary diseases, clinical manifestations are similar to those of diabetes insipidus. Most of the patients are boys, and the disease occurs several months after birth. After the injection of vasopressin, the urine volume is not reduced, the urine specific gravity is not increased, and the plasma ADH concentration is significantly increased, which can be differentiated from pituitary diabetes insipidus.

(3) Interstitial nephritis and severe renal dysfunction

Caused by a large number of causes, in addition to pyelonephritis, drugs (salt, demethyl chlortetracycline, etc.), low potassium, high calcium, urinary tract obstruction, gout, etc. can cause this disease. Hypernatremia, polyuria, and dehydration. According to the medical history, renal function tests and serum electrolyte measurements can be used to differentiate the diagnosis.

(4) Diabetic hyperosmolar coma

More common in elderly patients, mild diabetes before the onset of the disease or even do not know diabetes, often caused by infection, the use of diuretics or glucocorticoids. In addition to hypernatremia and dehydration, the clinical manifestations are mainly neurological symptoms, such as unconsciousness, lethargy, hemiplegia, aphasia, convulsions, etc., which are easily confused with cerebrovascular accidents. This disease should be differentiated from hypernatremia caused by osmotic diuretics.

(5) Idiopathic hypernatremia

The cause is unknown and clinically rare. The diagnostic criteria are: 1 persistent hypernatremia; 2 no significant dehydration and thirst; 3 urine becomes hypertonic when banned, indicating that the body still has the ability to secrete ADH; 4 renal tubules still respond to ADH When vasopressin is applied, it can cause water retention. There is a group that believes that this disease is the "threshold increase" of ADH release.

In addition, it should be differentiated from secretory diseases such as primary aldosteronism and hypercortisolism.

1. History: Insufficient sodium chloride solution, especially when kidney function is low.

2. Clinical manifestations: The increase of extracellular fluid is common, so tissue edema, pulmonary edema and heart failure often occur.

3. Auxiliary examination: It can be found that the blood sodium content is elevated or normal.

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