What syndrome is accompanied by loss of consciousness

     Loss of consciousness becomes commonplace. It is commonly associated with fatigue, hypoglycemia, pregnancy, dehydration, or cardiovascular disease. But few people remember in such cases the syndrome of inappropriate secretion of antidiuretic hormone (ADH), in which the main symptom is loss of consciousness. What is the syndrome of inappropriate secretion of ADH? How to identify it? How to live with such a syndrome? Read the answers to all questions in our article.

What is the syndrome of inappropriate ADH secretion?

     Syndrome of improper secretion of ADH, or Parkhon's syndrome, antidiabetes insipidus, hyperpexic syndrome is a pathology that is manifested by excessive secretion of vasopressin. This secretion does not provide the proper osmolarity of the blood. This causes hyponatremia and fluid retention in the body.

Clinical picture. The increase in body weight and swelling are expressed slightly. The main symptom is impaired consciousness. The frequency and duration of impaired consciousness depends on the degree of decrease in sodium in the blood.

Normal concentration of sodium in the blood is 120-150 mmol/l

• When the sodium electrolyte content is less than 120 mmol/l, the patient feels a headache, body weight rapidly increases, despite the lack of appetite, nausea and vomiting. There is weakness in the muscles, drowsiness, depression, cramps and muscle spasms.
• When the sodium content is less than 110 mmol / l, this is manifested by confusion, psychosis. Tendon reflexes are reduced or absent altogether, disorientation in space. Body temperature drops, pseudobulbar paralysis is observed.
• If the sodium content in the blood decreases further, coma and death occur.

Causes of inappropriate vasopressin secretion syndrome

• Pathologies of the pulmonary system (pneumonia, aspergillosis, tuberculosis, sarcoidosis, empyema, bronchiolitis, bronchial asthma, lung abscess).
• CNS diseases (inflammatory diseases, surgical interventions, traumatic brain injury).
• Ectopic secretion of ADH (lymphosarcoma, mesothelioma, thymoma, prostate cancer, ureteral cancer and other cancers).
• Medications - vincristine, monoamine oxidase inhibitors, carbamazepine, neuroleptics, antidepressants, phenothiazines, lisinopril, cyclophosphamide, thiazide diuretics.
• Irreversible processes in the vasopressin type II receptor gene.

     With the secretion of vasopressin in large quantities, reabsorption in the kidneys becomes more intense. This causes hyponatremia and intoxication. The degree of hyponatremia and intoxication depends on the patient's fluid intake.

How to diagnose ADH inappropriate secretion syndrome?

Signs in blood and urine tests of this syndrome are as follows:

- blood osmolarity is less than urine osmolarity;

- sodium excretion by the kidneys is > 20 mmol/l;

- hyponatremia, decreased blood osmolarity;

- absence of edema, arterial hypotension and hypovolemia;.

- the function of the adrenal glands, kidneys and thyroid gland is within the normal range.

Differential diagnosis

     The syndrome of excessive secretion of vasopressin must be differentiated from some diseases in which hyponatremia is present. These are pseudohypernatremia, redistribution hypernatremia in DM, and hypervolemic hypernatremia.

     With pseudohypernatremia, the concentration of lipids and proteins in the blood plasma will still be increased. Redistribution hyponatremia occurs against the background of fluid loss through burn surfaces and the gastrointestinal tract, as well as after excessive parenteral fluid administration.

     To find out the reason for the low concentration of sodium in the blood, an empty stomach test is performed with a fluid load. The patient should be in a horizontal position. First, the osmolarity of urine and blood, the level of sodium in the blood, blood pressure, body weight, the presence of edema and the general well-being of the patient are determined. After that, the patient should drink ordinary water with a volume of 20 ml / kg, but not more than 1.5 liters, for 15-20 minutes. Also, the liquid can be administered intravenously - 0.9% sodium chloride solution. For 5 hours after drinking, the osmolarity of blood and urine, urine volume, blood pressure, body weight are measured every hour. Evaluate the presence of edema and well-being.

Criteria for the syndrome of inappropriate secretion of ADH:

• Urine osmolarity less than 100 mOsm/kg 2 hours after fluid administration.
• Highlight < 65% liquid after 4 hours.
• Display < 80% of water drunk after 5 hours.
• Reduced osmolarity and hyponatremia can be observed within a few hours.

     For a screening study, MRI is informative. It is advisable to do a CT scan of the chest and abdominal cavity in order to exclude oncological processes. Observation of renal function in dynamics will allow to identify the disease in time and assess the levels of osmolarity decrease.

Treatment of syndrome of inappropriate vasopressin secretion

     Therapy is aimed at normalizing osmolarity and sodium content in the blood. In an acute state, a 3% solution of sodium chloride is administered parenterally in combination with a diuretic. At the same time, it is important to control the rate of increase in the sodium content in the blood - it should be no more than 0.5-1.0 mmol / l. The infusion is stopped when a plasma sodium concentration of 125 mmol/L is reached. If the speed is higher, CNS damage is possible.

     People with this syndrome should be advised not to consume more than 1 liter of fluid per day. This will slow down the progression of the disease and somewhat alleviate the manifestation of the syndrome of increased secretion of vasopressin.

     Thus, if you see a person who has lost consciousness, advise him to take a blood test for electrolytes. This will rule out or confirm a hormonal disorder such as inappropriate ADH secretion syndrome, which is important to be aware of and to control.