Fainting

Fainting is a sudden loss of consciousness caused by transient ischemia of the brain.

Etiology, pathogenesis. The leading factor in the genesis of syncope is a decrease in blood pressure to a level at which autoregulatory mechanisms of cerebral circulation can not provide sufficient blood supply to the brain. There are 3 main pathogenetic links in the development of syncope: 1) the drop in blood pressure due to a decrease in peripheral vascular resistance in systemic vasodilation (psychogenic syncope caused by hyperactivity of the vagus nerve, orthostatic hypotension); 2) violation of the heart (Adams-Stokes-Morgani syndrome, aortic defects); 3) a decrease in the oxygen content in the blood (cardiopulmonary diseases).

Symptoms, course. Fainting begins with a feeling of faintness, ringing in the ears; Then a loss of consciousness follows. The patient slowly falls ("settles"), there is a sharp pallor of the skin. Pulse is small or not at all determined. Blood pressure is sharply reduced, breathing is superficial. The duration of loss of consciousness is 10-30 seconds. After fainting, general weakness, nausea, persists for some time. The most common variant of syncope is vagovasal; It is provoked by negative emotions and pain, stifling, kind of blood, a long standing, a sharp transition from a horizontal position to a vertical one. Rare fainting options are betotopepsia (fainting occurs at the height of a protracted fit of cough in patients with chronic lung diseases) and nocturnal fainting (more common in men, occurring after an act of urination at night or early in the morning).

Fainting must be differentiated from epileptic seizures, taking into account the possibility of epileptic seizures and the development of epileptiform seizures in severe syncope; The detection in the interictal period of epilepsy-specific changes in the electroencephalogram is the main diagnostic criterion. A hysterical attack differs from a syncope in the demonstrative nature of paroxysm and the onset of an attack only in the presence of outsiders. With prolonged fainting, it is necessary to examine the sugar content in the blood to exclude hypoglycemia.

Treatment. In the case of a vagovasal variant of fainting, medication is not required. It is necessary to lay the patient on his back and slightly raise his legs, to release the neck and chest from tight clothes. It is not necessary to seat the patients, as it is difficult to stop the cerebral ischemia underlying the fainting.

The prognosis of the relation of life is favorable. At the same time, it is rarely possible to significantly reduce the frequency of fainting of the vagovasal character, since their development is associated with a constitutional tendency to parasympathetic (vagal) reactions.