Acute anaphylaxis

Description:

Acute anaphylaxis mean the acute system allergic reaction involving more than one body on repeated contact with allergen by the name. Often acute anaphylaxis threatens life as a result of the expressed pressure drop and possible development of suffocation. Anaphylactic shock is the most dangerous complication of a medicinal allergy, coming to an end approximately in 10-20% of cases letalno. Speed of emergence of an acute anaphylaxis — of several seconds or minutes till 2 o'clock from the beginning of contact with allergen. In development of anaphylactic reaction in patients with high degree of a sensitization neither the dose, nor a way of administration of allergen play a crucial role. However there is a certain correlation: the high dose of drug increases weight and duration of a current of shock.
On the pathogenetic mechanism of development the acute anaphylaxis is allergic reaction of the 1st type (immediate type) which is caused by immunoglobulin E.

Reasons of the Acute anaphylaxis:

The acute anaphylaxis can arise at influence of any antigen. It is observed at therapeutic and diagnostic interventions — use of drugs (penicillin and its analogs, streptomycin, B1 vitamin, pyramidon, analginum, novocaine), immune serums, iodinated radiopaque substances, at cutaneous testing and performing the hyposensibilizing therapy by means of allergens, at errors of hemotransfusion, blood substitutes, etc.

Pathogeny of the Acute anaphylaxis:

The acute anaphylaxis is allergic reaction of immediate type - the 1st type. The phenomenon of linkng of an allrgen with mast cells which are located closer to blood vessels, and the basophiles circulating in blood is its cornerstone. There is a reaction of interaction between the allergen which got to an organism and immunoglobulin E therefore from corpulent klet the histamine, an inflammation mediator vysvobodzhatsya. As a result of action of a histamine, and also prostaglandins and leukotrienes, there is an increase in permeability of a vascular wall, a spasm of bronchioles, slime hypersecretion, and also an exit of a liquid part of blood (plasma) in an intercellular prostaranstvo. Pathological action of a histamine is resulted by sharp increase in capacity of a vascular bed and sharp reduction VCB (the volume of the circulating blood), pressure decreases, and it in turn leads to reduction of venous return of blood to heart and reduction of a stroke output of heart.

Symptoms of the Acute anaphylaxis:

Traditionally in a clinical picture of an acute anaphylaxis allocate 3 forms:
1. The prompt form comes in 1-2 seconds after introduction of an allrgen. There is a loss of consciousness, spasms, expansion of pupils (miosis), lack of reaction of pupils not light. Arterial pressure decreases, breath is broken, cardiac sounds are not listened. Death at this form comes in 8-10 minutes
2. The severe form arises in 5-7 minutes after an allergen vvedeneiya. The feeling of heat, breath disturbance, expansion of pupils is characteristic. The headache disturbs, falling of arterial pressure is observed.
3. The average form of an acute anaphylaxis develops in 30 minutes after administration of allergen. Allergic rash on skin, a skin itch takes place.
The following options are characteristic of an average form:
A. Cardiogenic with a fluid lungs
B. Astmopodobny with a bronchospasm, a laryngospasm, throat hypostasis.
B. Cerebral of which psychomotor arousing, disturbance of consciousness, a spasm is characteristic.
G. Abdominal with simptomaty "acute abdomen".

The reasons of a lethal outcome at an acute anaphylaxis:
1. Acute heart and respiratory failure
2. Acute renal failure
3. Brain hypostasis
4. Hemorrhage in a brain, adrenal glands.

Differential diagnosis:

Symptom of an acute anaphylaxis is emergence at once after administration of drug or during its introduction of the general weakness, a severe headache, an acute pain behind a breast, abdominal pain, pallor mucous and integuments. To distinguish the beginning of development of nafilaktichesky shock from a loss of consciousness, it is necessary to remember that at an acute anaphylaxis in the beginning consciousness remains and tachycardia is observed. Perhaps bystry emergence of a Quincke's edema, bronchospasm and respiratory insufficiency. There is skin cyanosis, an asthma. The patient is uneasy, complains of an itch. As a result of arterial hypotension and a renal failure there can come death.

Treatment of the Acute anaphylaxis:

Algorithm of delivery of health care at an acute anaphylaxis.
1. To stop intake of allergen in an organism:
- to suck away the entered solution the syringe, to make a section (for the anesthetics entered infiltrative), to wash out an oral cavity (for elimination of medicines), to impose a plait (if the drug was administered in a hand or in a leg).
- near an uchatka of an injection of drug to infiltrirovat skin and hypodermic cellulose of 0,5 ml of 1% of solution of adrenaline, divorced 5 ml of normal saline solution.
- to enter a penicillinase if anaphylactic shock arose against the background of introduction of an apenitsillin.
2. To enter at the same time:
- adrenaline of 0,3-0,5 ml п / to
- 5-10 mg/min. intravenously to repeat 2 times in 5 minutes, or 0,1 mg in 10 ml of isotonic solution in an endotracheal tube
- to intravenously pour in glucocorticoids and antihistamines
- a hydrocortisone of 15-3000 mg, either Prednisolonum of 1000 mg, or dexamethasone of 4-20 mg in 10-15 ml of 5% or 40% of a glyukozyvvesta of Dimedrol of 1%, or Suprastinum of 2% or Pipolphenum of 2,5% in 2-3 ml in oil or in/in
3. If allergen got through a stomach the gastric lavage and intestines, enterosorbents is shown (absorbent carbon, энтеросгель), at the same time carry out a trachea intubation at all options and forms of shock, except abdominal, carry out catheterization of a bladder and enter the probe into a stomach through nasal the course.
4. At the same time enter an Euphyllinum of 8 mg/kg an hour.
5. At inefficiency - a plasma exchange, an oksigenterapiya.
6. At development of cardiopulmonary insufficiency - the relevant resuscitation activities.
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Prevention:

The prevention of development of an acute anaphylaxis consists, first of all, in full collecting the allergological anamnesis including hereditary (existence of associated diseases - atopic dermatitis, bronchial asthma, a small tortoiseshell, a Quincke's edema on medicines and products, at children is definition of the allergological anamnesis of parents). It is necessary to find out information on the previous administration of drug which the doctor intends to apply effects of its use. Now there are reasonable cautions on carrying out allergy tests on sensitivity to drugs which can sensibilize an organism or cause an anaphylaxis. At smaller suspicions of development of anaphylactic reaction it is necessary to use the general anesthesia. At patients with the allergological anamnesis dental interventions are carried out in the conditions of a hospital after preliminary administration of the desensibilizing drugs.