What is Anaphylactic Shock?

Anaphylactic shock is a severe systemic allergic reaction triggered by immune mechanisms within a short period of time after certain external antigenic substances enter the sensitized body. They often occur suddenly and have severe severity. If not treated in time, Often life-threatening. Insect stabbing and taking certain medicines (especially penicillin-containing medicines) are the most common causes of anaphylactic shock. Certain foods (such as peanuts, shellfish, eggs, and milk) can also cause severe allergic reactions.

Basic Information

Visiting department

Emergency Department

Common causes

Caused by some external antigenic substances entering the sensitized body

Common symptoms

Skin flushing, itching, edema of the throat, sweating, pale, weak pulse speed, damp and cold limbs, cyanosis, etc.

Causes of anaphylactic shock

The vast majority of anaphylactic shock is a type I allergy. The entry of external antigenic substances (some drugs are incomplete antigens, which are combined with proteins to become full antigens after entering the human body) can stimulate the immune system to produce corresponding IgE antibodies. The production of IgE varies greatly depending on the constitution. These specific IgEs have strong cell-like properties and can bind to "target cells" such as skin, bronchus, and vessel walls. Thereafter, when the same antigen substance comes into contact with the sensitized organism again, a wide range of type allergies can be stimulated. Among them, histamine and platelet activating factors released by various inflammatory cells are the main causes of edema and exudation of tissues and organs. Biologically active substances.

Clinical manifestations of anaphylactic shock

The performance and severity of anaphylactic shock vary greatly depending on the body's reactivity, the amount of antigen entry, and pathways. Most of the diseases occur suddenly. About half of the patients develop symptoms within 5 minutes after receiving the causative antigen (such as penicillin G injection). Only 10% of the patients' symptoms start after half an hour, and very few patients appear during the continuous medication.

There are two major characteristics of anaphylactic shock: one is the performance of shock, sweating, pale, weak pulse speed, damp and cold limbs, irritability, unconsciousness or complete loss, rapid drop in blood pressure or even undetectable, pulse disappears , Which eventually leads to cardiac arrest; the second is accompanied by some allergy-related symptoms before or at the same time as shock.

1. Skin and mucosal manifestations

It is often one of the earliest and most common symptoms of anaphylactic shock, including flushing of the skin, itching, and then widespread urticaria and / or angioedema; sneezing, watery nose, and hoarseness can also occur.

2. Symptoms of airway obstruction

Laryngeal edema, and / or bronchospasm (asthma) are common manifestations of this disease and one of the leading causes of death. The patient developed a feeling of blocked throat, chest tightness, shortness of breath, wheezing, belching, cyanosis, and died of suffocation.

3. Other symptoms

More common are irritating cough, continuous sneezing, nausea, vomiting, abdominal pain, diarrhea, and severe incontinence can occur.

Anaphylactic shock diagnosis

The disease occurs quickly, so a diagnosis must be made in a timely manner. When a systemic reaction occurs immediately after receiving (especially after injection) an antigenic substance or a drug, or a bee bite, and it is difficult to explain the pharmacological effects of the drug itself, the possibility of the disease should be immediately considered.

Anaphylactic shock treatment

Death from anaphylactic shock can occur within minutes, and it is important to deal with it quickly. The key to starting treatment is to keep the airway open and maintain effective breathing and circulation.

1. Immediately stop entering and remove suspected allergens or pathogenic drugs.

2. Make sure the patient's airway is open and give oxygen. If a life-threatening airway obstruction occurs, immediately intubate or open the bedside trachea.

3. Immediately give epinephrine, 0.01 mg / kg in children, the maximum dose of 0.5 mg / time, subcutaneous injection, repeat every 15 minutes if necessary; 0.5 mg for adults, subcutaneous or intramuscular injection, repeat as appropriate. Epinephrine can rapidly relax bronchospasm through the -receptor effect and contract small peripheral blood vessels through the -receptor effect; it can also counteract the release of some type I allergic mediators, so it is the drug of choice for the treatment of this disease. If hypotension occurs or there is no response to the initial epinephrine dose, 1: 1 000 epinephrine is administered intravenously, and physiological saline 20 ml / kg is administered. If hypotension persists, epinephrine or dopamine is administered intravenously.

4. Glucocorticoid, the course of treatment does not exceed 3 to 5 days, or dexamethasone, diluted with 5% glucose injection intravenously, usually for 1 to 3 days.

5. Salbutamol dilates the bronchi and inhales adrenaline to treat asthma.

6. Anti-allergy and symptomatic treatment, commonly used chlorpheniramine or promethazine.

7. Monitor vital signs for a minimum of 24 hours. Serious clinical manifestations require hospitalization.