Anaphylactic shock

June 18, 2013

  

Anaphylactic shock is a severe allergic reaction with typical signs and symptoms. It can be caused by any foreign substance - foods, medications, insect bites, food additives and physical factors. Most common medications that can trigger anaphylaxis are β-lactam antibiotics (penicillin), NSAIDs, aspirin and topical anesthetics like articaine, mepivacaine and lidocaine. People with allergic diseases like asthma and rhinitis are at high risk of anaphylactic shock and should be tested before dental manipulations. That can happen by running an allergy test and determining the trigger.

The typical signs of anaphylaxis are paraesthesia, flushing and swelling of face, especially the areas around the eyelids and lips. Generalized urticatia is at place affecting mainly the hands and feet. There is a rapid weak pulse, drop in the blood pressure, wheezing and difficulty in breathing.

The anaphylactic shock can develop really fast - from 15 to 30 minutes following the oral administration of a drug or rapidly after topical or i.v. drug administration. Avoidance of the trigger is strongly recommended. In the anamnesis the dentist should ask about past allergic reactions or any allergies known. If there had been some reactions in the past an allergy testing should be performed - skin allergy testing (scratch or patch testing) or blood testing for specific IgE antibodies.

Differential diagnosis of anaphylactic shock

The anaphylaxis  should be distinguished from panic attack, asthma and syncope. There are several sign of these conditions which can lead you to the right diagnosis. Asthma, for example, does not include itching and the typical gastrointestinal symptoms. The panic attacks are associated with flushing but do not include generalized urticaria. Syncope presents with pallor rather than hives or flushing.

 
What should the dentist do when the patient is developing an anaphylactic shock

- lay the patient flat with feet above head level - Trendelenburg position
- give oxygen
- give 0,5 ml epinephrine (adrenaline) 1mg/ml (1 in 1000) intramuscular - 0.25 ml for 6-12 years and 0.12 ml for 6 months to 6 years
- Chlorphenamine (chlorpheniramine) 10 mg in 1 ml intramuscular or slow i.v. injection
- Hydrocortisone sodium succinate 200 mg by slow i.v.
- Fluids i.v. (colloids) infused rapidly if shock not responding quickly to adrenaline injection

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