Ch 21 - Allergic reactions and anaphylaxis

What is an allergic reaction?

An exxagerated immune response to any substance

Which chemicals contribute to allergic reactions?

Histamines and leukotrienes

Urticaria

Widespread hives

Angioedema

Areas of localized swelling

Wheezing vs Stridor

Wheezing is heard on expiration and is swelling of the lower airway, stridor is heard on inspiration and is swelling of the upper airway

Signs and symptoms of insect stings and bites

• Sudden pain

• Swelling

• Localized heat

• Wheal

How does epinephrine help anaphylaxis?

It reverses vasodilation and hypotension, elevates BP and improves coronary blood flow

Adult EpiPen dose

Child EpiPen dose

0.3 mg

0.15 mg

Where should an epipen be administered on the body of the patient?

Against the lateral part of the thigh

Side effects of epinephrine

• Increased BP

• Increase pulse

• Anxiety

• Cardiac dysrhythmias

• Dizziness

• Chest pain

When does an allergic reaction turn into anaphylaxis?

When it starts to compromise the respiratory and cardiac system

Common allergens

• Plants; dust, pollen

• Chemicals; makeup, soap

• Insect bites/stings

Signs of a severe anaphylactic event

• Stridor

• Bronchospasm/wheezing

• Chest tightness

• Dsypnea

• Anxiety

• Hypotension

• Gastrointestinal complaints

What to look for during the primary assessment for anaphylaxis/allergic reactions

Look for:

• Increased work of breathing

• Tripod position

• Abnormal breath sounds

How to assist a patient in anaphylactic reaction

• Assist patient to fowler position

• High-flow O2

• Place in supine position if there are signs of shock

When is epinephrine allowed to be used?

Two or more body systems need to be affected

What causes the symptoms associated with an allergic reaction?

Histamines and leukotrienes

What is the most common trigger of anaphylaxis?

Food

How long should an EpiPen be held in place?

10 sec