Anaphylaxis Shock Resuscitation in Pediatric

Anaphylaxis is a potentially life-threatening systemic allergic reaction mediated by IgE antibody, resulting in the release of histamine, leukotrienes and vasoactive mediators. The commonest etiologies are specific environmental allergens, e.g. food, insect bites, drugs, blood products and radiocontrast media. Most reactions occur within 30 minutes of exposure and require prompt assessment and aggressive treatment. 

Signs and symptoms

A prodrome of flushing, facial swelling, urticaria, wheeze and stridor may precede airway obstruction or shock.

Life-threatening features of anaphylaxis and their cause:

Feature Cause  ---> Stridor Laryngeal and pharyngeal edema (tongue, lips and uvula)

Cough and wheeze --->  Bronchospasm

Hypotension  ---> Systemic vasodilatation and hypovolemia (capillary leak)

The child may also have pruritis, nausea, vomiting, abdominal cramps and diarrhea. 

Immediate management

Epinephrine (adrenaline) and the ABC approach are the mainstays of treatment.

Epinephrine

Give epinephrine (adrenaline) s.c. i.m. (0.01 ml kg−1 of 1:1000) or slowly i.v. (0.1 ml kg−1 of 1:10000)

Improvement should be seen within 2 minutes. The dose of epinephrine (adrenaline) should be repeated if the effect is incomplete.

Airway/breathing

The child should be given:

• oxygen by facemask

• nebulized epinephrine (adrenaline) 5 ml of 1/1000 may be used in conjunction with intravenous epinephrine, or alone for mild upper airway obstruction

• intubation if airway obstruction is severe

Call for urgent anesthetic and ENT assistance as the child may need urgent intubation and, very rarely, a surgical airway.

Circulation

Intravenous access should be secured with a wide bore cannula. Circulation should then be supported.

• Give 20 ml kg−1 of normal saline, for hypotension.

• If hypotension continues, give further fluid bolus of 20 ml kg−1 and not colloid doses and repeat epinephrine (adrenaline) dose every 5 minutes or consider i.v. epinephrine (adrenaline) infusion 0.1 µg kg−1 min−1 with the child on continuous oxygen saturation, ECG and BP monitoring. Senior emergency and intensive care staff should be called.

Further management

All patients with anaphylaxis should be admitted for observation as they may deteriorate after the initial episode. They may need further treatment, including:

• steroids: hydrocortisone 4 mg kg−1.