Anaphylaxis (Medical students)
Clinical Signs
- Airway: stridor and respiratory failure from laryngeal oedema.
- Breathing: respiratory failure from bronchospasm.
- Circulation: shock from vasodilatation and capillary leak, clinically evident from a decreased level of consciousness, tachycardia and (late sign) hypotension.
- Skin: flushing, urticaria, pallor.
Management
- Secure Airway and 100% oxygen. Intubation and ventilation if in respiratory failure. Pulse oximetry.
- Adrenaline 1:1000 0.01ml/kg IM (not subcutaneously) is the first-line treatment (do not waste time on other drugs). Repeat adrenaline every 5 minutes if there is inadequate clinical improvement.Consider Adrenaline infusion 0.1 mg/kg/min for persistent, serious reaction.
- Fluid bolus Normal saline 20ml/kg (IV/IO) if clinical shock (drowsiness, tachycardia, hypotension). Place the patient in a recumbent position with the lower extremities elevated.
- Adjunctive treatment: consider bronchodilators (salbutamol), H1 antagonist (antihistamine) Chlorpherinamine “Piriton” and H2 antagonist (Cimetidine or Ranitidine) and hydrocortisone.
Observe for several hours when stable.