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Anaphylaxis

Written on 16/11/2024
tok.ilman609
2

Diagnosis:
Anaphylaxis is characterized by an acute onset of illness with mucocutaneous involvement and at least ONE of the following:

i. Respiratory symptoms:

  • Wheezing, stridor, dyspnea, throat tightness.

ii. Hypotension:

  • Systolic blood pressure <90 mmHg or a >30% drop from baseline.

iii. Gastrointestinal disturbances:

  • Abdominal pain, vomiting, diarrhea.

 

1. Rapid Clinical Assessment & Stabilization

  • ABCDE approach
  • High-Flow Oxygen (HFMO₂):
    • Administer at 15 L/min to maintain adequate oxygen saturation.

 

 

2. Adrenaline Administration:

Adult Dose:

Adrenaline 0.5 mL (0.5 mg) of 1:1000 solution IM injected into the mid-lateral thigh.

 

This may be repeated up to 3 times every 5 minutes if symptoms persist.

 

Pediatric Dosing:

>12 years: 0.5 mg

6-12 years: 0.3 mg

<6 years: 0.15 mg

 

If no improvement after 3 doses, consider IV adrenaline infusion:

  • 3 mg diluted in 47 mL of normal saline (NS)
  • Run continuous infusion at 0.1 mcg/kg/min using an infusion pump.

 

If an infusion pump is not available,

  • Dilute 0.5 mg in 500 mL NS.
  • Start the infusion at 2 mL/min,
    • Titrating up to 10 mL/min based on the patient's response.

 

 

3. Special Considerations:

Patients on Beta-Blockers they may not respond effectively to adrenaline.

Glucagon (1-5 mg over 5 minutes) IV

Followed by an infusion at 5-15 mcg/min if necessary.

 

 

4. Bronchodilator Therapy:

Administer MDI or nebulized salbutamol if bronchospasm is present.

 

Note: Be prepared for potential intubation if there is impending airway obstruction due to angioedema.

 

 

5. Adjunctive Therapy:

i. H1 Antagonist:

  • Chlorphenamine (Piriton) 10 mg IV

ii. H2 Antagonist:

  • Ranitidine 50 mg IV

iii. Corticosteroid:

  • Hydrocortisone 200 mg IV
    • To help reduce inflammation and prevent biphasic reactions.

 

 

References:
  1. American College of Allergy, Asthma, and Immunology. (2020). Anaphylaxis: Guidelines for emergency management.
  2. Simons, F. E. R., Ardusso, L. R. F., Bilò, M. B., El-Gamal, Y. M., Ledford, D. K., Ring, J., ... & World Allergy Organization. (2011). World Allergy Organization anaphylaxis guidelines: Summary. The Journal of Allergy and Clinical Immunology, 127(3), 587–593. https://doi.org/10.1016/j.jaci.2010.11.020
  3. Lieberman, P., Nicklas, R. A., Randolph, C., Oppenheimer, J., Bernstein, D., Bernstein, J., ... & Kemp, S. F. (2015). Anaphylaxis—a practice parameter update 2015. Annals of Allergy, Asthma & Immunology, 115(5), 341–384. https://doi.org/10.1016/j.anai.2015.07.019
  4. Sheikh, A., Shehata, Y. A., Brown, S. G., & Simons, F. E. (2009). Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock. Cochrane Database of Systematic Reviews, (4). https://doi.org/10.1002/14651858.CD006312.pub2
  5. Kemp, S. F., Lockey, R. F., Simons, F. E., & Epinephrine in Anaphylaxis Study Group. (2008). Epinephrine: The drug of choice for anaphylaxis. A statement of the World Allergy Organization. Allergy, 63(8), 1061–1070. https://doi.org/10.1111/j.1398-9995.2008.01733.x
  6. Brown, S. G. A. (2004). Clinical features and severity grading of anaphylaxis. The Journal of Allergy and Clinical Immunology, 114(2), 371–376. https://doi.org/10.1016/j.jaci.2004.04.029

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