Anaphylaxis medical therapy
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1], Associate Editor(s)-in-Chief: Dushka Riaz, MD
Overview
Anaphylaxis is a medical emergency and requires prompt treatment as it can progress to fatal anaphylactic shock. Because it has variable diagnostic criteria that can carry an unpredictable course, the most important point of treatment is not to delay. Intramuscular epinephrine is the medication of choice and should be used promptly. Long-term management includes avoidance of triggers after confirmation for the cause from an allergist. Patients should be advised to carry self-injectable epinphrine in case of recurrent episodes. [1]
Medical Therapy
Emergency Treatment
Anaphylaxis is a life-threatening medical emergency because of rapid constriction of the airway, often within minutes of onset, which can lead to respiratory failure and respiratory arrest. Brain and organ damage rapidly occurs if the patient cannot breathe. Due to the severe nature of the emergency, patients experiencing or about to experience anaphylaxis require the help of advanced medical personnel. The first step is to remove the patient from exposure to the potential allergen. First aid measures for anaphylaxis include rescue breathing (part of CPR). Rescue breathing may be hindered by the constricted airways, but if the victim stops breathing on his or her own, it is the only way to get oxygen to him or her until professional help is available. [2] [3] [4] [5]
Another treatment for anaphylaxis is the administration of epinephrine (adrenaline). Epinephrine prevents worsening of the airway constriction, stimulates the heart to continue beating, and may be life-saving. Epinephrine acts on Beta-2 adrenergic receptors in the lung as a powerful bronchodilator (i.e. it opens the airways), relieving allergic or histamine-induced acute asthmatic attack or anaphylaxis. If the patient has previously been diagnosed with anaphylaxis, they may be carrying an EpiPen (or TWINJECT TM) for immediate administration of epinephrine. However, the use of an EpiPen or similar device only provides temporary and limited relief of symptoms. Tachycardia (rapid heartbeat) results from stimulation of Beta-1 adrenergic receptors of the heart increasing contractility (positive inotropic effect) and frequency (chronotropic effect) and thus cardiac output. [6] [7] [8] [9]
Repetitive administration of epinephrine can cause tachycardia and occasionally ventricular tachycardia with heart rates potentially reaching 240 beats per minute, which itself can be fatal. Extra doses of epinephrine can sometimes cause cardiac arrest. This is why some protocols advise intramuscular injection of only 0.3–0.5mL of a 1:1,000 dilution. Some patients with severe allergies routinely carry preloaded syringes containing epinephrine, diphenhydramine (Benadryl), and dexamethasone (Decadron) whenever they go to an unknown or uncontrolled environment. These three injections, taken at the beginning of anaphylaxis, can often bring it under control and avoid a trip to the emergency room. After administration of epinephrine, the patient should be placed supine and their vital signs should be monitored. If supplemental oxygen and intravenous fluid are indicated they should be administered. [10] [11] [1] [12]
Paramedic treatment in the field includes administration of epinephrine IM (or IV infusion in severe cases), Benadryl IM, steroids such as Decadron, IV Fluid administration and in severe cases, pressor agents (which cause the heart to increase its contraction strength) such as dopamine for hypotension, administration of oxygen, and intubation during transport to advanced medical care.
The clinical treatment of anaphylaxis by a doctor and in the hospital setting aims to treat the cellular hypersensitivity reaction as well as the symptoms. Antihistamine drugs such as Benadryl (which inhibit the effects of histamine at histamine receptors) are continued but are usually not sufficient in anaphylaxis, and high doses of intravenous corticosteroids such as Decadron or Solu-Medrol are often required. Hypotension is treated with intravenous fluids and sometimes vasopressor drugs. For bronchospasm, bronchodilator drugs (e.g. Salbutamol, known as Albuterol in the United States) are used. In severe cases, immediate treatment with epinephrine can be lifesaving. Supportive care with mechanical ventilation may be required.
It is also possible to undergo a second reaction prior to medical attention or using an epipen. It is suggested to seek one to two days of medical care.
The possibility of biphasic reactions (recurrence of anaphylaxis) requires that patients be monitored for four hours after being transported to medical care for anaphylaxis.
References
- ↑ 1.0 1.1 Alvarez-Perea A, Tanno LK, Baeza ML (2017). "How to manage anaphylaxis in primary care". Clin Transl Allergy. 7: 45. doi:10.1186/s13601-017-0182-7. PMC 5724339. PMID 29238519.
- ↑ Dhami S, Panesar SS, Roberts G, Muraro A, Worm M, Bilò MB; et al. (2014). "Management of anaphylaxis: a systematic review". Allergy. 69 (2): 168–75. doi:10.1111/all.12318. PMID 24251536.
- ↑ Simons FE, Ebisawa M, Sanchez-Borges M, Thong BY, Worm M, Tanno LK; et al. (2015). "2015 update of the evidence base: World Allergy Organization anaphylaxis guidelines". World Allergy Organ J. 8 (1): 32. doi:10.1186/s40413-015-0080-1. PMC 4625730. PMID 26525001.
- ↑ Simons FE (2010). "Anaphylaxis". J Allergy Clin Immunol. 125 (2 Suppl 2): S161–81. doi:10.1016/j.jaci.2009.12.981. PMID 20176258.
- ↑ Dhami S, Sheikh A, Muraro A, Roberts G, Halken S, Fernandez Rivas M; et al. (2017). "Quality indicators for the acute and long-term management of anaphylaxis: a systematic review". Clin Transl Allergy. 7: 15. doi:10.1186/s13601-017-0151-1. PMC 5442671. PMID 28546858.
- ↑ Sheikh A, Ten Broek V, Brown SG, Simons FE (2007). "H1-antihistamines for the treatment of anaphylaxis: Cochrane systematic review". Allergy. 62 (8): 830–7. doi:10.1111/j.1398-9995.2007.01435.x. PMID 17620060.
- ↑ Kemp SF, Lockey RF, Simons FE, World Allergy Organization ad hoc Committee on Epinephrine in Anaphylaxis (2008). "Epinephrine: the drug of choice for anaphylaxis. A statement of the World Allergy Organization". Allergy. 63 (8): 1061–70. doi:10.1111/j.1398-9995.2008.01733.x. PMID 18691308.
- ↑ McLean-Tooke AP, Bethune CA, Fay AC, Spickett GP (2003). "Adrenaline in the treatment of anaphylaxis: what is the evidence?". BMJ. 327 (7427): 1332–5. doi:10.1136/bmj.327.7427.1332. PMC 286326. PMID 14656845.
- ↑ Campbell RL, Bellolio MF, Knutson BD, Bellamkonda VR, Fedko MG, Nestler DM; et al. (2015). "Epinephrine in anaphylaxis: higher risk of cardiovascular complications and overdose after administration of intravenous bolus epinephrine compared with intramuscular epinephrine". J Allergy Clin Immunol Pract. 3 (1): 76–80. doi:10.1016/j.jaip.2014.06.007. PMID 25577622.
- ↑ Pumphrey RS (2003). "Fatal posture in anaphylactic shock". J Allergy Clin Immunol. 112 (2): 451–2. doi:10.1067/mai.2003.1614. PMID 12897756.
- ↑ Soar J, Pumphrey R, Cant A, Clarke S, Corbett A, Dawson P; et al. (2008). "Emergency treatment of anaphylactic reactions--guidelines for healthcare providers". Resuscitation. 77 (2): 157–69. doi:10.1016/j.resuscitation.2008.02.001. PMID 18358585.
- ↑ Muraro A, Roberts G, Worm M, Bilò MB, Brockow K, Fernández Rivas M; et al. (2014). "Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology". Allergy. 69 (8): 1026–45. doi:10.1111/all.12437. PMID 24909803.
Template:WikiDoc Sources CME Category::Cardiology
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Anaphylaxis Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Anaphylaxis medical therapy On the Web |
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American Roentgen Ray Society Images of Anaphylaxis medical therapy |
|
Risk calculators and risk factors for Anaphylaxis medical therapy |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [2]; Associate Editor(s)-in-Chief: