Why does epinephrine help in anaphylaxis

However, none of these circumstances pose an absolute contraindication to epinephrine administration for anaphylaxis[ 13 ]. Physician and other health care professionals who perform procedures or administer medications should have available the basic therapeutic agents used to treat anaphylaxis [ 4 , 7 , 13 ] : 1 stethoscope and sphygmomanometer; 2 tourniquets, syringes, hypodermic needles, large-bore needles eg, or gauge ; 3 injectable aqueous epinephrine 1 mg in 1 mL; physicians are being urged to express doses in mass concentration, eg, 1 mg in mL, rather than as ratios, eg, , which have been identified as a source of dosing errors with epinephrine and other medications ; 4 equipment and supplies for administering supplemental oxygen; 5 equipment and supplies for administering intravenous fluids; 6 oral or laryngeal mask airway; 7 diphenhydramine or similar injectable antihistamine; 8 ranitidine or other injectable H2 antihistamine; 9 corticosteroids for intravenous injection; and 10 vasopressors eg, dopamine or norepinephrine.

Glucagon, an automatic defibrillator, and 1-way valve face mask with oxygen inlet port are other supplies that some clinicians might find desirable depending on the individual clinical setting[ 13 ].

Assessment and maintenance of airway, breathing, circulation, and mentation are necessary before proceeding to other management steps. Patients are monitored continuously to facilitate prompt detection of any clinical changes or treatment complications.

Placement of a patient in the recumbent position with elevation of the lower extremities is strongly recommended because management in the sitting or upright position has contributed to poor outcomes in some patients[ 34 ]. Epinephrine should be administered simultaneously with the above measures[ 12 - 14 ].

By expert consensus based on anecdotal evidence, there is no absolute contraindication to epinephrine administration in anaphylaxis[ 13 ]. It can be administered in doses appropriate for the severity of the reaction, regardless of the initial signs and symptoms of anaphylaxis.

All subsequent therapeutic interventions depend on the initial response to epinephrine. Development of toxicity or inadequate response to epinephrine injections indicates that additional therapeutic modalities are necessary[ 13 ].

Modalities used in concert with epinephrine are reviewed in detail elsewhere[ 10 - 14 ]. Adapted from Lieberman et al. Expert consensus and anecdotal evidence indicate aqueous epinephrine dilution 1 mg in 1 mL , 0. Efficacy comparisons of intramuscular injections to subcutaneous injections have not been done during acute anaphylaxis. However, absorption is complete and more rapid and plasma levels are higher in asymptomatic adults and children who receive epinephrine intramuscularly in the anterolateral thigh vastus lateralis [ 60 , 61 ].

In overweight and obese individuals, the thickness of the subcutaneous fat pad may preclude intramuscular access[ 62 - 64 ]. Anaphylaxis occurs as part of a continuum, and delaying treatment until multiorgan dysfunction is present is risky.

The recommendations in this table apply regardless of comorbid conditions because there is no absolute contraindication to epinephrine administration during anaphylaxis. Physicians and other health care professionals should instruct patients at risk for anaphylaxis outside of a medical facility to err on the side of caution and self-administer epinephrine if there is any doubt anaphylaxis is either present or imminent.

Adapted from Sicherer and Simons[ 65 ]. Epinephrine autoinjectors, which are easy to use and will inject through clothing, are currently available in 2 fixed doses: 0.

The potential exists for overdosage in infants receiving the 0. The relative benefits and risks of dosage might vary with each individual, but autoinjectors with 0. Providing parents with an epinephrine ampule, syringe, and needle is not an appropriate option unless autoinjectors are not available for prescription[ 66 ]. Epinephrine , or , dilutions should be administered by infusion during cardiac arrest or to unresponsive or severely hypotensive patients who have failed to respond to intravenous volume replacement and several epinephrine injections[ 13 ].

One group of investigators suggest that the early use of intravenous epinephrine is safe, effective, and well tolerated when the rate is titrated to clinical response, but this has not been evaluated systematically in a cohort study comparing this modality to epinephrine intramuscular injections[ 67 ]. Some physicians recommend inhalation of epinephrine as an alternative to injection during anaphylaxis, but perioral paresthesias, bad taste, and gastrointestinal effects are dose-limiting, and it may not achieve prompt significant increases in plasma epinephrine concentrations[ 68 , 69 ].

No direct comparisons have been made between the inhaled and the intramuscular routes of epinephrine administration. Observation periods should be individualized and based on such factors as comorbid conditions and distance from the patient's home to the closest emergency facility, particularly because there are no reliable predictors of biphasic anaphylaxis[ 13 ].

After resolution of the acute episode, patients should be discharged with an epinephrine autoinjector and properly instructed on how to self-administer it in case of a subsequent episode.

They should receive an individualized Anaphylaxis Emergency Action Plan[ 18 ]. Patients should also have ready access to emergency medical services to facilitate prompt transportation to the closest emergency department ED for treatment after injecting the additional epinephrine.

Numerous guidelines on anaphylaxis have been published, but physicians and other health care professionals often do not follow them. Retrospective analysis of a national reporting database on ED visits in the United States from to revealed Anaphylaxis coding was rare 0. Primary care physicians have demonstrated similar knowledge gaps in their knowledge pertaining to anaphylaxis. For example, a questionnaire based on the clinical scenario of a child with peanut-induced anaphylaxis was used in a random sample of pediatricians in the United States[ 74 ].

Similar surveys have been done in other countries several studies are cited in Pongracic and Kim[ 75 ]. Studies have also demonstrated that many health care professionals are uncertain about how to use an epinephrine autoinjector and thus cannot properly instruct their patients[ 76 , 77 ]. Available resources may help physicians develop treatment plans and resolve any therapeutic quandaries[ 17 , 18 , 65 ]. Examples of written action plans can be downloaded over the Internet see Additional Educational Resources.

Fatalities during witnessed anaphylaxis, most of which occur outside of a medical facility, usually result from delayed administration of epinephrine. In a retrospective review of 6 fatal and 7 nonfatal episodes of food-induced anaphylaxis in children and adolescents, all subjects who survived had received epinephrine before or within 5 minutes of developing severe respiratory symptoms.

None of the subjects with fatal attacks received epinephrine before the onset of severe respiratory symptoms[ 20 ]. Multiple factors may contribute to the lack of available epinephrine for administration during anaphylaxis that occurs outside of a medical facility. An international survey conducted under the auspices of the World Allergy Organization determined that epinephrine autoinjectors were available in about half of surveyed countries, and that the cost of an autoinjector in some countries was equivalent to the monthly salary of an average citizen[ 78 ].

Of 39 countries, autoinjectors containing 0. Adherence to an action plan to keep epinephrine available at all times and to inject it during anaphylaxis is another concern. Still others carry epinephrine but choose not to use it during anaphylaxis[ 32 , 85 - 87 ] or prefer to seek emergency medical assistance[ 21 ]. Few studies thus far have examined management of anaphylaxis in school or day care settings.

These are reviewed in detail elsewhere[ 75 ]. Protection of children at risk for anaphylaxis in school, day care, or other settings requires an interdisciplinary approach[ 9 ]. Several resources are available for help in the school or day care setting see Additional Educational Resources. All patients at risk for future anaphylaxis should carry at least 1 epinephrine syringe and know how to administer it.

Based on available evidence, the benefit of using appropriate doses of intramuscular epinephrine in anaphylaxis far exceeds the risk evidence category IV.

Consensus opinion and anecdotal evidence recommend epinephrine administration "sooner rather than later," that is, when the initial signs and symptoms of anaphylaxis occur, regardless of their severity, because fatalities in anaphylaxis usually result from delayed or inadequate administration of epinephrine.

Experts may differ on how they define the clinical threshold by which they define and treat anaphylaxis. However, they have no disagreement whatsoever that appropriate doses of intramuscular epinephrine should be administered rapidly once that threshold is reached.

There is no absolute contra-indication to epinephrine administration in anaphylaxis, and all subsequent therapeutic interventions depend on the initial response to epinephrine. Development of toxicity or inadequate response to epinephrine injections indicates that additional therapeutic modalities are necessary. All individuals at increased risk of anaphylaxis should have an anaphylaxis action plan and carry epinephrine autoinjectors for self-administration.

Such individuals and their caregivers, as appropriate should be assessed regularly for adherence with these recommendations and for the ability to demonstrate proper epinephrine administration technique with a placebo device.

This article was originally published in Allergy. Epinephrine: the drug of choice for anaphylaxis. Allergy ;Y National Center for Biotechnology Information , U.

World Allergy Organ J. Published online Jul Author information Article notes Copyright and License information Disclaimer. Corresponding author. Richard F Lockey: ude. This article has been cited by other articles in PMC. Abstract Anaphylaxis is an acute and potentially lethal multisystem allergic reaction. Keywords: anaphylaxis, epinephrine, management, prevention.

Definition The traditional nomenclature for anaphylaxis reserves the term anaphylactic for immunoglobulin E IgE -dependent reactions and the term anaphylactoid for IgE-independent events, which are clinically indistinguishable. Methods A literature search of Medline to present was conducted using the key words anaphylaxis and epinephrine and articles from the personal anaphylaxis file collections of the authors were also included.

Open in a separate window. Figure 1. Figure 2. Figure 3. Management of Anaphylaxis Physician and other health care professionals who perform procedures or administer medications should have available the basic therapeutic agents used to treat anaphylaxis [ 4 , 7 , 13 ] : 1 stethoscope and sphygmomanometer; 2 tourniquets, syringes, hypodermic needles, large-bore needles eg, or gauge ; 3 injectable aqueous epinephrine 1 mg in 1 mL; physicians are being urged to express doses in mass concentration, eg, 1 mg in mL, rather than as ratios, eg, , which have been identified as a source of dosing errors with epinephrine and other medications ; 4 equipment and supplies for administering supplemental oxygen; 5 equipment and supplies for administering intravenous fluids; 6 oral or laryngeal mask airway; 7 diphenhydramine or similar injectable antihistamine; 8 ranitidine or other injectable H2 antihistamine; 9 corticosteroids for intravenous injection; and 10 vasopressors eg, dopamine or norepinephrine.

When to Administer Epinephrine Epinephrine should be administered simultaneously with the above measures[ 12 - 14 ]. Table 1 Management of Acute Anaphylaxis. Administer epinephrine intramuscularly every 5 to 15 minutes, in appropriate doses, as necessary, depending on the presenting signs and symptoms of anaphylaxis, to control signs and symptoms and prevent progression to more severe symptoms, such as respiratory distress, hypotension, shock, and unconsciousness. Isotonic sodium chloride solution intravenously for fluid replacement III.

For cardiopulmonary arrest during anaphylaxis, high-dose epinephrine and prolonged resuscitation efforts are encouraged, if necessary see reference for specific details. Epinephrine Injections Expert consensus and anecdotal evidence indicate aqueous epinephrine dilution 1 mg in 1 mL , 0. Generalized urticaria develops in a yr-old fire ant-allergic individual stung by ant while playing in the yard. Pro: inject immediately; past anaphylaxis and current findings away from medical facility Con: do not inject immediately; wait for symptoms involving another organ system A yr-old yellow jacket-allergic farmer has just been stung after disturbing nest with tractor.

History of hypotension and rapid syncope in past stings. Currently receives venom immunotherapy but is not yet at maintenance last dose was 1 mL [L]. No current symptoms. Pro: inject immediately in view of past severe anaphylaxis; low risk of serious side effects from injected epinephrine; some risk of severe symptoms because he has not reached maintenance Con: do not inject immediately; wait for symptoms A yr-old individual develops paroxysmal sneezing within 5 min of receiving allergen immunotherapy injection Pro: inject immediately; rapid onset of symptoms may be associated with severe anaphylaxis; low risk of serious side effects from injected epinephrine; antihistamines are second-line agents in anaphylaxis Con: do not inject immediately; wait for other symptoms if suspect sneezing could be due to transient respiratory irritant exposure or seasonal allergy exacerbation if it occurs during pollen season of a pollen-allergic individual.

A 7-yr-old child with mild persistent asthma and clinical history of peanut allergy wheeze, hives that "get better after vomiting" experiences sudden cough and wheeze while playing outside 15 min after eating a cookie in school cafeteria; has no other symptoms; has albuterol metered-dose inhaler and epinephrine autoinjector available Pro: inject immediately; history is strongly suggestive of past anaphylaxis; safety of cookie is uncertain; signs and severity of anaphylaxis can vary from episode to episode in the same individual; delayed treatment or treating anaphylaxis with salbutamol albuterol alone could have adverse outcome; low risk of serious side effects from injected epinephrine Con: do not inject immediately; for possible asthma eg, exercise-induced or pollen exposure , assess response to salbutamol first.

Intravenous Epinephrine Epinephrine , or , dilutions should be administered by infusion during cardiac arrest or to unresponsive or severely hypotensive patients who have failed to respond to intravenous volume replacement and several epinephrine injections[ 13 ]. Inhaled Epinephrine Some physicians recommend inhalation of epinephrine as an alternative to injection during anaphylaxis, but perioral paresthesias, bad taste, and gastrointestinal effects are dose-limiting, and it may not achieve prompt significant increases in plasma epinephrine concentrations[ 68 , 69 ].

Follow-Up and Observation after Anaphylaxis Observation periods should be individualized and based on such factors as comorbid conditions and distance from the patient's home to the closest emergency facility, particularly because there are no reliable predictors of biphasic anaphylaxis[ 13 ]. Use of Epinephrine by Health Care Professionals Numerous guidelines on anaphylaxis have been published, but physicians and other health care professionals often do not follow them.

Underutilization of Epinephrine by Patients, Parents, and Caregivers Fatalities during witnessed anaphylaxis, most of which occur outside of a medical facility, usually result from delayed administration of epinephrine. Modified from Kemp[ 88 ]. Conclusions Based on available evidence, the benefit of using appropriate doses of intramuscular epinephrine in anaphylaxis far exceeds the risk evidence category IV.

Acknowledgements This article was originally published in Allergy. Emergency treatment of insect sting allergy. J Allergy Clin Immunol.

The use of epinephrine in the treatment of anaphylaxis. Position statement. Guidelines to minimize the risk from systemic reactions caused by immunotherapy with allergenic extracts. Chad ZH. Dean JM. Fatal anaphylactic reactions to food in children. Can Med Assoc J. The diagnosis and management of anaphylaxis. Lockey RF. Malling H-J. World Health Organization Position Paper.

Allergen immunotherapy: therapeutic vaccines for allergic diseases. Sedana A. Metcalf S. Guidelines for the management of anaphylaxis in the emergency department. J Accid Emerg Med. Anaphylaxis in schools and other child care settings. Hazinski MR. Baskett PJF. Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care: an international consensus on science. Part 8: Advanced Challenges in Resuscitation. Kemp SF. Oppenheimer J.

Lang DM. Bernstein IL. Nicklas RA. Joint Task Force on Practice Parameters. The diagnosis and management of anaphylaxis: an updated practice parameter. Deakin CD. Nolan JP. European Resuscitation Council guidelines for resuscitation Section 7.

Cardiac arrest in special circumstances. Bock SA. Symposium on the definition and management of anaphylaxis: summary report. The early symptoms may be mild, including itchy eye, runny nose or rash; but these symptoms can quickly lead to more serious problems like: Facial swelling Trouble breathing Tightness of the throat Nausea Abdominal pain Vomiting Diarrhea Fainting Cardiac arrest The first line of defense in combating severe allergic reaction is epinephrine.

What Is Epinephrine? How Epinephrine Stops Allergic Reactions Epinephrine produces multiple functions by binding to different receptors of cells in the body.

Administering Epinephrine Epinephrine should be injected into the middle of the outer side of the thigh. Do not administer epinephrine to any other part of the body, including the: Buttocks Fingers Hands Feet Arm A second dose of epinephrine should be injected if the initial anaphylaxis symptoms do not improve after 10 minutes of the first treatment. Request An Appointment. Allergist ENT. Year This field is for validation purposes and should be left unchanged.

Book Online Book Now. Request Appointment Our Office. Stay in Touch. All Rights Reserved. Sign In or Create an Account. Search Close. Create Account. Advanced Search. Skip Nav Destination Article Navigation. Close mobile search navigation Article navigation. Volume , Issue 3. Previous Article Next Article. Clinical Features of Anaphylaxis.

Primary Role of Epinephrine. Epinephrine Administration and Dosing. Safety of Epinephrine. Dilemmas in Epinephrine Dosing. Prescribing EAs. Using EAs. Lead Authors.

Section on Allergy and Immunology Executive Committee, — Liaison to the Section on Allergy and Immunology. Article Navigation. Sicherer, MD ; Scott H. Sicherer, MD. This Site. Google Scholar. Simons, MD ; F. Simons, MD. Todd A. Mahr, MD ; Todd A. Mahr, MD. Stuart L. Abramson, MD ; Stuart L. Abramson, MD. Thomas A. Fleisher, MD ; Thomas A. Fleisher, MD. Jennifer S. Kim, MD ; Jennifer S. Kim, MD. Elizabeth C. Matsui, MD Elizabeth C.

Matsui, MD. Address correspondence to Scott H. E-mail: scott. Pediatrics 3 : e Cite Icon Cite. Have a written anaphylaxis emergency action plan. Inject epinephrine adrenaline IM in the mid-outer aspect of the thigh by using an EA.

If needed, give a second injection 5 to 15 minutes after the first. Elevate the lower extremities. Do not allow standing, walking, or running. Transport the patient to an emergency department, preferably by an EMS vehicle, for further assessment and monitoring. Additional treatment, including supplemental oxygen, intravenous fluids, and other interventions may be needed. View Large. World Allergy Organization guidelines for the assessment and management of anaphylaxis.

Search ADS. Anaphylaxis: unique aspects of clinical diagnosis and management in infants birth to age 2 years. Age-related differences in the clinical presentation of food-induced anaphylaxis. Antibiotic allergies in children and adults: from clinical symptoms to skin testing diagnosis. Fatal and near-fatal anaphylactic reactions to food in children and adolescents.

Adrenaline auto-injectors for the treatment of anaphylaxis with and without cardiovascular collapse in the community. Early treatment of food-induced anaphylaxis with epinephrine is associated with a lower risk of hospitalization. H 1 -antihistamines for the treatment of anaphylaxis: Cochrane systematic review. Comparison of cetirizine and diphenhydramine in the treatment of acute food-induced allergic reactions. H 2 -antihistamines for the treatment of anaphylaxis with and without shock: a systematic review.

Anaphylaxis in a New York City pediatric emergency department: triggers, treatments, and outcomes. Use of multiple doses of epinephrine in food-induced anaphylaxis in children.