NAME OF DOCUMENT / Acute Management of Anaphylaxis
TYPE OF DOCUMENT / GUIDELINE
DOCUMENT NUMBER / PD 01
DATE OF PUBLICATION / 3/4/2013
RISK RATING
LEVEL OF EVIDENCE
REVIEW DATE
FORMER REFERENCE(S)
EXECUTIVE SPONSOR or
EXECUTIVE CLINICAL SPONSOR / Director of Emergency Department
AUTHOR / Dr. Andrew Bezzina
Senior Staff Specialist Emergency Medicine
KEY TERMS
SUMMARY

Acute Management of Anaphylaxis

Section 1 - Background

Section 2 - Principles

Section 3 - Definitions...... 4

Section 4 - Responsibilities...... 4

Medical Staff are responsible for:...... 4

Nursing Staff are responsible for:...... 4

Section 5 - Acute Management (Adrenaline)...... 5

Section 6 -Other Drugs...... 7

Section 7 -Discharge Plans

Section 8 -

References

Revision and Approval History

Appendix - ………………………………………………………………………………………13

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Background

Section 1 – Background

Anaphylaxis is the most severe form of allergic or type 1 hypersensitivity reaction and is potentially life threatening.

Anaphylaxis should be treated as a medical emergency, requiring immediate treatment.

Anaphylaxisis a systemic event affecting all organ systems.

The diagnosis should be considered in –

  1. Any acute onset of hypotension orbronchospasm or upper airway obstruction

where anaphylaxis is considered possible,even if typical skin features are not present.

  1. Any acute onset illness withtypical skin features (urticarial rash, flushing/ erythema +/- angioedema

PLUS

Involvement of respiratory and/orcardiovascular and/or persistent severe gastrointestinal symptoms.

In some cases, anaphylaxis is preceded by less dangerous localised allergic symptoms.

Severity can be influenced by multiple factors –

  • exercise
  • heat
  • alcohol
  • where food is the allergen - amount eaten, how it is prepared and consumed.

Careful!-

  • Tachycardia in response to hypotension is characteristic BUT sudden bradycardia with cardiovascular collapse and cardiac arrest may occur before any skin features become apparent.
  • Cause of this phenomenon unclear - important clinical feature to recognise in order to avoid making misdiagnosis of a “panic attack” or “vasovagal reaction”.
  • Incidence of biphasic (recurrent) anaphylaxis varies from less than 1% to a maximum of 23%. Additionally, the reported time of onset of the late phase may vary from 1 to 72 hours (most occur within 8-10 h).

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Section 2 - Principles

Principle Statement

  • Where the clinical picture is diagnosed as anaphylaxis immediate intervention with intramuscular adrenaline is the most important first management step in parallel with standard stabilisation methods
  • Medications such as anti histamines and steroids have no acute role to play.
  • Parenteral promethazine should not be used as it has NO benefit and may cause harm with sedation, hypotension or local abscess.
  • All patients with an episode of anaphylaxis will require a management plan on discharge.

EXCLUSIONS

Section 3 - Definitions

Definition:

  • ED – Emergency Department
  • Anaphylaxis – severe allergic reaction as above

Section 4 - Responsibilities

Medical staff areresponsible for -

  • Delivery of acute treatment
  • Disposition decisions and referral to Intensive Care as necessary.
  • Determining an appropriate period of observation after treatment
  • Preparation of an appropriate discharge plan and communication of that plan to the patient and their GP

Nursing staff are responsible for -

  • Delivery of treatment in partnership with medical staff
  • General care of the patient
  • Reinforcement of education of the patient regarding discharge plans etc.

Section 5 -

Acute Management (Adrenaline/Adrenaline/Adrenaline)

  • Remove any identified allergens where possible (e.g. cease antibiotic infusions, cease contrast injection remove bee sting)
  • Enlist senior medical help – ED Lead Medical Officer/ Emergency Physician.
  • Irrespective of the manifestation, once the diagnosis is made administer Intramuscular Adrenaline 0.5 mg IM (0.5ml of 1:1000) in adults OR 10 microgm/kg for children (0.01ml per kg).
  • Adrenaline is repeatable every 5 minutes as necessary.

For specific manifestations –

•Airway – if stridor/ angioedema

–Simple manoeuvres as appropriate.

–If airway obstruction partial

•Nebulised adrenaline (5mg = 5ml of 1:1000)

•Call for Anaesthetist/ Intensivist/ Emergency Physician as available

–If airway obstructed

•BVM

•Needle cricothyroidotomy

•

•Breathing - Bronchospasm

–Salbutamol – as per the management of asthma.

•Circulation – hypotension.

–At least one (preferably 2) large bore cannulae

–Administer intravenous normal saline 20mls per kg and repeat as necessary to maximum of 50ml/kg in 30 minutes

–IV adrenaline – if poor initial response. 1mg in 1000ml Normal Saline and start at 5ml/kg/hr then adjust rate to response.

In patients unresponsive to fluids and adrenaline then consideration can be given to using IV glucagon or intravenous vasopressin. There is limited evidence base for this. Discuss with intensivist or emergency physician before commencing.

Glucagon –1-2mg stat then 1-2 mg/hr if responsive. (For children 10 – 30

microgm/kg to a maximum of 1mg)

Vasopressin – 10 – 40 units IV. Infusion 20 units in 50mls of 5% Dextrose or N/S

and run at 6ml per hour in adults.

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Section 6 –

Other Drugs –

The evidence

Anti Histamines

H1 Blockers - There is NO evidence from randomised controlled trials to support the use of H1

Antihistamines in the acute management of anaphylaxis. There may be a role for

them in control of itch in urticaria but this usually resolves with the administration

of adrenaline. If decision is to use one then a non sedating agent is preferred.

H2 Blockers - significant benefit in the patients with urticaria and in those with urticaria or

angioedema in the H2 antagonist group. The patients however were on the less

severe end of the spectrum of allergic reactions with only a small proportion

having hypotension or airway compromise.

Steroids - there is no evidence from high quality studies for the use of steroids in the

emergency management of anaphylaxis.We can neither support nor refute the

use of these drugs for this purpose. It is however reasonable to administer steroids for 2 to 3 days from the point of onset.

Unless the patient is too sick to swallow there is no benefit of IV versus oral as in other settings.

Doses – Hydrocortisone 2 - 5mg/kg IV then 1mg/kg q6h.

Dexamethasone – 0.1 to 0.4mg/kg oral or IV stat.

Prednisone 1mg/kg daily orally

Section 7

Disposition Decision

  • Any patient who suffers an attack of anaphylaxis must be monitored for a minimum of 4 hours post adrenaline. The aim here is to diagnose rebound or biphasic anaphylaxis.
  • Potential risk factors for biphasic anaphylaxis include

•severity of the initial phase,

•delayed or suboptimal doses of epinephrine during initial treatment

•laryngeal oedema or hypotension during the initial phase,

•delayed onset of symptoms after exposure to the culprit antigen

•prior history of biphasic anaphylaxis.

  • Patients within this group or who have significant associated comorbidities e.g. asthma or who have limited access to return to care should be considered for short stay admission overnight.
  • All patients discharged after an anaphylactic episode will need to have a discharge plan and a script for an epipen/anapen arranged. The discharge plan format can be as per the appendix to this guideline.

NB: Epipens, Anapens are Authority only scripts. Administration of adrenaline in ED for anaphylaxis is enough to justify the script.

There are some authority scripts available in ED that are actually specific to some of the doctors working here. Call the number for authority (1800 888333) and document the appropriate authority number and patient details on one of these scripts. Cross out the name etc of the doctor printed on the script and replace it with your own.

NB: The hospital pharmacy does not routinely stock Epipens. Before discharging the patient ring one of the following pharmacies to ensure availability. If out of hours then give the patient a list of these numbers to call the next available day the pharmacies are open.

Advise the patient to return to their GP or to ED in business hours if they are unable to source a pharmacy with Epipens.

Good Price Warehouse South Nowra 44216333

Terry White Stocklands Nowra 44213166

Priceline Ulladulla 44551150 only adult

Blooms Nowra Mall 44213946

Blooms Kiama 42321046 (use to be Priceline)

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Appendixes

Section 7 –

References

•Anaphylaxis Emergency Management for Health Professionals

Australian Prescriber August 2011 Volume 34 No. 4

•Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock

Sheikh A, Shehata YA, Brown SGA, Simons FER, Cochrane 2008.

•H1-antihistamines for the treatment of anaphylaxis with and without shock

Sheikh A, ten Broek VM, Brown SGA, Simons FER. Cochrane – November 2010 update.

•Glucocorticoids for the treatment of anaphylaxis

Choo KJL, Simons FER, Sheikh A. Cochrane March 2010

Revision and Approval History

Date / Revision no: / Author and approval
27/3/2013 / Dr. Andrew Bezzina. FACEM.

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