Anaphylaxis & Acute Allergic Reactions in the Emergency Department Theodore J. Gaeta, DO, MPH Sunday Clark, MPH Carlos A.

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Transcript Anaphylaxis & Acute Allergic Reactions in the Emergency Department Theodore J. Gaeta, DO, MPH Sunday Clark, MPH Carlos A.

Anaphylaxis & Acute Allergic Reactions in the Emergency Department

Theodore J. Gaeta, DO, MPH Sunday Clark, MPH Carlos A. Camargo, Jr., MD, DrPH On behalf of the MARC Investigators www.emnet-usa.org

Outline

Case Presentation

Prevalence and Natural History

Pathophysiology

ED Diagnosis and Management

Food-related Allergic Reactions

Post-care Plans

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Case Presentation

19 year old female with acute onset dyspnea

Dyspnea, wheezing, vomiting and generalized flushing

“minutes after eating a chocolate chip cookie”

Past medical history: eczema

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Case Presentation

(continued) Vital signs

SBP 80/p, P 124, R 40, T 98.8

o F (37.1

o C)

Airway patent, diminished breath sound at the bases with wheezing in the upper fields

Weak pulses with delayed capillary refill

Diffuse erythematous rash observed and Medic Alert tag indicates peanut allergy

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Anaphylaxis

Multi-system syndrome resulting from mediator release

Acute onset

Varies from mild and self-limited to fatal

IgE and non-IgE mediated

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Anaphylaxis

Incidence

21 per 100,000 person-years (95% confidence interval [CI]: 17 - 25 per 100,000 person-years) 1

10.5 per 100,000 person-years among children (95% CI: 8.1 – 13.3 per 100,000 person-years) 2 1

Yocum et al. J Allergy Clin Immunol 1999

2

Bohlke et al. J Allergy Clin Immunol 2004

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Estimated prevalence of Generalized Allergic Reaction*

Insect sting Food Drug RCM Allergen immuno Tx Latex All causes 3% of adults 1-3% of children 1% of adults 0.1% of cases 3% of patients 1% of adults 5% of adults

*urticaria / angioedema or dyspnea or hypotension

Anaphylaxis - Clinical Manifestations

Cardiovascular:

Tachycardia then hypotension

– –

Shock:

50% intravascular volume loss Bradycardia (4%) (transient or persistent)*

Myocardial ischemia

Lower respiratory: bronchoconstriction wheeze, cough, shortness of breath

Upper respiratory:

Laryngeal/pharyngeal edema

Rhinitis symptoms

Fisher. Anesth Intens Care 1986

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Anaphylaxis - Clinical Manifestations

Cutaneous: Pruritus, urticaria, angioedema, flushing

Gastrointestinal: Nausea, emesis, cramps, diarrhea

Ocular: Pruritus, tearing, redness

Genitourinary: Urinary urgency, uterine cramps

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Anaphylaxis -Temporal Pattern

Uniphasic

Biphasic

Initial allergic reaction

Recurrence of same manifestations up to 8 hours later

Protracted

Up to 32 hours

May not be prevented by glucocorticoids

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Anaphylaxis Mediators

Histamine

H1: smooth muscle contraction vasc permeability

H2: vascular permeability

H1+H2: vasodilatation, pruritus

 

Leukotrienes

Smooth muscle contraction

vascular permeability and dilatation Nitric Oxide

– –

Smooth muscle relaxation vascular permeability and dilatation

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Causes of Anaphylaxis

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Causes of IgE-Mediated Anaphylaxis

Antibiotics and other medications

-lactams, tetracyclines, sulfas

Foreign proteins Latex, hymenoptera venoms, heterologous sera, protamine, seminal plasma, chymopapain

Foods Shellfish, peanuts, and tree nuts

Exercise induced

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Causes of Anaphylactoid Mediator Release

Complement activation

– – –

Iodinated dye Aggregated IgG IgA deficiency

Unknown mechanisms

– – –

Aspirin Opiates Local anesthetics

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Severity of Anaphylaxis Risk Factors

Male

Consistent antigen administration

Shorter time elapsed since last reaction

Asthma

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Anaphylaxis Fatalities Post Mortem Findings

Airway (laryngeal) and tissue (visceral) edema

Pulmonary hyperinflation

Tissue eosinophilia

Elevated serum tryptase

Myocardial injury

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Anaphylaxis Fatalities

Fatalities

@

4%

Increased risk

– 

blockade, severe hypotension, bradycardia, sustained bronchospasm, poor response to epinephrine

Adrenal insufficiency

Asthma

Coronary artery disease

Van der Klauw et al. Clin Exp Allergy 1996

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Anaphylaxis Fatalities

60 50 40 30 20 10 0 0-9 10-19 Age 20-29

Bock SA et al. J Allergy Clin Immunol 2001

30+

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Anaphylaxis Differential Diagnosis

Vasovagal syncope

Systemic mastocytosis

Scombroid (fish) poisoning

Other causes of shock

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Anaphylaxis Diagnosis

Clinical features

Serum tryptase (measurable up to 6 hours)

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Anaphylaxis Treatment

O 2 , airway maintenance & IV fluids

Loose tourniquet? (to extremity for bee sting)

Epinephrine

0.01 ml/kg (1:1000) IM q 10-20 min (max 0.3-0.5 ml)

In shock, 0.5- 5 mcg/min (1:10,000) IV to maintain SBP

H1 + H2 histamine receptor antagonists

Diphenhydramine, 1 mg/kg PO/ IM/ IV (max 75 mg)

Ranitidine

Adult, 4 mg/kg PO (max 300 mg), 50 mg IM/IV q 6 h

Child, 1.5 mg/kg IM/IV (max 50 mg)

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Treatment

(continued)

Corticosteroids

1-2 mg/kg prednisone PO (max 75 mg)

2 mg/kg methylpredisolone IV (max 250 mg)

Not effective in protracted anaphylaxis

Effective in iodinated dye prophylaxis

Inhaled beta-agonists Albuterol 2.5 mg q 15-20 min

Glucagon (consider if patient is on

-blocker)

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Return to case

Placed on supplemental O 2 monitor and cardiac

IV access and fluid bolus

Albuterol via nebulizer

Epinephrine: 0.3 ml IM

Diphenhydramine: 50 mg IV

Ranitidine: 50 mg IV

Methylpredisolone: 125 mg IV

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Response

Despite multiple doses of epinephrine and albuterol the patient remained in respiratory distress

Impending respiratory failure: Rapid sequence intubation

Transferred to ICU

Further history: The patient’s roommate presents a Medic Alert tag indicating peanut allergy

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Food-Related Allergic Reaction

Epidemiology

Fatal

Peanut

Schools

Exercise

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Fatal Food Anaphylaxis

     

Frequency (USA): ~ 150 deaths / year Risk:

– – – –

Underlying asthma Delayed epinephrine Symptom denial Previous severe reaction History: known allergic food Key foods: peanut / tree nuts / shellfish Biphasic reaction Lack of cutaneous symptoms

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Prevalence of Food Allergy

Perception by public: 20-25%

Confirmed allergy (oral challenge)

– –

Adults: 1-2% Infants/Children: 6-8%

Dye / preservative allergy (rare)

Specific Allergens

– – –

Dependent upon societal eating pattern Milk (infants): 2.5% Peanut / tree nuts in general population: 1.1%

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Diagnosis: History / Physical

History: symptoms, timing, reproducibility

Acute reactions vs. chronic disease

Diet details / symptom diary

Specific causal food(s)

“Hidden” ingredient(s)

Physical examination: evaluate disease severity

Identify general mechanism

– –

Allergy vs. intolerance IgE vs. non-IgE mediated

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Disposition

Most patients with allergic reactions can be discharged

Hospitalize or observe patients with airway angioedema, persistent brochospasm, hypoperfusion, cardiac problems, on

-blockers

Observe 4 to 6 hours

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Risk Management for Anaphylaxis

Education

– – –

Allergen avoidance Written emergency action plan Resources (eg, FAAN website: www.foodallergy.org

)

Prescription for self-injectable epinephrine

Referral to an allergy specialist

Anaphylaxis – Operational Definition

Two or more organ systems

– – –

skin (e.g., hives) respiratory (e.g., swelling of the lips, tongue, or throat; trouble breathing or shortness of breath; stridor, wheezing)

cardiovascular (e.g., hypotension, dizziness or fainting, altered mental status) gastrointestinal (e.g., trouble swallowing, abdominal pain)

Hypotension (SBP <100 mmHg)

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“State of the ED” Objective

To describe ED management of food allergy

Methods

The Multicetner Airway Research Collaboration is a program within the Emergency Medicine Network (www.emnet-usa.org)

Clark et al. J Allergy Clin Immunol 2004

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9/22/04

EMNet Sites

(137 US sites)

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Methods

(continued)

21 North American EDs participated in this study

Chart review of randomly selected patients presenting to the ED over a one year period with physician-diagnosed food allergy

ICD-9 codes

693.1 (dermatitis due to food)

– – –

995.0 (other anaphylactic shock) 995.3 (allergy, unspecified) 995.60 (allergy due to unspecified food)

995.61-995.69 (allergy due to specified foods)

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Results

678 patients with physician-identified food allergy were randomly selected for chart review

57% female, 43% white

Mean age, 29 ± 18 years

92% had documentation of a specific food item as the cause of the current reaction

Only 41% of patients had documentation of a history of allergic reaction to the specific food that caused the current reaction

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Specific Foods

*

Crustaceans Peanut Fruits and vegetables Fish Tree nuts Milk Eggs Additives Other foods

Percentage

19 12 12 10 9 6 2 1 36

95% CI

16 – 22 9 – 14 10 – 15 8 – 12 7 – 11 4 – 8 1 – 4 0.5 – 2 33 – 40

* More than one option allowed.

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Presentation and ED Course

Arrived by ambulance (%) Duration of symptoms  1 hour (%) n=678 18 37 Received antihistamines in ED (%) Received systemic steroids in ED (%) Received epinephrine in ED (%) Respiratory treatments in ED* (%) Discharged to home (%) 72 48 16 33 97 95% CI 16 – 22 33 – 41 68 – 75 45 – 52 13 – 19 29 – 37 95 – 98

* Inhaled

-agonists and inhaled anticholinergics

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Outcomes

Given discharge instructions to avoid offending allergen (%) Given prescription for self-injectable epinephrine at ED or hospital discharge (%) Referred to an allergist at ED or hospital discharge (%) n=642 40 16 12 95% CI 36 – 43 14 - 20 9 - 15 www.emnet-usa.org

Instructions to Avoid Offending Allergen

100 90 30 20 10 0 80 70 60 50 40 Goal = 100% M O R Q I Overall: 40% (95% CI, 36-43%) S J L P H Site C E A N B K F T G D www.emnet-usa.org

Self-injectable Epinephrine at Discharge

100 90 80 70 60 50 40 30 20 10 0 B Goal = 100% F N Q D I E K Overall: 16% (95% CI, 14-20%) P G Site L R C T S H U J M O www.emnet-usa.org

100

Referred to Allergist at Discharge

90 80 30 20 10 0 70 60 50 40 Goal = 100% Overall: 12% (95% CI, 9-15%) H K Q R E P B D I L Site S C G M N J A T F O www.emnet-usa.org

Summary

Although allergic reactions to food can be life threatening, 18% of patients came to the ED by ambulance and only 3% were admitted

A variety of foods provoked the allergic reaction, with crustaceans and peanuts being the most common triggers

Only 16% of patients received a prescription for self-injectable epinephrine when leaving the ED

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Summary

(continued)

Similarly, only 12% were referred to an allergist as part of discharge instructions

At a minimum, there is poor documentation of medications prescribed at ED discharge

Although guidelines suggest specific approaches for the emergency management of food allergy, concordance to these guidelines appears low

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Take Home

Keys to successful management

Prompt recognition of the signs and symptoms of anaphylaxis

Early administration of IM epinephrine

Volume resuscitation

Comfort and familiarity with 2 nd therapies line

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Take Home

(continued) A successful post-care plan must include

Education

Allergen avoidance

• •

Written emergency action plan Educational resources (eg, www.foodallergy.org)

Prescription for self-injectable epinephrine

Referral to an allergy specialist

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