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