AnaphylaxisAnaphylaxis

Michael Kenney CCFP(EM)Michael Kenney CCFP(EM)

OutlineOutline

Case-based Clinical features

DDx High risk patients Biphasic reaction

Focus on management Highlight specific aspects

Airway Shock

Disposition

Case-based Clinical features

DDx High risk patients Biphasic reaction

Focus on management Highlight specific aspects

Airway Shock

Disposition

SignificanceSignificance

Common 1% fatal

Wide spectrum of presentation Mild - life-threatening Identify the impending disaster

Affects young people Good outcomes expected

Deterioration can be sudden Must have management strategies firmly embedded

Common 1% fatal

Wide spectrum of presentation Mild - life-threatening Identify the impending disaster

Affects young people Good outcomes expected

Deterioration can be sudden Must have management strategies firmly embedded

CaseCase

36f generalized urticarial rash 2h ago 36f generalized urticarial rash 2h ago

DefinitionDefinition

Poorly defined Clinical definition

Severe, potentially life-threatening, multisystem allergic response

more than one system Cutaneous Respiratory Cardiovascular GI manifestations

Poorly defined Clinical definition

Severe, potentially life-threatening, multisystem allergic response

more than one system Cutaneous Respiratory Cardiovascular GI manifestations

Pathophys BasicsPathophys Basics IgE mediated Mast cell/basophil degranulation Sensitization required

H1 and H2 receptors (…H7)

Smooth muscle contraction Capillary leakage Mucosal edema/mucus production Vasodilation

IgE mediated Mast cell/basophil degranulation Sensitization required

H1 and H2 receptors (…H7)

Smooth muscle contraction Capillary leakage Mucosal edema/mucus production Vasodilation

Clinical Manifestations?Clinical Manifestations?

Clinical ManifestationsClinical Manifestations Cutaneous 90%

Urticaria, angioedema, flushing pruritis alone

Respiratory 55% Wheeze UA angioedema

Near syncope, hypotension 35% GI 30%

Nausea, vomiting, diarrhea Cramping common

Cutaneous 90% Urticaria, angioedema, flushing pruritis alone

Respiratory 55% Wheeze UA angioedema

Near syncope, hypotension 35% GI 30%

Nausea, vomiting, diarrhea Cramping common

Clinical ManifestationsClinical Manifestations

5-60 minutes Most fatalities within 30min Parenteral 5-30min Oral route up to 2 hours

Mild Sx to impending catastrophe within minutes

5-60 minutes Most fatalities within 30min Parenteral 5-30min Oral route up to 2 hours

Mild Sx to impending catastrophe within minutes

Why do patients die?Why do patients die?

Critical CareCritical Care

Airway Significant angioedema Hoarse voice Stridor

Breathing Aggressive management of bronchospasm

Circulation Shock

Airway Significant angioedema Hoarse voice Stridor

Breathing Aggressive management of bronchospasm

Circulation Shock

Causes?Causes?

@ 35% remain unidentified @ 35% remain unidentified

CausesCauses Foods

Peanuts Crustaceans

Drugs Penicillin, ASA

Stings Hymenoptera

Exercise Latex

Foods Peanuts Crustaceans

Drugs Penicillin, ASA

Stings Hymenoptera

Exercise Latex

CaseCase

25m, healthy, comes from the gym flushing, pruritis, SOB, lightheadedness Pad Thai 4 hours prior

25m, healthy, comes from the gym flushing, pruritis, SOB, lightheadedness Pad Thai 4 hours prior

Food Dependent Exercise Induced Anaphylaxis

Food Dependent Exercise Induced Anaphylaxis

More prevalent that one would think 2-4 hours post ingestion Allergy testing helpful in avoidance

More prevalent that one would think 2-4 hours post ingestion Allergy testing helpful in avoidance

CaseCase

48m, healthy, severe flushing, pruritis, throbbing HA, diarrhea

15min post ahi tuna ingestion Vitals stable

48m, healthy, severe flushing, pruritis, throbbing HA, diarrhea

15min post ahi tuna ingestion Vitals stable

DDxDDx

Flushing syndromes Carcinoid VIP secreting tumours

“Restaurant” syndromes MSG, sulfites Scombroidosis

Endogenous Histamine syndromes Mastocytosis Leukemias

Sepsis

Flushing syndromes Carcinoid VIP secreting tumours

“Restaurant” syndromes MSG, sulfites Scombroidosis

Endogenous Histamine syndromes Mastocytosis Leukemias

Sepsis

CaseCase

62m, 30min post dinner Generalized flushing Vomited once, abdo cramping SOB/chest tightness

HR 62 RR 28 BP 159/96 94% RA

62m, 30min post dinner Generalized flushing Vomited once, abdo cramping SOB/chest tightness

HR 62 RR 28 BP 159/96 94% RA

High Risk GroupsHigh Risk Groups

Asthmatics Beta blocked CAD

Asthmatics Beta blocked CAD

Biphasic ReactionBiphasic Reaction < 8 hours typical Can occur up to 72 hours 0.5 - 20% patients Less, equal or greater than initial

reaction No clinical predictors

Ingested allergen more often associated Corticosteroids do not clearly reduce

incidence or severity

< 8 hours typical Can occur up to 72 hours 0.5 - 20% patients Less, equal or greater than initial

reaction No clinical predictors

Ingested allergen more often associated Corticosteroids do not clearly reduce

incidence or severity

Clinical SummaryClinical Summary More than urticaria Fatal ABC’s Timing of exposure Systems involved High risk PMHx Etiology Biphasic Hx

More than urticaria Fatal ABC’s Timing of exposure Systems involved High risk PMHx Etiology Biphasic Hx

ManagementManagement

ABC’s Drugs

Epinephrine SC/IM/IV nebulized

Antihistamines Anti-H1 and H2

Corticosteroids Bronchodilators Glucagon

ABC’s Drugs

Epinephrine SC/IM/IV nebulized

Antihistamines Anti-H1 and H2

Corticosteroids Bronchodilators Glucagon

EpinephrineEpinephrine

Alpha increases PVR decreases vascular permeability

Beta bronchodilation stimulates increased cardiac output prevents further mediator release (cAMP)

Side effects

Alpha increases PVR decreases vascular permeability

Beta bronchodilation stimulates increased cardiac output prevents further mediator release (cAMP)

Side effects

EpinephrineEpinephrine Drug of choice

Mild-moderate systemic manifestations Epinephrine 1:1000

Usual dose 0.3 mg = 0.3mL Think epi-pen (small volume) IM dosing in thigh preferred (multiple studies

demonstrating benefit over SC dosing in deltoid) Repeat every 5-10 minutes prn

Severe life-threatening manifestations Epinephrine 1:10,000 (crash cart epi)

Max single dose 0.1mg = 1mL IV

Drug of choice

Mild-moderate systemic manifestations Epinephrine 1:1000

Usual dose 0.3 mg = 0.3mL Think epi-pen (small volume) IM dosing in thigh preferred (multiple studies

demonstrating benefit over SC dosing in deltoid) Repeat every 5-10 minutes prn

Severe life-threatening manifestations Epinephrine 1:10,000 (crash cart epi)

Max single dose 0.1mg = 1mL IV

IV EpiIV Epi

Crash car epi Draw 1 mL into 10 mL syringe Fill up syring with NS 0.1mg total (10ug/mL) Give 1mL every 30-60 seconds Repeat

Crash car epi Draw 1 mL into 10 mL syringe Fill up syring with NS 0.1mg total (10ug/mL) Give 1mL every 30-60 seconds Repeat

Nebulized EpiNebulized Epi

1:1000 <20kg, 2.5mL >20kg, 5mL Can run continuous x 3

Laryngeal edema Bronchoconstriction

In some cases does actually reach therapeutic blood levels

1:1000 <20kg, 2.5mL >20kg, 5mL Can run continuous x 3

Laryngeal edema Bronchoconstriction

In some cases does actually reach therapeutic blood levels

ManagementManagement Diphenhydramine (anti H1)

50mg IV Ranitidine (anti H2)

50mg IV Methylprednisolone

125mg IV Glucagon

1-5mg IV q5min to effect Bronchodilators

Continuous sabutamol/ipratropium nebs

Diphenhydramine (anti H1) 50mg IV

Ranitidine (anti H2) 50mg IV

Methylprednisolone 125mg IV

Glucagon 1-5mg IV q5min to effect

Bronchodilators Continuous sabutamol/ipratropium nebs

CaseCase

20m asthmatic, wasp sting, generalized urticaria, hoarse voice, wheezing

HR 130 RR 36 BP 110/70 sat 93% RA

20m asthmatic, wasp sting, generalized urticaria, hoarse voice, wheezing

HR 130 RR 36 BP 110/70 sat 93% RA

Airway in AnaphylaxisAirway in Anaphylaxis

Early clues Nebulized epi Aggressive medical therapy Be humble/be prepared

Backup help and DAC Don’t paralyze

Ketamine ideal Take a look

Early clues Nebulized epi Aggressive medical therapy Be humble/be prepared

Backup help and DAC Don’t paralyze

Ketamine ideal Take a look

CaseCase

42f, flushed, pre-syncopal, N/V, SOB post cookie ingestion

Looks unwell EMS have treated as per protocol HR 140 BP 88/56 RR 36 sats 95% RA

42f, flushed, pre-syncopal, N/V, SOB post cookie ingestion

Looks unwell EMS have treated as per protocol HR 140 BP 88/56 RR 36 sats 95% RA

Anaphylactic ShockAnaphylactic Shock

Complex Vasodilation, leakage, intravascular depletion

Fluids and Epi are key to Tx Bolus 2L immediately Can give epi peripherally

You give the epi and run the scene Have someone else start CVC

Complex Vasodilation, leakage, intravascular depletion

Fluids and Epi are key to Tx Bolus 2L immediately Can give epi peripherally

You give the epi and run the scene Have someone else start CVC

DispositionDisposition

Controversial Nothing in literature to support set time Biphasic reaction usually < 8 hours Severe reactions

Admit for 24h if airway or BP was signficant concern

Controversial Nothing in literature to support set time Biphasic reaction usually < 8 hours Severe reactions

Admit for 24h if airway or BP was signficant concern

InstructionsInstructions

Spend the time Allergen avoidance, symptom recognition, meds

Script for Epi pen Need more than 1

Steroids to go Benadryl to go Referral to allergist

Via GP or directly

Spend the time Allergen avoidance, symptom recognition, meds

Script for Epi pen Need more than 1

Steroids to go Benadryl to go Referral to allergist

Via GP or directly

SummarySummary

Multi-system High risk patients Biphasic reactions General management

Focus on Epinephrine Airway management Shock management Disposition and instructions

Multi-system High risk patients Biphasic reactions General management

Focus on Epinephrine Airway management Shock management Disposition and instructions