1. Anaphylaxis Michael Kenney CCFP(EM)

2. Outline 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

3. Significance 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

4. Case 36f generalized urticarial rash 2h ago

5. Definition 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

6. Pathophys 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

7. Clinical Manifestations?

8. Clinical Manifestations Cutaneous 90% Urticaria, angioedema, flushing pruritis alone Respiratory 55% Wheeze UA angioedema Near syncope, hypotension35% GI 30% Nausea, vomiting, diarrhea Cramping common Cutaneous 90% Urticaria, angioedema, flushing pruritis alone Respiratory 55% Wheeze UA angioedema Near syncope, hypotension35% GI 30% Nausea, vomiting, diarrhea Cramping common

9. Clinical 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

10. Why do patients die?

11. Critical 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

12. Causes? @ 35% remain unidentified

13. Causes Foods Peanuts Crustaceans Drugs Penicillin, ASA Stings Hymenoptera Exercise Latex Foods Peanuts Crustaceans Drugs Penicillin, ASA Stings Hymenoptera Exercise Latex

14. Case 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

15. 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

16. Case 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

17. DDx 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

18. Case 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

19. High Risk Groups Asthmatics Beta blocked CAD Asthmatics Beta blocked CAD

20. Biphasic 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

21. Clinical 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

22. Management 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

23. Epinephrine 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

24. Epinephrine 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

25. IV 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

26. Nebulized 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

27. Management 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

28. Case 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

29. Airway 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

30. Case 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

31. Anaphylactic 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

32. Disposition 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

33. Instructions 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

34. Summary 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