Allergic Emergencies and Anaphylaxis. George Porfiris MD, CCFP(EM),FCFP TEGH

Transcription

1 Allergic Emergencies and Anaphylaxis George Porfiris MD, CCFP(EM),FCFP TEGH

2 Copyright 2017 by Sea Courses Inc. All rights reserved. No part of this document may be reproduced, copied, stored, or transmitted in any form or by any means graphic, electronic, or mechanical, including photocopying, recording, or information storage and retrieval systems without prior written permission of Sea Courses Inc. except where permitted by law. Sea Courses is not responsible for any speaker or participant s

3 Pre-test The most common cause of death in patients with anaphylaxis is: a) iatrogenic (medical therapy) b) stroke c) circulatory collapse d) DIC e) airway obstruction

4 Pre-test Epinephrine can be given: a) IV b) IM/SC c) aerosolized d) IT e) all of the above

5 Pre-test The most common cause of anaphylaxis in children is: a) food b) medication c) insect sting d) inhaled allergen e) idiopathic

6 Pre-test A patient on beta blockers presents hypotensive after multiple bee stings. Epinephrine is given but has minimal effect. You should also give: a) insulin b) glucagon c) calcium d) potassium e) uranium

7 Pre-test A patient presents with flushing, urticaria, headache, nausea and vomiting 30 minutes after eating a tuna fish sandwich. The diagnosis is: a) ciguatera poisoning b) scombroid poisoning c) Captain Highliner s reaction d) acute intermittent porphyria e) Salmonella

8 Spectrum of Allergic Reactions Urticaria Angioedema (bradykinin vs histamine mediated) Anaphyalaxis (mild, moderate, severe)

9 Anaphylaxis Classic IgE response, need prior exposure antigen binds to IgE sitting on mast cells releases inflammatory mediators: histamine, leukotrienes, prostoglandins causes enhanced vascular permeability, hypotension,smooth muscle contraction, increased mucous

10 Anaphylactoid Reactions bypass IgE mediated pathways do not need prior exposure so therefore can occur with first exposure to antigen stimulate mast cells directly examples: IV contrast, morphine, NSAIDS

11 Causes Food ( nuts, shellfish, eggs) Drugs ( antibiotics, NSAIDS, IV contrast) Insect stings (wasps, bees, fire ants) latex exercise hereditary

12 Killer antigens Which allergen causes the most anaphylactic deaths in Canada and the US? A) Bee/wasp stings B) Penicillin C) Sulfa D) peanuts

13 Risk Factors Anaphyalaxis on B-blockers history of asthma atopic history of previous reaction on ACE Inhibitor

14 Symptoms and Signs Urticaria only skin involvement classic hives pruritus may have injected eyes and nasal symptoms

15 Anaphylaxis SKIN PLUS ONE: 1) Resp 2) Cardiovascular 3) GI 15

16 Symptoms and Signs Angioedema involves deeper layers of skin well-demarcated localized edema and redness usually on face: lips, eyelids, tongue

17 Angioedema 1) Bradykinin Mediated A) Hereditary:AD, lack of C1 esterase inhibitor usually involves face,airway,gi symptoms no hypotension unresponsive to normal treatment need to give fresh frozen plasma B) ACE inhibitor induced usually within 1 week but can happen years after starting 2) Histamine Mediated (with urticaria)

18 Case 1 55 year old man is brought to RR by DAS. He was at restaurant and accidentally ate cake that had peanuts in it. He has had previous anaphylactic reaction to peanuts. His epi-pen had expired and he did not have it with him. He is on a b-blocker for hypertension.

19 Case 1 (cont) His vitals are BP 90/58, HR=124, RR=26 He is covered in an urticarial rash He has some audible wheezes and feels a funny sensation in his throat He has nausea but no vomiting or diarrhea

20 Case 1 What is your approach?

21 Case 1 ABCs (Always)

22 Approach ABC s ( always) 100% oxygen IV normal saline 1 L bolus monitor (ECG, O2 sat) determine severity always have airway in mind + have low threshold for intubation Remove allergen ( stinger, charcoal)

23 Anaphylaxis Drugs Most important drug is EPINEPHRINE give it as early as possible IM is best route initially adult dose: mg IM (1/1000) peds dose: 0.01mg/kg IM can repeat it every 5 minutes up to 3-5 times

24 IV Epinephrine if life threatening hypotension or airway obstruction use 1/ mg slow IV push q2-3 minutes must be on cardiac monitor be careful in elderly, heart patients

25 Other routes for Epi aerosolized 5 mg of 1/1000 epinephrine in normal saline inject under tongue in life threatening airway obstruction

26 Case 1 What else do we need to give?

27 Antihistamines IV Benadryl 50mg 1 mg/kg for peds H1 blocker

28 Antihistamines IV Zantac (ranitidine) 50 mg 1 mg/kg for peds H2 blocker

29 Steroids IV Solumedrol (methylprednisolone) 125 mg 2 mg/kg (peds) corticosteroid

30 Case 1 What if patient has wheezing?

31 Beta 2 Agonists Ventolin 5 mg nebulized 31

32 What if patient is on a beta blocker?

33 Glucagon 1-2 mg IV Text 33

34 What if the allergen was an oral allergen ingested within one hour of ER visit?

35 Charcoal 50 grams po 35

36 Anaphylaxis Cocktail IV Benadryl 50 mg ( 1-2 mg/kg) IV Zantac 50 mg ( 1 mg/kg) IV Solumedrol 125 mg ( 2.5mg/kg) Ventolin 5 mg nebulized if wheezing Glucagon 1-2mg IV if on b-blocker Atrovent 0.5 mg nebulized if wheezing and on a b-blocker Charcoal 50g po ( 1 g/kg) if oral allergen

37 Disposition: mild symptoms resolved with 1-2 epi (may still have mild rash) no airway compromise no severe hypotension must observe for 4-6 hours no recurrence of symptoms

38 Disposition: mild can discharge home arrange out patient allergy followup must give prescription for: 1) epi-pen 2) Benadryl 50mg q6 hrs x 5d 3) Prednisone 40 mg OD x 5d 4) medic alert bracelet

39 Disposition: moderate needed more than 2 doses of epinephrine had severe hypotension or stridor recurrence of symptoms during 6-8 hour observation Persistent airway symptoms ADMIT to medicine

40 Case 2 A 37 year old female comes in with an itchy rash x 2 days On exam she has normal vital signs The only finding is an urticarial rash on her trunk, proximal limbs and neck

41 Urticaria very common presenting complaint to ER + family doctor s office only skin (+/- nasal + eye) involvement no hypotension no airway involvement no syncope Treat with Benadryl +/- Zantac

42 Scombroid Poisoning usually 30 minutes after eating spoiled fish tuna, mahi-mahi, sardines, anchovies urticaria, flushing, headache GI symptoms due to release of histamine like toxin Treatment: Benadryl + Zantac

43 Summary ABC always airway control is crucial epinephrine is most important drug admit or proper discharge prescription and follow-up