Anaphylaxis in the Emergency Department. Dr. Nelly Gang Emergency department Sheba Medical Center

Transcription

1 Anaphylaxis in the Emergency Department Dr. Nelly Gang Emergency department Sheba Medical Center

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3 הצג ת מק ר ה מגיעה לר ופא לזריקה שגרתית עם נזלת אלרגית ברקע,,19 בתת וזה אחרי מס' אימונותרפיה של אלרגן במסגרת של בעברה שעברו ללא בעיה מיוח דת. זריקות דומות בהמשך ד קות אחרי קבלת הזריקה הופיע גר ד בכפות ידיים, כ- 20 אודם מפושט תחושת נפיחות בגרון, תחושה של קוצר נשימה, סטורציה 50\110,, 110 ל.דד: דופק בבדיקה - והזעה מוגברת. בהאזנה מעל רא ות תקינה, מפושטים. -צפצופים

4 אנפילקסיס? מה מכוון אותנו לאבחנה של מה הטיפול המתאים במקרה זה? מה סוג המעקב וההמ לצות אחרי נסיגת התסמינים?

5 Epidemiology The true incidence is unknown 1 in 1,100 (USA) 1 in 2,300 and 1 in 1,500 (UK) Lifetime risk of anaphylaxis: 1-3% 1 Mortality 4%

6 Increased risk for death Risk factors: β-blockade Adrenal insufficiency Asthma IHD During the acute event: Severe hypotension, bradycardia,, sustained bronchospasm,, poor response to epinephrine

7 Definition A A severe allergic reaction to any stimulus, having sudden onset and generally lasting less than 24 hours, involving one or more body systems and producing one or more symptoms such as hives, flushing, itching, angioedema, stridor,, wheezing, shortness of breath, vomiting, diarrhea, or shock Canadian Pediatric Surveillance Program

8 The most severe systemic allergic reaction that is potentially fatal The severity of previous reactions does not predict the severity of subsequent reactions Results from the immunologically induced release of mast cell and/or basophil mediators after exposure to a specific antigen in previously sensitized individuals Death may occur most commonly from cardiovascular collapse or airway obstruction, or both

9 Pathophysiology The mediators: histamine (H1+H2), leukotriens,, Nitric Oxide Smooth muscle contraction Vasodilatation Increased vascular permeability- transfer of as much as 50% of the intravascular fluid into the extravascular space within 10 min. Reduced venous return Activation of vagal pathways Urticaria, angioedema, bronchonstriction and hypotension

10 Anaphylactic shock Hypovolemic capillary fluid leak Distributive - vasodilatation Cardiogenic reduced contractility, inappropriate bradycardia Obstructive? - pulmonary arteries vasospasm Reduced ability to compensate

11 Causes of anaphylaxis IgE-mediated mediated: insect stings, medications, latex, peanuts and tree nuts, shellfish and fish, milk, eggs and wheat Anaphylactoid: (non IgE- mediated): opiates, NSAIDs, Radiocontrast agents Exercise-induced induced Idiopatic The leading known cause food anaphylaxis

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13 Clinical manifestations The more rapid the onset, the more severe the event The onset within minutes, but occasionally occur as late as 1 hour after the exposure About 20% will follow a biphasic course: the mean time to onset 10 hours (up to hours). Protracted anaphylaxis: lasts longer than 24 hours, has a poor prognosis

14 Clinical manifestations (cont ) Mild (skin and subcutaneous tissues only 90%): Generalized erythema, urticaria, periorbital edema or angioedema Moderate (features suggesting respiratory, cardiovascular or gastrointestinal involvement %): Dyspnea, stridor, wheeze, dizziness (presyncope), diaphoresis, chest or throat tightness, tachycardia or abdominal pain nausea, vomiting Severe (hypoxia, hypotension or neurological compromise): Cyanosis or SpO2 92%, hypotension (SBP <90 mmhg in adults), relative bradycardia, confusion, collapse, LOC or incontinence

15 Clinical manifestations Diagnosis Laboratory studies: Histamine: : begin to increase within min. Remain increased for 30 to 60 min. Tryptase: : peak hours after the onset. Can persist for as long as 5 hours There can be a dissociation between histamine and tryptase

16 Differential diagnosis Vasovagal reaction the most common Severe asthma Panic attack Foreign body aspiration Pulmonary embolism Systemic mast cell disorders Hereditary angioedema Scombroid poisoning

17 Management

18 Adrenalin Stimulation of ά adrenoceptors: : PVR,, BP, improving coronary perfusion, reversing peripheral vasodilatation, angioedema Stimulation of β1 adrenoceptors: : positive inotropic and chronotropic cardiac effects Stimulation of β2 2 receptors: bronchodilatation, camp in mast cells and basophils,, reducing release of inflammatory mediators No contraindications!

19 Drug interactions β blockers: more severe anaphylaxis, decrease the effectiveness of adrenalin The dose of adrenalin should be halved d\t unopposed α stimulation and reflex vagotonic effect (bradicardia,, hypertension, coronary constriction, bronchoconstriction) Glucagon and isotonic volume expansion (up to 7 L) might be necessary Glucagon activate adenyl cyclase directly and bypassing the β-adrenergic receptor

20 Evaluation History : onset and location The potential cause (food, medication, insect bite, contrast media, exercise.) Past medical history and reactions

21 Physical examination Level of consciousness (hypoxia?) Upper and lower airways (dysphonia( dysphonia, stridor, cough, wheezing, dyspnea) CV system (BP, HR, arrhythmias) Skin (diffuse or localized erythema, pruritus, urticaria,, and/or angioedema) GI system (nausea, vomiting, diarrhea)

22 Management Place patient in recumbent position and elevate the lower extremities Establish and maintain airway. Early intubation! Oxygen, inhaled β2 agonist (ventolin) Fluids: NS (not Ringer Lactate): rapid infusion of 1-2L at rate of 5-10 ml/kg in the first 5 min. children- up to 30 ml/kg in the first hour.

23 Management (cont ) Epinephrine 1:1,000 (1mg/ml) 0.3 to 0.5 ml (0.01 mg/kg in children, max. 0.3 mg) IM every 5 min. If no response: 1:10, to 0.3 ml IV over several min. Monitor! Glucagon (β blocker therapy) 1-55 mg IV over 5 min. Inf.: µg/min If cardiopulmonary arrest ACLS. Prolonged resuscitation is encouraged.

24 Management (cont ) Promethazine (Phenergan)) (H1) 25-50mg 50mg IV\IM IM (urticaria, angioedema) Ranitidine (H2) 50mg IV. Synergistic effect. Inhaled β agonist (bronchospasm) Vasopressors: : dopamine µg\kg (relative bradycardia), norepineprine 2-12µg/min (tachycardia) Glucocorticoids no effect for 4-6h. 4 Potentially prevent protracted or biphasic anaphylaxis. Every 6h, 1-22 mg/kg/d.

25 Management (cont ) Observation for 6 hours In more severe cases (use of adrenalin) for 24 hours Discharge with antihistamine and steroid treatment for 3 days Prescribe Epi-Pen! Referral to allergy specialist

26 Back to the case.. IV access and rapid fluid bolus infusion Ventolin via nebulizer Adrenalin 0.3cc IM Phenergane 50 mg IV Ranitidine 50 mg IV Methylprednisolone 125 mg IV

27 Take home message: Prompt recognition of the signs and symptoms of anaphylaxis Early administration of adrenalin Early and rapid volume resuscitation Familiarity with second line therapies Prompt observation Education of the patient Prescription of EpiPen Referral to an allergy specialist