Anaphylaxis
Signs
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Rash/hives
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Angioedema
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Hypotension
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Tachycardia
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Hypoxemia
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Bronchospasm/wheezing
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↑ peak inspiratory pressure
Management
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Stop offending agent
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Inform surgeon, call for help
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Discontinue or ↓ all anesthetic agents
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Airway:
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100% O2
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Secure airway
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Administer epinephrine IV in escalating doses:
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Start at 10-100 mcg & ↑ as necessary until clinical improvement
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Consider early epinephrine infusion (start at 2-20mcg/min)
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Aggressive fluid resuscitation (may require several litres)
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Bronchospasm: salbutamol PRN
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Give secondary medications:
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H1 antagonist: diphenhydramine 25-50mg IV
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H2 antagonist: ranitidine 50mg IV
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Methylprednisolone 1-2mg/kg IV per day OR dexamethasone 20mg IV
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Start invasive lines: arterial line, central line
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Refractory hypotension despite epinephrine:
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Vasopressin 1-40 unit bolus, 0.01-0.04 units/min infusion
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Glucagon 1-2 mg over 5 min IV then 5-15 mcg/min IV infusion (especially for patients taking beta blockers; inotropic & chronotropic effects not mediated through beta receptors)
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Methylene blue 1-2mg/kg IV (inhibits nitric oxide synthase & guanylate cyclase)
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Consider bicarbonate (0.5-1 mEq/kg) with acidosis
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Consider transesophageal echocardiography (TEE) & entertain other differential diagnosis
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Post-event care:
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Laboratory tests to support diagnosis:
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Serum tryptase levels 15 minutes and 3 hours after onset of symptoms
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Serum histamine levels peak 5 - 15 minutes after onset of symptoms; return to baseline at 60 minutes
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Discharge to ICU intubated & ventilated
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Due to biphasic nature, monitor at least 24 hours
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Consult allergist
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