Abstract 19175: Anaphylaxis After Alteplase During Treatment of Pulmonary Embolism

Abstract

Introduction: Anaphylaxis is a rare complication to alteplase, a recombinant tissue plasminogen activator (tPA), during administration for pulmonary embolism (PE). Case Presentation: A 72-year-old male with a history of necrotizing fasciitis, recent below the knee amputation, and concern for metastatic melanoma had been undergoing treatment for an acute DVT with apixaban when he presented with an extensive saddle pulmonary embolism. He was evaluated by a Pulmonary Embolism Response Team (PERT) and classified as high risk (sPESI 2, new right ventricular dysfunction, and hypoxemia) and treated with 50 mg alteplase over two hours. At the end of his infusion, he experienced worsening hypoxemia and sudden hypotension treated with fluid resuscitation and an epinephrine infusion. Hemodynamic instability was thought to be secondary to obstructive shock so an additional 50 mg of alteplase was ordered. After the initial bolus of 10 mg alteplase, the patient demonstrated signs of anaphylaxis. He was initially treated with epinephrine, diphenhydramine, famotidine, methylprednisolone, and lactated ringers for the anaphylactic shock. The patient eventually required the addition of norepinephrine, vasopressin, and methylene blue for resolution of the shock. No additional alteplase was administered and a heparin infusion was resumed for treatment of the pulmonary embolism. He was ultimately successfully weaned off vasopressors and oxygen support with resolution of the pulmonary embolism. Discussion: Cardiac critical care providers should monitor for signs of anaphylaxis when using tPA in the management of PE. The main intervention of anaphylactic shock is administration of epinephrine. Updated guidelines recommend use of intramuscular epinephrine in the setting of anaphylaxis.