SHM Converge Scientific Abstract ePoster Gallery-The Double-Edged Needle of Intravenous Epinephrine in Anaphylaxis

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This case report describes a 48-year-old woman with a history of multiple anaphylactic allergies who developed severe, refractory anaphylaxis after eating a new cracker flavor. She quickly developed dysphonia, dysphagia, and difficulty managing secretions. Despite self-administering two 0.3 mg intramuscular epinephrine doses, her symptoms worsened, making this the first time her usual treatment failed.<br /><br />In the emergency department, she received IV diphenhydramine before arrival, then dexamethasone, famotidine, and a 0.5 mg IV epinephrine bolus. Because her airway edema persisted, she was started on IV fluids and a continuous epinephrine infusion at 0.03 mcg/kg/min. ENT evaluation showed right arytenoid swelling and approximately 50% glottic airway closure. With continuous IV epinephrine, her edema and symptoms gradually resolved.<br /><br />The report also highlights cardiac effects during treatment. Her initial EKG showed a normal QTc of 408 ms, but three hours after starting the epinephrine drip, the QTc was reported as markedly prolonged at 628 ms. Although this may have reflected T-wave changes rather than true QT prolongation, the team responded by holding other QT-prolonging medications (hydroxychloroquine and venlafaxine), placing her on telemetry, and weaning off epinephrine as soon as symptoms improved. A repeat EKG 24 hours later showed QTc normalization to 443 ms.<br /><br />The authors conclude that while intramuscular epinephrine remains standard for most anaphylaxis, continuous IV epinephrine is an appropriate early option in refractory cases. However, because epinephrine may contribute to QT prolongation and arrhythmia risk, patients should be closely monitored with telemetry, avoidance of other QT-prolonging drugs, and prompt discontinuation of epinephrine once clinically safe.

Asset Subtitle

Richard Wang

Meta Tag

Author List Ashwini Niranjan-Azadi, Divya Rayapati, Jenna A. Milstein, Richard Wang

Category Clinical Vignettes

Concept Anaphylactic Shock

Concept Refractory Anaphylaxis

Concept Intramuscular Epinephrine

Concept Epinephrine Infusion

Concept Antipsychotic-Induced QT Prolongation

Distinguished Non-Finalist

Presenter Organization Johns Hopkins University School of Medicine

Presenting Author Richard Wang

Track Adult

Keywords

anaphylaxis

refractory anaphylaxis

epinephrine infusion

QT prolongation

airway edema

glottic closure

laryngeal edema

intramuscular epinephrine failure

telemetry monitoring

allergic reaction

Anaphylactic Shock

Refractory Anaphylaxis

Intramuscular Epinephrine

Epinephrine Infusion

Antipsychotic-Induced QT Prolongation