USE OF METHYLENE BLUE IN REFRACTORY ANAPHYLAXIS MAY PREVENT A CATASTROPHIC INTUBATION

Abstract

SESSION TITLE: Wednesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Anaphylaxis is a life-threatening condition that is primarily treated with epinephrine. The obesity epidemic is leading to new challenges in delivering care and considering non-conventional management is essential. We describe a case of a normotensive super-morbid patient with refractory anaphylaxis successfully treated with methylene blue. CASE PRESENTATION: A 23-year-old female with Down’s syndrome and morbid obesity presented to the emergency department in anaphylaxis after eating shrimp. Within 30 minutes of ingesting shrimp, patient developed significant swelling and difficulty breathing. On physical exam, BMI 71, blood pressure 125/71, pulse 95 and respiratory rate 36/minute. She has small mouth, large neck with tongue protruding outside her mouth, angioedema with grunting, loud audible stridor and diffuse pruritic hives. Intramuscularly, she received two epinephrine 0.3 mg, diphenhydramine 50 mg, methylprednisolone 125 mg along with inhaled racemic epinephrine & 2% nebulizer lidocaine. Due to her super-morbid obesity, there was significant concern for subcutaneous deposition of the aforementioned medications. Intravenous access was obtained and she was given only 0.1 mg epinephrine due to tachycardia and hypertension. Given her refractory anaphylaxis, worsening of tachycardia/dysrhythmia and in attempt to prevent a catastrophic intubation due to body habits, decision was made to administer methylene blue. We used 100 mg methylene blue, 1mg/kg of adjusted body weight, mixed in 100mL D5W administered over 20 minutes. Her angioedema visibly improved resulting in decreased work of breathing. Her stridor and drooling resolved. The intubation was prevented. DISCUSSION: Methylene blue is recommended by Joint Taskforce of American Academy of Allergy/Asthma/ Immunology for “anaphylaxis associated with hypotension” unresponsive to primary intervention. Platelet activating factor and histamines, significant contributors of anaphylaxis, are blocked by methylene blue via competitive inhibition of guanylate cyclase, preventing smooth muscle relaxation and vasodilation, therefore blocking the effects of nitric oxide. The management of life-threatening conditions such as anaphylaxis can offer a unique challenge in morbidly obese patients. Considering an alternative and safe treatment such as methylene blue can be life-saving. At this time, there remains no consensus regarding the dosage. CONCLUSIONS: Given the life-threatening, emergent circumstances of anaphylaxis and obesity epidemic leading to new challenges in delivering care, adjuvant management for refractory anaphylaxis is essential, particularly in high risk, difficult airway setting as seen in our patient. Methylene blue may be considered an alternative treatment option for morbidly obese patients with refractory anaphylaxis with or without hypotension to prevent intubation. Reference #1: Bauer CS, Vadas P. Methylene blue for the treatment of refractory anaphylaxis without hypotension. American Journal of Emergency Medicine (2013) 31, 264.e3–264.e5 Reference #2: Rodrigues JM, et al. Methylene blue for clinical anaphylaxis treatment: a case report. Sao Paulo Med J. 2007. DISCLOSURES: No relevant relationships by Kathleen Bryant, source=Web Response No relevant relationships by Lakshmi Kallur, source=Web Response No relevant relationships by Alexandra King, source=Web Response No relevant relationships by Jennifer Lindsey, source=Web Response No relevant relationships by Durga Pemmaraju, source=Web Response No relevant relationships by Kristopher Roach, source=Web Response No relevant relationships by Mitra Sahebazamani, source=Web Response