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SESSION TITLE: Drug-Induced and Associated Critical Care Cases Posters 2 SESSION TYPE: Case Report Posters PRESENTED ON: 10/19/2022 12:45 pm - 01:45 pm INTRODUCTION: Methemoglobinemia is an increase in methemoglobin (mHb) level characterized by functional anemia and tissue hypoxia. It can be caused by congenital enzymes deficiencies, but it is usually acquired. Dapsone, an oxidizing agent, is a medication commonly associated with acquired methemoglobinemia (1). We describe the diagnosis and management of a COVID-19 patient with acquired methemoglobinemia due to Dapsone. CASE PRESENTATION: 84-year-old female with history of MPO-ANCA vasculitis with renal involvement, CKD4 and anemia of chronic disease presented with shortness of breath, lethargy and weakness. Initially, the patient was saturating (SpO2) 80% on room air and was placed on 4L nasal cannula (NC) with improvement to 92%. CT of the chest showed b/l GGOs consistent with atypical pneumonia and patient tested positive for COVID-19. About 4 months prior, she had received 2 doses of Rituximab and on high steroid therapy that was tapered to 5mg of prednisone daily. She has been on Trimethoprim/Sulfamethoxazole for PJP prophylaxis, but due to hyperkalemia the medication was stopped. After confirming no G6PD deficiency, she was started on Dapsone 100mg daily. During hospitalization, she was given dexamethasone 6 mg daily and Dapsone was continued. On hospital stay day 6, a rapid response was called after oxygen dropped to 78% while walking on 6L NC. She was placed on high flow NC 100% and SpO2 went up to 90%. An arterial blood gas (ABG) was then obtained showing pO2 of 334, oxyhemoglobin (oxyHb) of 83 and mHb of 17.4. The SpO2-PaO2 gap and elevated mHb lead to the diagnosis of Dapsone-induced methemoglobinemia. Dapsone was discontinued. Patient received a one-time dose of 1mg/kg IV of methylene blue. One hour later her dyspnea had improved and was on 3L NC. Repeat ABG showed improvement of oxyHb (98) and decreased mHb (2.2). DISCUSSION: Physiologically, mHb is less than 1% of total Hb (1) and occurs when the iron in the porphyrin group of heme is oxidized from ferrous to the ferric form (2). Ferric heme binds oxygen irreversibly causing a left shift of the oxygen-hemoglobin dissociation curve. Clinical presentation tends to correlate with mHb levels, and it varies from being asymptomatic to fatigue, dyspnea, confusion, seizure, cyanosis resistant to oxygen therapy (mHb > 15%) and death. Methylene blue is safe and can be consider when mHb level is greater than 10 to 20% (2). Methylene blue was administer to our patient given the presence of COVID (leaving patient more susceptible to medication-induced methemoglobinemia (3)) and chronic anemia which made her less likely to tolerate state of reduced oxygen delivery. CONCLUSIONS: The diagnosis of methemoglobinemia is a rare cause of hypoxemia that is often overlooked. In patients with risk factors (COVID, medication exposure) a high index of suspicion is needed when interpreting an ABG (SpO2-PaO2 gap) for correct diagnosis and appropriate treatment. Reference #1: Toker, Ibrahim, et al. "Methemoglobinemia Caused by Dapsone Overdose: Which Treatment Is Best?” Turkish Journal of Emergency Medicine, vol. 15, no. 4, Dec. 2015, pp. 182–184, 10.1016/j.tjem.2014.09.002. Accessed 31 Aug. 2020. Reference #2: Cortazzo JA, Lichtman AD. Methemoglobinemia: a review and recommendations for management. J Cardiothorac Vasc Anesth. 2014 Aug;28(4):1043-7. doi: 10.1053/j.jvca.2013.02.005. Epub 2013 Aug 13. PMID: 23953868. Reference #3: Naymagon, Leonard, et al. "The Emergence of Methemoglobinemia amidst the COVID -19 Pandemic.” American Journal of Hematology, vol. 95, no. 8, 3 June 2020, 10.1002/ajh.25868. Accessed 3 Mar. 2021. DISCLOSURES: No relevant relationships by Mileydis Alonso No relevant relationships by Samantha Gillenwater No relevant relationships by Christine Girard No relevant relationships by Sikandar Khan No relevant relationships by Jose Rivera No relevant relationships by Frederick Ross
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SESSION TITLE: Drug-Induced Lung Injury and Disease SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/18/2022 01:35 pm - 02:35 pm INTRODUCTION: COVID-19 has been notorious to cause "happy hypoxia” or presentation with profound hypoxia yet without proportional signs of respiratory distress. Methemoglobinemia is a rare and potentially life threatening condition characterized by an inability of hemoglobin to bind oxygen leading to diffuse tissue hypoxia. Diagnosis of methemoglobinemia in a patient with COVID-19 may be masked if the index of suspicion is low. We present such case of dapsone-induced methemoglobinemia in the setting of COVID-19. CASE PRESENTATION: A 64-year-old male presented to the hospital with fatigue. His past medical history included Type 1 Diabetes Mellitus (DM), hypertension and dermatitis herpetiformis. He also reported a 6 day history of testing positive for COVID-19 as an outpatient. His initial vital signs were stable and his peripheral oximeter showed a 96% saturation on 2L O2. Physical exam was unremarkable without any signs of respiratory distress. His labs were notable for blood glucose of 500, high anion gap metabolic acidosis concerning for diabetic ketoacidosis (DKA). A chest X-ray (CXR) revealed bilateral infiltrates. He was initiated on insulin drip and per hospital protocol initiated on Remdesevir and Decadron for COVID-19 treatment. Patient's DKA subsequently resolved. However on Day 4, patient's oxygen saturation decreased suddenly to the 80s without any signs of respiratory distress. Infectious workup including CBC, sputum culture, antigen for streptococcus, legionella returned negative. His CXR remained unchanged. Arterial blood gas (ABG) demonstrated pH of 7.45, pCo2 46mm Hg, pO2 157 mm Hg. Methemoglobin level was found to be 14.1%. He was given methylene blue 1 mg/kg and dapsone was discontinued. His methemoglobin level improved to 3.4% the next day. He was subsequently discharged home without need for supplemental oxygen. DISCUSSION: Methemoglobinemia can be acquired through drugs that oxidize the ferrous hemoglobin to ferric form. Dapsone is one such agent commonly used for dermatological conditions and opportunistic infection prophylaxis. The oxidative stress caused due to COVID-19 coupled with Dapsone use may have precipitated methemoglobinemia in our patient. Since the presentation can easily mimic "happy hypoxia", index of suspicion for methemoglobinemia can be low and thus can have profound consequences if undetected and not treated. CONCLUSIONS: In the setting of COVID-19 pneumonia with refractory hypoxemia, clinicians should have a high index of suspicion for methemoglobinemia especially in patients on highly oxidative medications. Reference #1: Burke P, et al. Dapsone-induced methemoglobinemia: case of the blue lady. Can Fam Physician. 2013 Sep;59(9):958-61. Reference #2: Naymagon L., Berwick S., Kessler A., et al. The emergence of methemoglobinemia amidst the COVID-19 pandemic. Am. J. Hematol. 2020;95: E196-E197 https://doi.org/10.1002/ajh.25868 Reference #3: Faisal H, Bloom A, Gaber AO. Unexplained Methemoglobinemia in Coronavirus Disease 2019: A Case Report. A&A Pract. 2020;14(9):e01287. doi:10.1213/XAA.0000000000001287 DISCLOSURES: No relevant relationships by Syed Azharuddin Speaker/Speaker's Bureau relationship with gsk Please note: 2020-present by Tariq Cheema, value=Honoraria Speaker/Speaker's Bureau relationship with GSK Please note: 2020 Added 04/14/2022 by Tariq Cheema, value=Honoraria Removed 04/14/2022 by Tariq Cheema Speaker/Speaker's Bureau relationship with BI Please note: 2020-PRESENT Added 04/14/2022 by Tariq Cheema, value=Honoraria Speaker/Speaker's Bureau relationship with astra zeneca Please note: 2020-Present Added 04/14/2022 by Tariq Cheema, value=Honoraria Speaker/Speaker's Bureau relationship with regeneron Please note: 2021-Present Added 04/14/2022 by Tariq Cheema, value=Honoraria No relevant relationships by Deeksha Ramanujam No relevant relationships by Alisha Sharma