Unexplained Methemoglobinemia in Coronavirus Disease 2019: A Case Report

Abstract

Methemoglobinemia is a rare disorder of the blood in which there is an increase in methemoglobin, which occurs when hemoglobin is present in the oxidized form. Methemoglobin impairs hemoglobin’s ability to transport oxygen, produces functional anemia, and leads to tissue hypoxia. We report the successful management of a case of refractory hypoxia due to acutely acquired methemoglobinemia in a patient undergoing treatment for coronavirus disease 2019 (COVID-19) pneumonia. The cause of methemoglobinemia in this patient remains unknown. Hypoxia and methemoglobinemia did not respond to methylene blue and required administration of packed red blood cell transfusions.

The Role of Methemoglobin and Carboxyhemoglobin in COVID-19: A Review

“…The study selection process is shown in Figure 1a. For the case of COHb and COVID-19, 73 articles were retrieved from PubMed (n = 1) and Google Scholar (n = 72), one duplicate was removed and 68 articles were excluded after abstract review, leading to three articles that were finally included in the present study [20,24,25]. The study selection process is shown in Figure 1b…”

“…Based on the inclusion and exclusion criteria, seven duplicates were removed and 187 articles were excluded after abstract review. After the full set of remaining articles was screened, seven reports were finally included in the present study [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The study selection process is shown in Figure 1 a.…”

“…From the seven studies included in this review for the case of MetHb and COVID-19, two were cross-sectional studies [ 19 , 21 ] and five case reports [ 17 , 18 , 20 , 22 , 23 ]. The case descriptions reported findings of one single patient [ 17 , 20 , 22 , 23 ] or three patients [ 18 ]. Five studies were published in journals [ 17 , 18 , 20 , 21 , 22 ] and two on the preprint server medRxiv (medrxiv.org) [ 19 , 23 ].…”

“…The case descriptions reported findings of one single patient [ 17 , 20 , 22 , 23 ] or three patients [ 18 ]. Five studies were published in journals [ 17 , 18 , 20 , 21 , 22 ] and two on the preprint server medRxiv (medrxiv.org) [ 19 , 23 ].…”

“…For the case of the three studies concerning COHb and COVID-19, two were cross sectional studies [ 24 , 25 ] and one a case report [ 20 ]. Two of the studies were published in journals [ 20 , 25 ] and one on the preprint server Research Square (researchsquare.com) [ 24 ].…”