Acquired methemoglobinemia: A systematic review of reported cases.
Transfus Apher Sci
; 61(2): 103299, 2022 Apr.
Article
em En
| MEDLINE
| ID: mdl-34740513
ABSTRACT
INTRODUCTION:
Acquired methemoglobinemia may cause cyanosis and tissue ischemia unresponsive to oxygen supplementation.METHODS:
We performed a literature search to identify cases of acquired methemoglobinemia published between 1980 and 2020. Clinical, diagnostic, and treatment details were extracted from eligible cases.RESULTS:
A total of 76 reports involving 87 cases were analyzed. The median age at presentation was 32.5 with male to female ratio of 1.6. Cyanosis and SpO2 <90 % were reported in 82 % and 60 % of cases, respectively. Dapsone or cocaine-based anesthetics were causative in 52 % of cases; most anesthetic-related cases occurred in the peri-procedural setting. Methylene blue (MB) and red cell transfusion were given in 71 % and 10 % of cases, respectively. Compared to MB untreated patients, MB treated patients were more likely to be cyanotic (91.9 % vs 54.2 %), had higher proportions (%) and levels (g/dL) of methemoglobin (MetHb) - 33.2 % vs 15.3 % and 3.1â¯g/dL vs 1.2â¯g/dL, respectively. We found that among cyanotic cases, the median MetHb level was 3.0â¯g/dL (0.4-12.3â¯g/dL) with 74 % of values ≥ 1.5â¯g/dL. An SaO2SpO2 ratio of >1 was not universally present, but always coincided with an [SaO2-SpO2] delta value greater than zero.CONCLUSIONS:
Cyanosis and hypoxemia were not universal findings of acquired methemoglobinemia in our series. In addition, not all patients had cyanosis at MetHb ≥ 1.5â¯g/dL or an SaO2SpO2 ratio of >1. All those with an SaO2SpO2 >1 did, however, have a delta value greater than zero - a finding not previously reported which we feel holds diagnostic value.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Metemoglobinemia
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
/
Systematic_reviews
Limite:
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article