title: Methemoglobinemia misdiagnosed as ruptured ectopic pregnancy.
abstract: A 22-year-old woman with an initial diagnosis of 'ruptured ectopic pregnancy' and 'hemorrhagic shock' was sent to the operation room for surgical treatment. The mucocutaneous color was deeply cyanosed and the pulse oximeter oxygen saturation (SpO2) was only 86% after tracheal intubation (100% O2). 'Chocolate-brown' blood was observed and methemoglobinemia was considered. Then the arterial blood gas (ABG) sample was obtained, an intravenous infusion of methylene blue and vitamin C followed. The patient recovered quickly, and later two other patients with similar symptoms were treated in the same way. The success was due to a correct diagnosis accompanied with prompt treatment and quick recognition of the etiology.
authors.affiliation: Medical School of Nanjing University and Department of Anesthesiology, Jinling Hospital, Nanjing, China.
authors.forename: J J
authors.initials: JJ
authors.lastname: Yang
authors.forename: N
authors.initials: N
authors.lastname: Lin
authors.forename: R
authors.initials: R
authors.lastname: Lv
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: F
authors.initials: F
authors.lastname: Zhao
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: J G
authors.initials: JG
authors.lastname: Xu
mesh_terms: D000328:Adult; D000931:Antidotes / Q000627:therapeutic use; D000975:Antioxidants / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000627:therapeutic use; D001784:Blood Gas Analysis; D003937:Diagnosis, Differential; D005260:Female; D005520:Food Preservatives / Q000506:poisoning*; D006801:Humans; D008460:Meat / Q000506:poisoning*; D008708:Methemoglobinemia / Q000139:chemically induced / Q000175:diagnosis*; D008751:Methylene Blue / Q000627:therapeutic use; D009566:Nitrates / Q000506:poisoning*; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis*; D012421:Rupture; D012771:Shock, Hemorrhagic / Q000175:diagnosis; D012977:Sodium Nitrite / Q000506:poisoning*
chemical_list: D000931:Antidotes; D000975:Antioxidants; D005520:Food Preservatives; D009566:Nitrates; C031618:sodium nitrate; D012977:Sodium Nitrite; D001205:Ascorbic Acid; D010100:Oxygen; D008751:Methylene Blue