title: Severe methemoglobinemia after transesophageal echocardiography.
abstract: Methemoglobinemia, an increased concentration of methemoglobin in the blood, is an altered state of hemoglobin whereby the ferrous form of iron is oxidized to the ferric state, rendering the heme moiety incapable of carrying oxygen. This can cause hypoxia, cyanosis, or even death. Severe methemoglobinemia resulting from oral benzocaine spray before endoscopic procedures has been reported as a rare complication. We report a case of severe acquired methemoglobinemia resulting from topical benzocaine use before transesophageal echocardiography. This case serves to highlight the severity of methemoglobinemia that can result from an otherwise innocuous agent even in small doses and the fact that prompt recognition and treatment of this disorder can be lifesaving.
authors.affiliation: Department of Cardiology, Mount Sinai Hospital, Chicago, IL 60608, USA. vvidyarthi@yahoo.com
authors.forename: Vasundhara
authors.initials: V
authors.lastname: Vidyarthi
authors.forename: Ravinder
authors.initials: R
authors.lastname: Manda
authors.forename: Aziz
authors.initials: A
authors.lastname: Ahmed
authors.forename: Sandeep
authors.initials: S
authors.lastname: Khosla
authors.forename: David L
authors.initials: DL
authors.lastname: Lubell
mesh_terms: D000336:Aerosols; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects*; D001566:Benzocaine / Q000008:administration & dosage / Q000009:adverse effects*; D003328:Coronary Thrombosis / Q000000981:diagnostic imaging; D017548:Echocardiography, Transesophageal / Q000379:methods*; D006801:Humans; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced*; D008751:Methylene Blue / Q000627:therapeutic use; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D000336:Aerosols; D000779:Anesthetics, Local; D008751:Methylene Blue; D001566:Benzocaine