Benzocaine-induced methemoglobinemia during an outpatient procedure.
Outpatient transesophageal echocardiography was performed in a 69-year-old man with a history of aortic valve repair. During the procedure the patient became markedly cyanotic and hypotensive. Oxygen saturation measured by pulse oximetry decreased from 97% to the mid-80s. The man's condition continued to deteriorate. On transfer to a critical care unit, blood analysis by co-oximetry showed methemoglobin saturation of 67.8%. The patient's condition improved significantly after intravenous administration of methylene blue 1 mg/kg. With increasing numbers of outpatient procedures performed under topical anesthesia, measures should be in place to deal with a potential life-threatening adverse event such as methemoglobinemia.
Wurdeman
R L
RL
Creighton Cardiac Center, Omaha, Nebraska 68131, USA.
Mohiuddin
S M
SM
Holmberg
M J
MJ
Shalaby
A
A
D000368:Aged; D000779:Anesthetics, Local / Q000009:adverse effects*; D001566:Benzocaine / Q000009:adverse effects*; D017548:Echocardiography, Transesophageal; D006801:Humans; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced*; D010045:Outpatients
D000779:Anesthetics, Local; D001566:Benzocaine