Benzocaine-induced methemoglobinemia: experience from a high-volume transesophageal echocardiography laboratory.
Benzocaine (ethyl aminobenzoate), a topical anesthetic widely used before transesophageal echocardiography, has been reported to cause acquired methemoglobinemia. The incidence of benzocaine-induced methemoglobinemia in clinical practice, however, has been difficult to estimate. After systematic review of our institutional experience for clinically recognized cases of benzocaine-induced methemoglobinemia in patients undergoing transesophageal echocardiography, we report an estimated incidence of 0.115% (95% confidence interval 0.037-0.269). This report also provides the largest analysis of the incidence of methemoglobinemia in readministration cases. Although controversy remains as to whether this is an idiosyncratic versus dose-related response, a description of purported patient risk factors is included.
Novaro
Gian M
GM
Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, OH 44195, USA.
Aronow
Herbert D
HD
Militello
Michael A
MA
Garcia
Mario J
MJ
Sabik
Ellen Mayer
EM
D000328:Adult; D000368:Aged; D001566:Benzocaine / Q000009:adverse effects; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008708:Methemoglobinemia / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000453:epidemiology*; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors
D001566:Benzocaine