Toxic methemoglobinemia after topical anesthesia for transesophageal echocardiography

J Am Soc Echocardiogr. 1996 Nov-Dec;9(6):874-6. doi: 10.1016/s0894-7317(96)90480-0.


Topical benzocaine spray is an anesthetic agent that is commonly used during transesophageal echocardiography (TEE). This agent is believed to be relatively safe because of very low systemic absorption. We report a case of toxic methemoglobinemia induced by benzocaine use for pharyngeal anesthesia during TEE. Physicians who perform TEE and use benzocaine or other topical anesthetics need to be familiar with this potential complication and have the necessary treatment readily available.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Anesthetics, Local / adverse effects*
  • Antidotes / therapeutic use
  • Benzocaine / adverse effects*
  • Echocardiography, Transesophageal*
  • Humans
  • Male
  • Methemoglobinemia / chemically induced*
  • Methylene Blue / therapeutic use


  • Anesthetics, Local
  • Antidotes
  • Methylene Blue
  • Benzocaine