Methemoglobinemia induced by topical benzocaine: a warning for the endoscopist.

Abstract

Benzocaine is used routinely for topical pharyngeal anesthesia prior to upper endoscopy, to improve patient tolerance. A potentially fatal, although often unrecognized, complication of benzocaine use is methemoglobinemia. Here, we report a case of methemoglobinemia induced by benzocaine given before upper endoscopy. Rapid recognition of this complication and immediate treatment is essential to prevent complications related to significant tissue hypoxia. This case serves as an important reminder to physicians, especially endoscopists, about this serious side effect. Furthermore, we question the need for topical anesthesia for upper endoscopy in sedated patients.

• Authors: H Y Abdallah, S A Shah
• Journal: Endoscopy (Endoscopy) Vol. 34 Issue 9 Pg. 730-4 (Sep 2002) ISSN: 0013-726X [Print] Germany
• PMID: 12195332 (Publication Type: Case Reports, Journal Article)

Chemical References

• Anesthetics, Local
• Enzyme Inhibitors
• Methylene Blue
• Benzocaine

Topics

• Aged
• Anesthetics, Local (adverse effects)
• Benzocaine (adverse effects)
• Enzyme Inhibitors (therapeutic use)
• Esophagoscopy (adverse effects)
• Female
• Humans
• Methemoglobinemia (diagnosis, drug therapy, etiology)
• Methylene Blue (therapeutic use)
• Oximetry