Table 1.

Risk of methemoglobinemia with various endoscopic procedures and topical anesthetics

Endoscopic procedure	Topical anesthetic spray used	Number of procedures	Cases of methemoglobinemia
Upper gastrointestinal endoscopy	4% lidocaine spray	21,767	0
Bronchoscopy	4% lidocaine spray	443	0
Transesophageal echocardiography	20% benzocaine spray	2,221	9 (0.40%)