Systemic absorption and toxicity from topically administered lidocaine during transesophageal echocardiography.

This report describes the cases of three patients who had central nervous system toxicity from locally administered lidocaine during transesophageal echocardiography. Parenteral sedation was not employed. Serum levels of lidocaine were obtained after the procedure in all three patients, who recovered spontaneously and suffered no permanent ill effects. Medical conditions such as congestive heart failure and diminished hepatic function or concomitant use of lidocaine analogs may predispose patients to the toxic side effects of locally administered lidocaine. Extreme care and close monitoring of patients are warranted when topical lidocaine anesthetic is employed in the setting of delayed lidocaine clearance.