The effect of topical pharyngeal anesthesia on esophageal motility

A strong gag reflex may be a limiting factor to perform esophageal motility in some patients. Even though local anesthetics could alleviate such a problem, they are not used for fear of interfering with various manometric parameters. In this study, we evaluated the effect of topical pharyngeal local anesthesia on lower esophageal sphincter pressure, amplitude, duration, and velocity of esophageal contractions. We also studied its effects on the patient's tolerance. Esophageal motility was performed before and after topical anesthesia with 20% benzocaine. The baseline tracing and the tracing obtained after topical anesthesia were number coded and separated. They were evaluated blindly as to the pressure in the lower esophageal sphincter, amplitude, duration, and velocity of esophageal contractions. An average of 10 wet swallows was used to determine the above values. There was no significant change in the lower esophageal sphincter pressure or the amplitude of esophageal contractions after benzocaine. Similarly, there was no change in the duration or velocity of peristaltic activity. The patient's tolerance to the tube was unchanged or improved in 12 of 14 patients. Six patients had some difficulty in swallowing, but were able to compensate by sucking on the syringe. Our results indicate that topical pharyngeal anesthesia does not affect the usually measured manometric parameters; and while it may improve the patient's tolerance to the manometric catheter, it interferes with the ability to swallow.