EFFECT OF TOPICAL ANESTHESIA ON ESOPHAGEAL SENSORY AND MOTOR FUNCTION IN HEALTHY-SUBJECTS

Oesophageal hyperalgesia was demonstrated in the non-cardiac chest pain syndrome and suggests an altered perception of visceral stimuli in these patients. Data on oesophageal sensory function and its pharmacological manipulation, however, are fragmentary. Using a randomized, double-blind, placebo-controlled cross-over design, ten healthy male volunteers were manometrically examined for the effects of topical oesophageal anaesthesia with benzocaine 0.75% on (1) oesophageal perception of graded intraluminal balloon distension, (2) oesophageal compliance and primary motility, and (3) rectal perception of graded intraluminal balloon distension. It was demonstrated that topical benzocaine significantly increased oesophageal perception thresholds for intraluminal distension (P < 0.03), irrespective of them being correlated to distension volume or distension pressure. The level of first sensation increased from 4.3 mi (SD 2.8) and 24.8 mmHg (SD 9.1) to 7.4 mi (SD 4.4) and 32.1 mmHg (SD 8.3), respectively; pain perception increased from 11.0 mi (SD 4.5) and 30.9 mmHg (SD 8.9) to 14.5 mi (SD 5.1) and 38.3 mmHg (SD 10.2), respectively In contrast, oesophageal compliance, primary oesophageal motility and rectal perception were nor altered. It was concluded that topical anaesthesia decreases visceral sensitivity of the oesophagus to mechanical distension by action on intramural nervous afferents. If does not affect oesophageal motor function, nor does it exert systemic analgesic effects.