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

Oesophageal hyperalgesia was demonstrated in the non-cardiac chest pai n syndrome and suggests an altered perception of visceral stimuli in t hese patients. Data on oesophageal sensory function and its pharmacolo gical manipulation, however, are fragmentary. Using a randomized, doub le-blind, placebo-controlled cross-over design, ten healthy male volun teers were manometrically examined for the effects of topical oesophag eal anaesthesia with benzocaine 0.75% on (1) oesophageal perception of graded intraluminal balloon distension, (2) oesophageal compliance an d primary motility, and (3) rectal perception of graded intraluminal b alloon distension. It was demonstrated that topical benzocaine signifi cantly increased oesophageal perception thresholds for intraluminal di stension (P < 0.03), irrespective of them being correlated to distensi on volume or distension pressure. The level of first sensation increas ed 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 oe sophageal motility and rectal perception were nor altered. It was conc luded that topical anaesthesia decreases visceral sensitivity of the o esophagus to mechanical distension by action on intramural nervous aff erents. If does not affect oesophageal motor function, nor does it exe rt systemic analgesic effects.