ESOPHAGEAL CONTRACTILITY DURING TOTAL IV ANESTHESIA WITH AND WITHOUT GLYCOPYRRONIUM

Somatic movement and spontaneous and provoked oesophageal contractions were noted at time of incision in 51 patients receiving total i.v. anaesthesia with alfentanil and propofol. Probit analysis of the dose of propofol required to prevent spontaneous movement revealed an ED50 (95% confidence limits) of 2.5 (1.8-2.9) mg kg-1 h-1 and ED95 of 4.7 (4.0-7.5) mg kg-1 h-1. Corresponding venous blood concentrations gave an EC50 of 1.2 (0.4-1.6) mu-g ml-1 and an EC95 of 4.0 (2.8-18.5) mu-g ml-1. ED50 of propofol for preventing spontaneous oesophageal contraction was 3.0 (1.9-3.6) mg kg-1 h-1. ED95 was 6.9 (5.0-27.3) mg kg-1 h-1; EC50 for oesophageal contractions was 1.7 (0.7-2.3) mu-g ml-1 and EC95 was 5.9 (3.7-70.6) mu-g ml-1. Another group of 10 patients were given glycopyrronium 5-mu-g kg-1 at induction; oesophageal contractility was significantly reduced in this group.