Effect of pneumoperitoneum and Trendelenburg position on gastro-oesophageal reflux and lower oesophageal sphincter pressure.

We have measured the effect of pneumoperitoneum and the Trendelenburg position on lower oesophageal sphincter (LOSP) and barrier pressures (BrP) in 11 anaesthetized pigs while measuring the incidence of gastro-oesophageal reflux with a pH electrode. Propofol in combination with sufentanil had no effect on LOSP or BrP. Adoption of the Trendelenburg position with a pneumoperitoneum of 15 mm Hg resulted in a significant increase in LOSP (P < 0.002) and BrP (P < 0.001). However, in two of 11 pigs who had the lowest LOSP before induction, there was regurgitation.