Inhibitory effect of prostaglandin E1 on gastric secretion during general anesthesia in humans

The present study was undertaken to clarify the effects of prostaglandin E1 (PGE1) on gastric secretion during general anesthesia. Thirty-three patients, 16 with (PGE1 group) and 17 without (control group) PGE1 administration, scheduled for selective surgery were studied during general anesthesia with nitrous oxide (67%) and enflurane (1%-2% inspired). PGE1 was administered at a rate of 50-200 ng·kg(-1)·min(-1) when hypotensive medication was required. In the PGE1 group, gastric juice was collected serially three times before and during administration and 60 min after discontinuation of PGE1. In the control group, it was collected three times corresponding to those in the PGE1 group. The pH of gastric juice increased significantly, and the acidity and pepsin activity decreased after the beginning of the administration of PGE1, and these changes were observed even 1h after discontinuation. There was significant differences in the pH, acidity, and pepsin activity between the two groups after administration of PGE1. The results indicate that PGE1 inhibits gastric secretion at doses that produce a sufficient hypotensive effect under general anesthesia.