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.