The effect of duodenojejunal alimentation on gastric pH and hormones in intensive care unit patients.

We evaluated effects of duodenojejunal (DJ) feeding on gastric pH and selected gastrointestinal hormones in 13 randomly selected patients in an intensive care unit (ICU). To obtain baseline values for gastric pH, a nasogastric (NG) tube was placed in each patient and gastric pH was measured every 30 minutes for 2 hours. To obtain control values, a Dobbhoff tube was placed fluoroscopically and 0.45 percent saline solution (NaCl), 75 ml, was infused for 1 hour and gastric pH was measured again; the previously placed NG tube was left in position. Then, by randomization, either 0.45 percent NaCl (pH = 5) was continued (n = 6) or a high-nitrogen, isotonic, enteral feeding solution (Osmolite HN, pH = 6.4) (n = 7) was infused, both at 75 ml/h. Gastric pH was noted hourly for 96 hours; antacid (Maalox TC, 15-ml aliquots) was given by NG tube when the pH was 4 or less. After 96 hours, the infusion was stopped and gastric pH was noted for 4 additional hours. Before and during initial saline solution infusion; after 24, 48, 72, and 96 hours of continuous infusion; and 4 hours after stopping the infusion, peripheral venous blood was obtained for measurement of plasma gastric inhibitory polypeptide (GIP) and serum gastrin. Data were analyzed by ANOVA (RMD), Fishers' exact test, and the unpaired t-test. Groups did not differ demographically. Throughout the infusion, gastric pH tended to be higher with the enteral feeding solution than with saline solution, but this was significant only at 24 hours. Less antacid was required with the enteral feeding solution at 24 and 48 hours than with saline solution. Plasma GIP levels were significantly higher with the enteral feeding solution than with saline solution during most of the infusion. Serum gastrin levels did not differ between the groups. In this cohort, infusion of the enteral feeding solution tended to maintain a gastric pH of more than 4 and was associated with increased plasma GIP levels, which may inhibit gastric acid secretion. Early enteral feeding may benefit certain ICU patients.