Effect of Proton Pump Inhibitors on Gastric Juice Volume, Gastric pH and Gastric Intramucosal pH in Critically Ill Patients A Randomized, Double-Blind, Placebo-Controlled Study

Objective: This study aimed to determine the effect of administration of a single-dose proton pump inhibitor (PPI) on gastric intramucosal pH (pHi), gastric juice volume and gastric pH in critically ill patients. Methods: This prospective, randomized, double-blind, placebo-controlled study included 75 patients who were divided into five groups that received the following treatment: group C (n = 15), saline 100 mL; group 0 (n = 15), omeprazole 20 mg; group P (n = 15), pantoprazole 40 mg; group E (n = 15), esomeprazole 20 mg; and group R (n = 15), rabeprazole 20 mg. All treatments were administered nasogastrically in 100 mL of physiological saline. Measurements of gastric pHi, gastric juice volume and gastric pH were obtained immediately before and 2, 4 and 6 hours after administration of treatments. In addition, gastric content was aspirated and its volume was recorded. Results: Initial gastric pHi, gastric juice volume and gastric pH values were not statistically significantly different among the groups (p > 0.05). No statistically significant difference in gastric pHi was seen among the groups before or 2, 4 or 6 hours after saline or PPI administration. At hours 2, 4 and 6, gastric pH in the pantoprazole, esomeprazole and rabeprazole groups increased significantly, whereas gastric juice volume decreased significantly, compared with the omeprazole and placebo groups (p < 0.001). No statistically significant differences were seen between the pantoprazole, esomeprazole and rabeprazole groups. Conclusion: This is the first study to show that single-dose pantoprazole, esomeprazole and rabeprazole are associated with greater gastric pH increase and greater gastric juice volume decrease than omeprazole in critically ill patients. Our study also suggests that PPIs do not affect gastric pHi measurements in critically ill patients and can be administered during pH monitoring.