Assessment of intragastric pH value changes after early nasogastric feeding

Studies have suggested that early feeding after injury decreases morbidity and mortality. Few reports, however, have focused on the change in pH inside the stomach after early tube feeding. The aim of the present study was the assessment of 1) the change in intragastric pH after surgery, and 2) the effect of early nasogastric tube feeding on intragastric pH value. From April 1997 to February 1998, 80 patients who underwent colon resection for colorectal cancer by a single surgeon entered the study and were randomized into four groups. Twenty patients (group I) were kept on NPO for 1 wk, and 20 patients per group (groups II, III, and IV) were fed through a nasogastric tube from the second to the seventh postoperative day with low-residual (Osmolite HN), high-fat (Pulmocare), and glutamine-containing (AlitraQ) enteral formulas. Feeding started at 500 kcal/500 cc/d. If the patient tolerated the formula well, feeding increased to 1500 kcal/1500 cc−1/d−1 the following day. Intragastric pH was measured preoperatively and then twice daily until the sixth postoperative day. The pH value of intragastric juice increased significantly once feeding started (3.67 ± 1.33 on the third postoperative day; 4.28 ± 1.26 on the six postoperative day). The pH value seemed only mildly affected by the patient’s tolerance for tube feeding (poorly tolerated group, pH 3.52 ± 1.75 versus 3.75 ± 1.21 in the well-tolerated group on the third postoperative day; poorly tolerated group, pH 3.67 ± 1.02 versus 4.45 ± 1.27 in the well-tolerated group on the sixth postoperative day). The pH value of intragastric juice was higher in group II than in groups III and IV (4.51 ± 1.57, 3.90 ± 1.20, 4.42 ± 0.89 respectively, on the sixth postoperative day). This series suggests that early nasogastric feeding can significantly elevate the intragastric pH value in patients after resection of colorectal cancer. Nasogastric feeding may decrease the incidence of stress ulceration by elevating the pH value of intragastric juice.