Fig. 1. Nutrient administration schedule (a: half-solid nutrient first and then pectin solution and liquid nutrient protocol for 5 patients, and b: pectin solution and liquid nutrient first and then a half-solid meal protocol for 5 patients). inhibitors and H2 receptor antagonists. In these 4 patients, 24-h esophageal MII-pH monitoring was performed after withdrawal of all anti-secretory drugs for 7 days in order to completely eliminate their influence. A 24-h esophageal monitoring study during PEG feeding was performed from 7:00 AM using a MII-pH system (Sandhill Scientific Inc., Highlands Ranch, CO). We used a 2.1- mm-diameter, combined MII-pH catheter (Sandhill Scientific Inc.) with six impedance and two (esophageal and gastric) anti- mony pH sensors with an external reference. Prior to the proce- dure, the pH sensors were calibrated using solution buffered at pH 4.0 and 7.0, as specified by the manufacturer. The probe was then inserted transnasally through the esophagus into the stomach, and the esophageal pH sensor was positioned 5 cm above the lower esophageal sphincter (LES) under X-ray fluoroscopy guid- ance. The design of the probe allowed measurement of impedance data at 3, 5, 7, 9, 15, and 17 cm above the LES. The catheter was connected to a data logger (Sleuth System; Sandhill Scientific Inc.) that stored data from the eight channels (6 impedance and 2 pH) with a frequency of 50 Hz. After insertion of the MII-pH catheter, conventionally employed liquid nutrient was injected as a breakfast. Half-solid nutrient for lunch and a combination of pectin solution and liquid nutrient for dinner were supplied through PEG tubing in 5 patients, and combined pectin solution and liquid nutrient for lunch and half- solid nutrient for dinner were supplied in the remaining 5 patients. In this study, we employed commercially available half-solid nutrients and liquid nutrients. The half-solid nutrient was 200 g of PGSOFT-EJ® (Terumo Corporation, Tokyo, Japan), and the liquid nutrient with pectin solution was 300 ml of K-LEC® (Kewpie Corporation, Tokyo, Japan). Total calories, protein, and lipids in K. Adachi et al. 200 g of PGSOFT-EJ® and 300 ml of K-LEC® are 300 kcal and 300 kcal, 12.0 g and 10.5 g, and 6.6 g and 9.9 g, respectively. The contents of several minerals and vitamins in the two nutrients were almost equal. The pectin solution was one pack of REF-P1® (Kewpie Corporation) for 300 ml of K-LEC®. One pack of REF- P1® weighs 90 g and the content includes 87.3 g of water, 2.5 g of pectin, 0.2 g of protein, 0.1 g of fat, 0.5 g of carbohydrate and 1.4 g of fiber, allowing easy infusion into the stomach using a syringe. The water volumes of PGSOFT-EJ® and the combination of K-LEC® and REF-P1® were markedly different (131 g vs 342 g). Total water administration was therefore adjusted to 400 g by modifying the volume of water administered with the nutrients, as described in Fig. 1. The viscosity of PGSOFT-EJ® is about 20000 mPas and that of the combination of K-LEC® and REF-P1® is about 1520 mPas, as detailed in the explanatory pamphlet supplied by each manufacturer. PGSOFT-EJ® and the combination of K-LEC® and REF-P1® were supplied to the patients in accor- dance with the schedule shown in Fig. 1. Two hundred and fifty millilitres of water was delivered via the PEG feeding tube during a 10-min period before administration of the half-solid nutrient. At 1 h after delivery of the water, the half-solid nutrient was delivered with 20 ml of water through the PEG tube during a 10-min period. The patients were instructed to remain supine, and the bed head was elevated to 30° for 2 h. For administration of the combination of pectin solution and liquid nutrient, 90 ml of REF-P1® was injected via the PEG feeding tube using a syringe, and 300 ml of the liquid nutrient was infused by drip infusion during a 1-h period, followed by delivery of 60 ml water during 10 min. Patients were instructed to remain supine, and the bed head was elevated to 30° for 2 h. J. Clin. Biochem. Nutr. | May 2012 | vol. 50 | no. 3 | 191 ©2012 JCBN