The pharmacological effect of omeprazole on water gastric emptying: A study based on an impedance measure

The present study was performed to validate the accuracy of a self-designed applied-potential tomograph (APT) in measuring the cross area of a studied object and to assess the effect of omeprazole premedication on water gastr ic emptying (GE), based on APT. Twelve electrodes were evenly placed in a c ircular array around the studied subjects. Ten electrodes in a rotated orde r recorded the electrical current injected into paired electrodes. Based on tomography, averaged signals of changed resistivity were constructed to di splay the area of interest and GE cu rye. Six beakers of various dia meters were respectively placed into a cylindrical perspex tank which was filled with saline to measure their cross areas via computer-generated diagrams of APT. One hour after either omeprazole (20 mg) or placebo premedication, 15 healthy males were ordered to consume 500 ml of test water to assess empty ing for 40 min. With in 3 days, a similar procedure was repeated using the counterpart premedication. The true cross areas of the 6 beakers are 2.01, 15.9, 18.8, 30.19, 38.48 and 63.61 cm(2), whereas those obtained by APT wer e 7.9 +/- 2.9, 16.7 +/- 3.3, 22.4 +/- 4.9, 28 +/- 4.8, 48.7 +/- 7.6 and 67 +/- 6.1 cm(2), respectively (r = 0.98, p < 0.001). Valid emptying data were obtained in 73.3 and 86.6% of subjects, following placebo and omeprazole, respectively (not significant). The half emptying times were 12.7 +/- 5.1 m in for the placebo-treated group and 10.5 +/- 3.6 min for the omeprazole-tr eated group, respectively (p < 0.05). The areas under the emptying curve we re 1,611.5 +/- 357.6 and 1,317.3 +/- 316.7 arbitrary units, respectively (p < 0.01). In conclusion, our APT system is accurate for large-area measurem ents; acid inhibition before APT measurement does not increase the success rate but enhances water emptying. The interpretation of impedance-obtained GE should consider the acid-inhibitory effect. Copyright (C) 2001 S. Karger AG, Basel.