Positioning of subject and of nasogastric tube during a gastric secretion study.

The histamine-infusion test was conducted in 50 subjects with a modification that allowed the completeness of recovery of the maximal gastric secretion to be assessed. The effects of the exact position of the tube and the position of the subject on the completeness of recovery were investigated. A simple water-recovery test was found to be as reliable as fluoroscopy for showing that the tip of the tube was within the stomach. Provided that the tip was within the stomach, the exact position of the tube did not affect recovery. Furthermore, recovery in 19 subjects was not appreciably affected by changing the person from the left lateral to the supine semirecumbent position.