Measurement of gastro-oesophageal reflux after antacid administration using a perfusion technique.

A study was carried out to measure gastro-oesophageal reflux in 6 asymptomatic and 9 heartburn subjects using a perfusion technique. Subjects swallowed a multi-lumen tube and the lower oesophageal sphincter pressure was measured. A phenol red solution was then infused through it into the stomach for 90 minutes whilst the oesophagus was aspirated continuously. The quantity of phenol red in oesophageal and gastric aspirates over 10-minutes periods was measured. In the heartburn subjects reflux was 1.27 +/- 0.37 ml/min and in the control subjects 0.23 +/- 0.07 ml/min, (p = 0.02). After 10 ml of an antacid combination, reflux in heartburn subjects was reduced to 0.59 +/- 0.18 ml/min and 0.68 +/- 0.16 ml/min in the second and third 30-minute period. Sphincter pressures increased from 8.9 to 11.8 mmHg. Control subjects showed little change in sphincter pressure or reflux after the antacid. Serum gastrin and secretin levels did not change in either group. This technique enables gastro-oesophageal flow rates to be easily measured. The results suggest that antacid administration tends to normalize lower oesophageal sphincter pressure and gastro-oesophageal reflux in patients with heartburn.