Intra-Esophageal pH Monitoring on Two Consecutive Days in Patients With Gastroesophageal Reflux Symptoms

BACKGROUND: The best method to measure the frequency and duration of gastroesophageal reflux is 24-h pH or 24-h pH/impedance monitoring. However, the detection of reflux can vary when measured on different days. Our aim was to evaluate the possibility that the severity of gastroesophageal reflux is different even under similar conditions on two consecutive days. METHODS: We performed a 48-h pH monitoring in 12 subjects, aged 25 - 63 years, who complaint of heartburn and regurgitation, ten with esophagitis and two with non-erosive disease. The pH measurement was conducted at 5 cm from the lower esophageal sphincter. The patients stayed at the Clinical Investigation Ward of the hospital for 48 h. On each day, they consumed a 2,000 calorie diet. The results obtained on the first day were compared with those on the second day. RESULTS: Mean reflux index in the upright position was different between the two days. Results of the pH-monitoring within the 2 h after the meal revealed differences in the number of acidic reflux and reflux index episodes. Three patients had abnormal DeMeester score on one day and normal score on the other day. Considering the upper limit of 6.0% of the test duration with esophageal pH < 4 as indicative of gastroesophageal reflux disease, two patients showed abnormal results on one day and normal results on the other day. CONCLUSIONS: The 24-h pH monitoring, performed on two consecutive days under similar conditions, can lead to different diagnosis of gastroesophageal reflux disease in symptomatic patients.