The Impact of Prolonged pH Measurements on the Diagnosis of Gastroesophageal Reflux Disease: 4-Day Wireless pH Studies

Abstract

Increasing the duration of pH studies progressively improves measurement variance and the diagnostic reproducibility of reflux studies. Future studies must address the impact of prolonged pH studies on clinical management.

Patient acceptance and clinical impact of Bravo monitoring in patients with previous failed catheter‐based studies

“…categorical analysis) revealed that the prevalence of pathological acid exposure on at least one 24-h period during 48-h catheterfree pH monitoring was higher than that of the 24-h C-pH measurement. This is consistent with the studies by Pandolfino et al 1 and Scarpulla et al 6 that showed that analysis of the 'worst day' increases diagnostic sensitivity in prolonged pH monitoring. In contrast, if the diagnosis based on the average pH exposure over 48 h was compared with 24-h pH monitoring using normal values specific for both techniques (i.e.…”

“…), or with SI assessed during 24-h C-pH (P = N.S.). Thus, consistent with previous results, there was important day-to-day variability for oesophageal acid measurements or SI, 6,8 but no systematic difference over the measurement period was present.…”

“…17 Prolonged study duration reduces measurement variations, increases the number of 'events' available for analysis and improves test-retest reproducibilty. 6,8 It is important to note that this case series was not designed to address diagnostic yield of pH studies and it is not clear whether the 'average' or 'worst day' analysis of prolonged pH studies is most clinically relevant. 6 There are several possible explanations for the increased acid reflux observed in the Bravo group compared with the demographically and clinically similar C-pH group.…”

“…6,8 It is important to note that this case series was not designed to address diagnostic yield of pH studies and it is not clear whether the 'average' or 'worst day' analysis of prolonged pH studies is most clinically relevant. 6 There are several possible explanations for the increased acid reflux observed in the Bravo group compared with the demographically and clinically similar C-pH group. First, improved comfort and the lack of a catheter during Bravo pH measurement facilitate more normal dietary and physical activity.…”

“…Oesophageal pH data are then transmitted to a portable receiver attached to the patient's belt for 48 h. Prolonged measurement increases diagnostic reproducibility and is, therefore, most suitable in patients with intermittent symptoms in view of the wide day-to-day variability in symptom frequency. [6][7][8] It is less suitable for patients with prominent postprandial symptoms or for the investigation of patients on anti-secretory medication as most reflux events in these situations are weak or non-acidic. The catheter-free system is better tolerated than catheterbased pH measurement and is preferred by unselected patients referred for pH investigation.…”