Symptom association analysis in ambulatory gastro-oesophageal reflux monitoring
- 1Department of Gastroenterology, St Antonius Hospital, Nieuwegein, the Netherlands
- 2Gastrointestinal Research Centre, University Medical Centre, Utrecht, the Netherlands
- Correspondence to:
Dr A J Bredenoord
Department of Gastroenterology, St Antonius Hospital, PO Box 2500, 3430 EM Nieuwegein, the Netherlands;
During the past three decades, prolonged monitoring of oesophageal pH has become increasingly popular among physicians. Most of the studies carried out with this technique focused on oesophageal acid exposure, defined as percentage of time with pH below 4. However, in most cases acid exposure variables are not very useful in the evaluation of patients with symptoms and signs of gastro-oesophageal reflux disease (GORD). An often neglected aspect of 24 hour pH recording is assessment of the temporal relation between reflux and symptoms. Various methods to quantify this relationship were developed. Here, we review these methods and the contribution of symptom association analysis to the evaluation of patients with symptoms suggestive of GORD.
The use of prolonged monitoring of oesophageal pH as a measure of gastro-oesophageal reflux was first described in 1969.1 More than a decade after its introduction as a hospital based technique for inpatients, oesophageal pH monitoring became rather popular when ambulatory data recorders became available.2 Most of the studies carried out with the technique focused on measurement of oesophageal acid exposure, defined as percentage of time with pH below 4, in patients with various manifestations of GORD. Later, the notion emerged that 24 hour pH recording also makes it possible to investigate the temporal relation between reflux and symptoms. In this review, we focus on the contribution of symptom association analysis to the evaluation of patients with symptoms suggestive of GORD and we discuss the various methods for symptom analysis that are currently used.
MEASUREMENT OF OESOPHAGEAL ACID EXPOSURE
Since the introduction of 24 hour oesophageal pH monitoring, numerous parameters have been proposed to provide a quantitative description of a patient’s pH profile. Simple (for example, number of reflux episodes, percentage of time with pH below 4, number of reflux episodes lasting more than five minutes) as well as composite …