Qualitative assessment of esophageal pH recordings

Quantitative analysis of reflux episodes (the pH score) was used to diagnose pathologic reflux. The aim of the present study was to determine the pattern and significance of variables that may affect the pH scores. The quality of the first esophageal pH recordings were analysed and its effects on the pH scores as calculated by computer were determined. The most common abnormality 13/123 (10.6 per cent) was related to disconnection of the probe or the reference electrode from the pH meter resulting in falsely high pH scores. Abnormalities suggesting incorrect location of the probe occurred in 12/123 (9.7 per cent) resulting in falsely high or low pH scores. Finally, pH curve drift was found in 6 (4.9 per cent) of the recordings. It is concluded that the calculated pH score by computer may be misleading. Therefore, the quality of the pH recording should be determined before interpretation of pH measurement.