pH monitoring: is it the gold standard for the detection of gastroesophageal reflux disease?

Reproducibility of symptom association analysis in ambulatory reflux monitoring

INTRODUCTION

The temporal relationship between reflux symptoms and reflux episodes during ambulatory reflux monitoring can be studied with symptom association analysis, and the strength of the relationship can be expressed using indices such as the SAP (symptom association probability), SI (symptom index), and SSI (symptom sensitivity index). The reproducibility of these indices has not been determined yet.

METHOD

Twenty-one patients with typical reflux symptoms (9 men, 53 [38-57] yr) underwent two 24-h combined pH-impedance recordings off acid-secretory medication with an interval of 1-4 wk. The SAP, SI, and SSI were calculated for each measurement. Reproducibility of these indices was determined with Kendall's coefficients of concordance.

RESULTS

The number of reflux events were highly reproducible (Kendall W = 0.92, P < 0.01). The number of symptoms related to reflux events was reproducible (Kendall W = 0.91, P < 0.01) while the number of reported reflux symptoms was not (Kendall W = 0.75, P= 0.07). The SAP and SSI were highly reproducible (Kendall W = 0.90, P= 0.01, and W = 0.86, P < 0.05, respectively) but the SI was not (W = 0.73, P= 0.09). The percentage of patients with similar outcomes on two separate test days for the SAP, SI, and SSI was 86%, 67%, and 86%, respectively.

DISCUSSION

In 24-h pH-impedance recordings of patients with reflux symptoms, the number of reflux events and the number of symptoms related to reflux events were highly reproducible as were the SAP and SSI. This supports the use of these indices to express the relationship between symptoms and reflux episodes in clinical practice.

Color doppler in the diagnosis of the gastroesophageal reflux in children: comparison with pH measurements and B-mode ultrasound

Eighty-four high risk children were examined for suspected gastroesophageal reflux comparing 24-h esophageal pH measurements with ultrasound (US) scans with and without the use of color Doppler (CD). In 83.3 % of the patients there was unequivocal agreement (reflux or no reflux) among all three techniques; 60.7 % of the children showed reflux by pH-metry as compared to 51.2 % by B-mode US and 59.5 % by CD US. In 87 % of patients there was agreement between pH-metry and B-mode US as compared to 94 % between pH-metry and CD US. The sensitivity of reflux detection increased from 84.4 % to 98 % when CD was added to B-mode US. This improvement was thought to be due to the higher sensitivity of CD for rapid and small quantities of reflux. The small number of discrepancies between pH-metry and CD US is probably due to the inability of the former to detect neutral reflux of contents or short duration (< 30 s), while CD US may miss some cases of acid reflux due to the short time of the examination (10 min). The addition of CD increases the sensitivity of US for detecting reflux. This rapid, easy and reliable method can be used to screen high risk populations when reflux is thought to be the cause of respiratory symptoms.