Synopsis of key/new findings
Gastroesophageal reflux disease (GERD) and LPR are caused by the reflux of gastric contents and mainly treated with PPI therapy despite some differences in the clinical presentation and treatment modalities.13 Most otolaryngologists prefer empirical PPI therapy during 1~3 months,14,15and patients with LPR are expected to respond to acid suppression therapy of sufficient dose and duration. However, PPIs would not be effective when nonacid components of refluxate lead to LPR.16 Alternative treatments, such as alginate and magaldrate, are recommended but are not as commonly used as PPI. Therefore, in this study, we analyzed reflux characteristics in patients with suspected LPR treated with high-dose PPIs twice for at least 2 months prospectively.
MII-pH monitoring is a more objective diagnostic tool compared to symptomatic or laryngeal tools for diagnosing LPR.17However, many otolaryngologists do not frequently use MII-pH because of patient inconvenience and lack of tolerance, unclear indications, and a perceived lack of benefit for LPR management.15Empirical PPI treatment without an objective diagnosis using 24-h MII-pH monitoring in patients with suspected LPR can lead to prolonged treatment, high cost, and refractory progression despite long-term treatment. The responder rates after treatment during 2 months and total medication periods were significantly higher in patients with LPR than in those with no reflux according to the all proximal reflux episodes in the 24-h MII-pH monitoring. The use of 24-h MII-pH monitoring in patients with suspected LPR could be an important tool, probably because of its cost effectiveness and provision of symptomatic relief compared to empirical PPI therapy.
In addition, MII-pH monitoring includes parameters to systematically identify reflux in patients with LPR. All reflux time, longest reflux time, and reflux type at the hypopharynx and lower esophageal sphincter can provide detailed information about the reflux, but there is no standard for interpreting these parameters. Thus, we aimed to identify parameters showing differences between patients with LPR responding well and those refractory to PPI therapy. In this study, patients with LPR responding well to PPI therapy showed higher values in proximal MII parameters compared to those with LPR refractory to PPI therapy although there were no significant differences in proximal reflux episodes between two groups.
Additionally, we hypothesized that the ROC curve might help find appropriate cut-off values of proximal all reflux time and proximal longest reflux time to predict responders with LPR. We compared sensitivity and specificity according to each cut-off value in the two ROC curves. The sensitivity plus specificity was higher for the cut-off value of proximal all reflux time than for that of proximal longest reflux time (1.317 vs. 1.291). Thus, the cut-off value (>0.000517%) of proximal all reflux time was an appropriate value to predict responders with LPR despite the low sensitivity (47.5%) in this study. We know that 0.000517% of 24 h is equivalent to 44.67 s. In other words, patients with LPR showing proximal all reflux time of more than 45 s can be expected to respond well to PPI therapy.