Clinical Update Findings about pH-Impedance Monitoring Features in Laryngopharyngeal Reflux Patients

Purpose: The diagnosis of laryngopharyngeal reflux (LPR) is commonly based on non-specific symptoms and findings and a positive response to an empirical therapeutic trial. The therapeutic response is, however, unpredictable, and many patients need pH-impedance monitoring to confirm the diagnosis. Methods: A review of the recent literature was conducted in PubMED, Scopus, and Embase about the pH-study features of LPR patients. A summary of last evidence was proposed. Results: The awareness of otolaryngologists about indications and interpretation of pH-impedance monitoring is low. The hypopharyngeal-esophageal multichannel intraluminal impedance-pH monitoring (HEMII-pH) is the most reliable examination determining the type and composition of hypopharyngeal reflux events (HRE) and the LPR features. The use of HEMII-pH is important to confirm the diagnosis in selected patients because non-specificity of symptoms and findings. There are no international consensus guidelines for the LPR diagnosis at the HEMII-pH. However, most studies supported the occurrence of >1 acid/weakly acid/nonacid HRE as diagnostic threshold. HREs are more frequently gaseous, weakly/nonacid compared with reflux events of gastroesophageal reflux. HREs occurred as daytime and upright, which does not support the value of double proton pump inhibitors or bedtime alginate. Oropharyngeal pH-monitoring is another approach reporting different sensitivity and specificity outcomes from HEMII-pH. The use of Ryan score for the LPR diagnosis at the oropharyngeal pH monitoring may be controversial regarding the low consideration of alkaline HREs. Conclusions: The awareness of otolaryngologists about HEMII-pH indication, features, and interpretation is an important issue regarding the high prevalence of LPR in outpatients consulting in otolaryngology. The HEMII-pH findings may indicate a more personalized treatment considering type and occurrence time of HREs.