The role of nonacid reflux in laryngopharyngeal reflux diseases

Objective To analyze the role of nonacid reflux in laryngopharyngeal reflux diseases (LPRD). Methods From January 2014 to April 2019, 344 patients associated with LPRD underwent 24-h multichannel intraluminal impedance-pH monitoring, and their reflux symptom index (RSI) and reflux finding score (RFS) were recorded. The numbers of acid, weakly acidic and alkaline reflux events in the laryngopharynx were counted, and the consistency analysis of the results with the results of the RSI and RFS was conducted. Results Among the 344 patients, nonacid reflux events accounted for 74.1% (1367/1845) of the all reflux events. There were 111 patients with >= 3 acid reflux events, 218 patients with >= 3 any kinds of reflux events, and 257 patients with positive results of RSI or RFS. Taking the results of the RSI and or RFS as a reference, the sensitivity, specificity and consistency test Kappa value for the diagnosis of LPRD according to the existence of >= 3 acid reflux events were 41.2%, 94.2% and 0.228, respectively. With the existence of three or more all kinds of reflux events as the standard, the sensitivity, specificity and consistency test Kappa value were 76.7%, 74.7% and 0.449, respectively. Conclusion The nonacid reflux events account for the highest proportion of laryngopharyngeal reflux events, and the consistency of the results of RSI and or RFS with all reflux events is higher than that with only acid reflux events, that indicates nonacid reflux may play an important role in LPRD.