Chheda NN, Seybt MW, Schade RR, Postma GN. Ann Otol Rhinol Laryngol. 2009 Mar;118(3):166-71.
OBJECTIVES: We performed a prospective study of asymptomatic adult volunteers to establish normative values of pharyngeal pH using a novel pH probe.
RESULTS: The upper limits of normal (95th percentile) for the number of events below pH of 5.5, 5.0, 4.5, and 4.0 per 24-hour period were 16.6, 10.7, 7.4, and 0.2, respectively. The upper limits of normal (95th percentile) for an acid exposure time below pH of 5.5, 5.0, 4.5, and 4.0 per 24-hour period were 820 seconds, 385 seconds, 75 seconds, and 3 seconds, respectively.
CONCLUSION: Normative pharyngeal pH values are presented. Further studies are required to determine clinical relevance.