Hypopharyngeal pH monitoring artifact in detection of laryngopharyngeal reflux.
Hypopharyngeal pH artifacts have been a concern in the detection of laryngopharyngeal reflux. Our purpose was to analyze and quantify artifacts from dual-sensor hypopharyngeal pH monitoring. In all, 42 hypopharyngeal and 58 esophageal pH studies were reviewed. Type 1 (out of range), type 2 (pH drift), and type 3 (isolated pH drop) artifacts were identified. The proportion of proximal-sensor pH drop to <4 that was artifactual was determined. The median number (range) of artifacts was 1 (0-17) and 2 (0-28) for hypopharyngeal and esophageal pH studies, respectively (P = NS). The median proportion of artifactual pH drop to <4 was 1% (0-84%) and 2% (0-74%) for hypopharyngeal and esophageal pH studies, respectively (P = NS). The diagnosis did not change in any patient after excluding pH artifacts. In all, 19% of the combined 2,432 hypopharyngeal pH drops of <4 were artifacts. In conclusion, hypopharyngeal pH artifacts per study were uncommon but can be prominent in a few patients. One can identify these artifacts and exclude them from analysis.
Wo
John M
JM
Division of Gastroenterology/Hepatology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA.
Jabbar
Abdul
A
Winstead
Welby
W
Goudy
Steve
S
Cacchione
Robert
R
Allen
Jeff W
JW
D016477:Artifacts; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007013:Hypopharynx; D018670:Monitoring, Ambulatory; D010608:Pharyngeal Diseases / Q000175:diagnosis*; D012189:Retrospective Studies