Inter-reviewer Variability in Interpretation of pH-Impedance Studies: The Wingate Consensus

Novel impedance‐pH parameters are associated with proton pump inhibitor response in patients with inconclusive diagnosis of gastro‐oesophageal reflux disease according to Lyon Consensus

“…The present study was aimed at investigating the diagnostic yield of novel impedance-pH variables in either confirming or refuting the diagnosis of GERD in patients with an oesophageal acid exposure between 4% and 6% and evaluating their relationship with PPI response in these subjects with an inconclusive diagnosis of GERD according to Lyon Consensus criteria. Normative values for these parameters have been proposed in pilot investigations [15][16][17] but are still awaiting generalised validation since consensus rules for assessment of impedance-pH tracings have only recently been defined 28 and provisional data are currently available. 29 In agreement with several previous investigations, [13][14][15][16][17][18][19] we confirm that MNBI and PSPW index can increase the diagnostic yield of impedance-pH in patients with typical reflux syndrome.…”

The Value of Reflux Monitoring: The Old and the New for the Diagnosis and Assessment of GERD

“…This can be identified on pH-impedance tracings as a swallow occurring within 30 seconds of a reflux episode (PSPW), and the proportion of reflux episodes followed by PSPW is termed the PSPW index. 31,47 Earlier studies reported the PSPW index to be 76% to 80% ± 13 38,46,47 in healthy volunteers, and a threshold of 61% was reported to segregate GERD, especially lack of PPI response, from healthy individuals. 47,50 However, a recent study of 391 healthy individuals reported high variability of the PSPW index, with median values of 50%, and fifth percentile values of 15% to 19% in healthy subjects, indicating that this metric cannot be used as a stand-alone indicator of GERD.…”

“…1,10 However, pH-impedance studies require time and operator experience for accurate interpretation, as automated analysis overcounts particularly non-acidic reflux episodes. 31 Symptoms are considered to be associated with a reflux episode if they occur within 2 minutes of the reflux episode. 32,33 The symptom index (SI) is the proportion of symptoms associated with reflux episodes to all reflux episodes recorded, 34 and is considered abnormal if >50%.…”

Editorial: post‐reflux swallow‐induced peristaltic wave in eosinophilic oesophagitis—more questions than answers?

“…6 Finally, there remains significant inter-reviewer variability in identification and recording of both reflux episodes and PSPWs; the absolute PSPW count varies with reviewer opinion since automated software analysis is inaccurate for reflux episodes and non-existent for PSPW. 7,8 Questions regarding PSPW notwithstanding, Frazzoni et al bring up interesting concepts and further questions. They report a baseline impedance gradient (lower values distally) in patients with PPI-responsive EoE that coincides with GORD-like oesophageal pathophysiology, in contrast to patients with uniformly low panoesophageal baseline impedance values, 9 where PPIs did not help and PSPW-related delta pH was lower.…”