Table 3

Comparison of the Porto and the Lyon Consensus conclusions

Porto Consensus	Lyon Consensus
No discussion of endoscopy	Conclusive endoscopic criteria for GERD LA grade C or D oesophagitis; Biopsy-proven Barrett’s oesophagus; Peptic stricture.
Oesophageal impedance monitoring is the only recording method that can achieve high sensitivity for detection of all types of reflux episodes while pH monitoring is required for characterisation of reflux acidity. However, the role of impedance monitoring in the management of patients with GERD still needs to be defined.	pH-impedance monitoring is the gold standard for detection and characterisation of reflux episodes but is expensive, not widely available and interpretation is time consuming. When reflux monitoring is indicated on PPI, pH-impedance should be performed. When reflux monitoring is indicated off PPI, the choice between catheter-based pH-monitoring, wireless pH monitoring and pH-impedance monitoring is dependent on cost and availability.
No discussion of the conditions (off or on PPI) to perform reflux testing	Reflux monitoring is recommended off PPI in instances of ‘unproven’ GERD and on PPI in instances of ‘proven GERD’ (previous LA grade C or D oesophagitis, biopsy-proven Barrett’s oesophagus, peptic stricture or AET off PPI >6%).
No discussion of normal values	An AET <4% is normal and an AET >6% is abnormal (whatever the type of reflux monitoring and whether the study was performed off or on PPI).
No discussion of normal values	Reflux episodes >80/24 hours is abnormal and <40 is physiological on pH-impedance performed off or on PPI. Number of reflux episodes is an adjunctive metric to be used when AET is borderline or inconclusive.
Basal intraluminal impedance is abnormally low in patients with oesophageal mucosal abnormalities such as Barrett’s oesophagus or oesophagitis.	Measurement of baseline mucosal impedance (using either through the scope device or MNBI during ambulatory pH-impedance monitoring) is an adjunctive metric for the diagnosis of GERD.
No discussion of reflux-symptom association	A combination of a positive SI and positive SAP provides the best evidence of clinically relevant association between reflux episodes and symptoms.
Using manometry, common cavities occur during a higher proportion of reflux episodes in neonates and infants than in adults. No discussion of oesophageal motor function in GERD	Oesophageal high-resolution manometry is not useful for the direct diagnosis of GERD but can provide adjunctive information: to assess EGJ barrier function including its morphology (type I to III) and its vigour (using EGJ-CI); to evaluate oesophageal body motor function (intact, ineffective, fragmented or absent contractility) that correlates with oesophageal reflux burden; adjunctive tests should be included in the HRM protocol; to evaluate the contractile response (multiple rapid swallow); to evaluate EGJ obstruction (rapid drink challenge test).
Bilitec is a monitoring system that can detect duodeno-gastro-oesophageal reflux by using the optical properties of bilirubin.	Bilitec is no longer considered a reliable diagnostic tool for GERD and was not discussed.

AET, acid exposure time; EGJ-CI, o sophagogastric junction contractile integral; HRM, high-resolution manometry; PPI, proton pump inhibitors ; SAP, Symptom Association Probability; SI, Symptom Index.