Investigation to diagnosis of laryngopharyngeal reflux
pH monitoring at the level of pharynx is not helpful because the acid refluxed is neutralised by the pharyngeal secretions Hence a dual (bifurcated) catheter measuring both pH and impedance is used across upper oesophageal sphincter thereby permitting detection of pharyngeal reflux Ref: Shackelford 8th edition Pgno: 222
Esophageal pH monitoring
Dual probe impedance pH monitoring
Barium esophagram
Scintigraphy
Cardio thoracic surgery  