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What is Investigation to diagnosis of laryngopharyngeal reflux and explain in detail?
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