1. Tracings of concurrent oesophageal manometry, pH, and impedance.
 Tracings of concurrent oesophageal manometry, pH, and impedance. Example of a “cough-reflux” sequence. The manometric tracing shows a cough burst consisting of phasic, short duration, rapid pressure rises occurring simultaneously and with the same pressure configuration at all manometric recording sites. The impedance tracing shows a retrogradely propagated drop consistent with liquid reflux and the oesophageal pH fell more than 1 pH unit but remained above 4 (weakly acidic reflux). Weakly acidic reflux occurred 0.8 seconds after the start of a cough burst.
D Sifrim et al. Gut 2005;54:
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