title: Rapid Drink Challenge in high-resolution manometry: an adjunctive test for detection of esophageal motility disorders.
abstract: OBJECTIVE
  The Chicago Classification for diagnosis of esophageal motility disorders by high-resolution manometry (HRM) is based on single water swallows (SWS). Emerging data suggest that a "Rapid Drink Challenge" (RDC) increases sensitivity for motility disorders. This study establishes normal values and diagnostic thresholds for RDC in clinical practice.
  
  
  METHODS
  Two cohort studies were performed in patients with dysphagia or reflux symptoms (development and validation sets). Healthy subjects and patient controls provided reference values. Ten SWS and two 200-mL RDC were performed. Primary diagnosis for SWS was established by the Chicago Classification. Abnormal RDC was defined by impaired esophagogastric junction (EGJ) function (elevated integrated relaxation pressure during RDC [IRP-RDC]); incomplete inhibition of contractility during and ineffective contraction after RDC. Diagnostic thresholds identified in the development set were prospectively tested in the validation set.
  
  
  RESULTS
  Normal values were determined in healthy (n=95; age 37.8 ± 12) and patient controls (n=44; age 46.4 ± 15). Development and validation sets included 178 (54 ± 17 years) and 226 (53 ± 16 years) patients, respectively. Integrated relaxation pressure during RDC was higher for SWS than RDC in all groups (overall P<.001), except achalasia. Rapid Drink Challenge suppressed contractility, except in achalasia type III, spasm, and hypercontractile motility disorders (P<.001). An effective after-contraction was present more often in health than disease (P<.001). Optimal diagnostic thresholds identified in the development set (IRP-RDC ≥12 mmHg achalasia, IRP-RDC ≥ 8mmHg "all cause" EGJ dysfunction), were confirmed in the validation set (both, sensitivity ~85%, specificity >95%).
  
  
  CONCLUSIONS
  Rapid Drink Challenge contributes clinically relevant information to routine HRM studies, especially in patients with EGJ dysfunction.
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.|Department of Gastroenterology, Changi General Hospital, Singapore City, Singapore.
authors.forename: D
authors.initials: D
authors.lastname: Ang
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Hollenstein
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Misselwitz
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: K
authors.initials: K
authors.lastname: Knowles
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: J
authors.initials: J
authors.lastname: Wright
authors.affiliation: NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: E
authors.initials: E
authors.lastname: Tucker
authors.affiliation: Upper GI Physiology, University College London Hospital, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Sweis
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.|NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals, Nottingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Fox
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D060766:Drinking Water / Q000008:administration & dosage*; D015154:Esophageal Motility Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000379:methods*; D008875:Middle Aged; D013997:Time Factors
chemical_list: D060766:Drinking Water
keywords: Rapid Drink Challenge; diagnostic classification; esophageal motility disorders; high-resolution manometry; multiple water swallows; prospective cohort study