title: Evaluation of gastroesophageal reflux in pediatric patients with asthma using impedance-pH monitoring.
abstract: OBJECTIVE
  To determine the proportion of acid and nonacid reflux events in children with asthma suspected to have gastroesophageal reflux (GER) using combined impedance-pH monitoring, and to determine the symptom index (SI) for nonacid and acid reflux events.
  
  
  METHODS
  This was a prospective study of children with asthma (age 5 months to 6 years) referred for evaluation of GER. Exclusion criteria were congenital anomalies, cerebral palsy, mental retardation, and cardiac disease. The children underwent a 20-hour multichannel intraluminal impedance (MII)-pH study.
  
  
  RESULTS
  A total of 24 children (17 male; mean age, 33 months) were enrolled from March 2004 to February 2005. MII-pH detected 1184 reflux events, versus 419 reflux events by pH alone; 51% (605 events) were nonacid. The proportion of nonacid reflux events decreased with time elapsed from last meal (P < .0001 by Pearson's chi2 test). A total of 555 symptoms were recorded, including 331 cases of cough, 243 of which (73.4%) were not associated with a reflux event. The SI for MII-pH was significantly different than that for the pH probe (37% vs 0%; P = .008).
  
  
  CONCLUSIONS
  Acid and nonacid reflux occurs with equal frequency in children with asthma. Most symptoms occur in the absence of a reflux event.
authors.affiliation: Pediatric Gastroenterology, Hepatology, and Nutrition Section and the General Clinical Research Center, Department of Pediatrics, Children's Hospital, University of Colorado Health Sciences Center, Denver, Colorado, USA.
authors.forename: Adria A
authors.initials: AA
authors.lastname: Condino
authors.forename: Judith
authors.initials: J
authors.lastname: Sondheimer
authors.forename: Zhaoxing
authors.initials: Z
authors.lastname: Pan
authors.forename: Jane
authors.initials: J
authors.lastname: Gralla
authors.forename: Darryl
authors.initials: D
authors.lastname: Perry
authors.forename: Judith A
authors.initials: JA
authors.lastname: O'Connor
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D002675:Child, Preschool; D003371:Cough / Q000175:diagnosis / Q000453:epidemiology; D017097:Electric Impedance; D005260:Female; D005744:Gastric Acid / Q000737:chemistry; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D010146:Pain / Q000175:diagnosis / Q000453:epidemiology; D011446:Prospective Studies; D013997:Time Factors