Objectives: 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.
Study design: 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.