The sensitivity of multichannel intraluminal impedance and the pH probe in the evaluation of gastroesophageal reflux in children.
OBJECTIVE
Multichannel intraluminal impedance (MII) has been incorporated into gastroesophageal reflux evaluations in children despite a lack of evidence comparing it to the gold standard pH probe. The aim of this study was to compare these two technologies.


METHODS
Twenty-five consecutive, untreated children undergoing pH-MII recording were studied. Sensitivities for the pH probe and MII were defined as: (acid+pH-only episodes)/(acid+non-acid+pH-only episodes) and (acid+non-acid episodes)/(acid+non-acid+pH-only episodes), respectively. Sensitivities were compared using paired t testing. After the analysis was performed, the pH-MII tracings of 25 age-matched children taking acid suppression therapy were compared and sensitivity calculations were performed.


RESULTS
In untreated patients, 1845 reflux episodes were detected, and 1702 were detected in treated patients. The mean sensitivities of pH probe and MII in untreated patients were 80.6 +/- 18.2% and 76.1 +/- 13.5%, respectively (P = .41). The mean sensitivities of pH probe and MII in treated patients were 47.2 +/- 36.0% and 80.3 +/- 21.1%, respectively (P = .005). Twenty-five percent of reflux episodes were pH-only episodes. There were no differences in the mean number of acid or non-acid reflux episodes in patients with normal and abnormal pH probe studies. Instead, there were significantly more pH-only episodes in patients with abnormal probe studies.


CONCLUSIONS
The sensitivity of MII equals that of the pH probe in untreated patients but is superior to the pH probe in treated patients. pH-only episodes are numerous in pediatrics and should be included in pH-MII analyses.
Rosen
Rachel
R
Center for Motility and Functional Gastrointestinal Disorders, Division of Gastroenterology and Nutrition, Children's Hospital-Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
Lord
Candace
C
Nurko
Samuel
S
D002648:Child; D017097:Electric Impedance; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D012680:Sensitivity and Specificity