Tracheal pH monitoring: a pilot study in tracheostomy dependent children

1. Determine the feasibility of measuring tracheal pH with a novel non-aqueous probe designed for oropharyngeal pH monitoring. 2. Correlate clinical and subclinical laryngopharyngeal reflux aspiration events with esophageal pH measurements.

Five children with chronic indwelling tracheostomies undergoing routine endoscopy and pH probe monitoring at a tertiary care pediatric aerodigestive center between October 2007 and January 2008 were identified for this prospective feasibility pilot study. The non-aqueous Restech Dx-pH probe was subsequently affixed to each child's tracheostomy with the probe tip confirmed to be within the tracheal lumen. Esophageal and tracheal probe pH measurements were subsequently recorded until the child was unable to tolerate the study or 24 h elapsed. Tracheal pH tracings were compared directly to esophageal pH tracings. Esophageal biopsy and bronchoalveolar lavage data were reviewed for each child.

3/5 children tolerated the tracheal probe for greater than 18 h. Adequate tracheal pH tracings were demonstrated for all children while the probe was in position. Mean baseline tracheal pH was 7.8. One child demonstrated direct correlation between acidic esophageal reflux events and decreased tracheal pH. Esophageal biopsy confirmed the presence of active inflammation consistent with reflux in this child.

Tracheal pH can be accurately recorded with the Restech Dx-pH probe. The technology may allow further investigations to determine the impact of gastroesophageal refluxate aspiration and empiric antireflux therapy in children with aerodigestive symptoms.