A Validation Study of the Dx-pH Probe in Children for the Detection of Extra-oesophageal Reflux
Condition: Gastro-oesophageal Reflux
MeSH terms: Gastroesophageal Reflux; Esophagitis, Peptic
Study type: Interventional

Summary: 
      Gastro-oesophageal reflux (GORD) and its extraoesophageal manifestations present with a
      variety of symptoms in both adult and paediatric populations. In children the effects of
      refluxate above the upper oesophageal sphincter (UES) has been implicated as a contributory
      factor in the underlying pathological processes of a number of conditions including apnoea,
      asthma, chronic cough, subglottic stenosis, chronic rhinosinusitis and otitis media. The
      absence of typical symptoms in addition to the inability to obtain a formal symptom history
      from a young paediatric population contributes to the difficulty in establishing a diagnosis.
      At present there are no studies or data directly measuring extraoesophageal reflux and its
      correlation to oesophageal pH monitoring in children.

      The use of twenty-four hour oesophageal pH monitoring is regarded as the established
      technique for diagnosis of GORD, however this technique has been less reliable for detecting
      extra-oesophageal reflux. The investigators intend to use the Dx-pH Measurement system, a
      sensitive and minimally invasive transnasal device, to assess the feasibility and validate
      its use in a paediatric population.
    

Detailed description: 
      Gastro-oesophageal reflux (GORD) and its extraoesophageal manifestations present with a
      variety of symptoms in both adult and paediatric populations. In children the effects of
      refluxate above the upper oesophageal sphincter (UES) has been implicated as a contributory
      factor in the underlying pathological processes of a number of conditions including apnoea,
      asthma, chronic cough, subglottic stenosis, chronic rhinosinusitis and otitis media.

      The absence of typical symptoms in addition to the inability to obtain a formal symptom
      history from a young paediatric population contributes to the difficulty in establishing a
      diagnosis.

      At present there are no studies or data directly measuring extraoesophageal reflux and its
      correlation to oesophageal pH monitoring in children. As a result there is no baseline data
      for a paediatric population and subsequently no measureable definition of a significant
      extraoesophageal reflux event. There is a poor correlation between reflux events measured
      with an oesophageal probe and extra-oesophageal symptoms of reflux. Studies have demonstrated
      that 51% of patients without pharyngeal reflux had abnormal distal oesophageal pH studies.

      This is secondary to both technical concerns regarding the ability of such probes in
      detecting aerosolized and vapour forms of reflux in the pharynx and due to the inadequacy of
      the definition of a significant reflux event above the upper oesophageal sphincter. Moving
      cephaled (upwards) within the upper aerodigestive tract will result in shorter, higher pH
      events that may not be recognised using traditional oesophageal analysis, which define a pH<4
      as defining a significant oesophageal reflux event.

      The use of twenty-four hour oesophageal pH monitoring is regarded as the established
      technique for diagnosis of GORD, however this technique has been less reliable for detecting
      extra-oesophageal reflux.

      The Dx-pH Measurement system (Dx-pH; Respiratory Technology Corp., San Diego, CA) is a
      sensitive and minimally invasive transnasal device for detection of aerosolized
      extra-oesophageal acid reflux in the posterior oropharynx.

      The investigators intend to use the Dx-pH measurement system and the Peptest salivary pepsin
      assay (RBiomed, UK) in children already undergoing oesophageal pH studies. The investigators
      aim to assess the feasibility of these systems in a paediatric population,to provide baseline
      data and to validate its use in measuring extra-oesophageal reflux events in children. These
      results will be correlated against symptom questionnaire scores and the results of the 24
      hour oesophageal pH study results.

      The investigators' results will guide further interventional studies in this area, with the
      eventual aim of improving diagnosis and guided treatment for the extra-oesophageal
      manifestations of GORD
    

Intervention name(s): Experiemental diagnostic procedure: Dx-pH measurement system; Peptest assay; GORD symptom questionnaire
Intervention type(s): Device; Other; Other
Intervention description(s): The Dx-pH Measurement system (Dx-pH; Respiratory Technology Corp., San Diego, CA) is a sensitive and minimally invasive transnasal device for detection of aerosolized extra-oesophageal acid reflux in the posterior oropharynx.
The sterile single use Dx-pH catheter will be passed trans-nasally into the same nostril as the same nostril as the other catheter. The internal pH value of the oesophagus is then continuously measured and recorded onto a small ambulatory device. The 2 catheters are connected to the ambulatory recording devices and recording commences. The duration of the investigation is 24 hours.; A saliva sample of 0.5-1 ml will then be taken for pepsin assay (Peptest). The saliva sample will be drawn into a micro-centrifuge tube (0.5ml) and centrifuged. 80 microlitres is taken from the supernatant layer, vortex mixed, then applied to the assay test strip. The result is obtained after 15 minutes. The saliva sample will then be securely disposed.; A validated 7 domain GORD symptom questionnaire (GSQ-YC) to quantify the GORD related symptoms their child suffers with is to be completed prior to any intervention.
Other intervention name(s): (GSQ-YC)
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Gastro-oesophageal reflux; Children; Dx-pH Pharyngeal probe; GORD; Trans-nasal catheter