The Prevalence of Gastro-oesophageal Reflux in Chronic Lung Disease
Condition: Chronic Obstructive Pulmonary Disease; Bronchiectasis
MeSH terms: Gastroesophageal Reflux; Lung Diseases; Lung Diseases, Obstructive; Pulmonary Disease, Chronic Obstructive; Bronchiectasis
Study type: Observational

Summary: 
      Gastric reflux into the oesophagus may further lung damage in respiratory disease. The
      proportion of adults with chronic lung disease and gastric reflux is unknown. Adults with
      this disease regularly complete physiotherapy but the contribution of physiotherapy to reflux
      is unknown. This study will measure gastric reflux in adults with chronic lung disease, using
      24 hour acid monitoring. It is anticipated that approximately 50% of adults with chronic lung
      disease will have gastric reflux. After monitoring, the number of gastric reflux episodes
      will be calculated. The results will identify the extent of the gastric reflux problem in
      these patients and will enable appropriate medical treatment and modifications to
      physiotherapy, which may improve lung function and quality of life.
    

Detailed description: 
      Research plan:

      Fifty-four subjects will be recruited from the Department of AIRMED outpatient clinics at the
      Alfred Hospital, Melbourne. Subjects will be considered eligible if they have a diagnosis of
      COPD or bronchiectasis and are clinically stable.

      Subjects who give their consent will undergo the following measures:

        1. Demographic data including age, gender, BMI, prescribed medications at time of study.

        2. Structured symptom questionnaire A reliable, valid structured symptom questionnaire
           which will assess symptomatic GOR.

        3. Health -related quality of life and sleep quality Quality of life will be recorded using
           a Short form-36, St Georges's Respiratory Questionnaire and Quality of Life in Reflux
           and Dyspepsia questionnaire.

        4. Dual-channel 24 hour oesophageal pH monitoring

      Ambulatory 24 hour oesophageal pH monitoring will be undertaken by all subjects using
      dual-channel oesophageal pH monitoring equipment. The distal antimony-tipped probe will be
      sited 5cm above the upper portion of the lower oesophageal sphincter (distal sensor) with the
      proximal sensor sited 15cm above the distal sensor. The probe is attached to the digitrapper
      and will record oesophageal pH for 24 hours. The subject will be instructed to activate the
      digitrapper's three event buttons recording start and finish time of meals, supine versus
      upright posture and GOR symptoms. The following indices will be measured in the distal and
      proximal oesophagus:

        -  number of reflux episodes,

        -  % reflux time,

        -  number of long episodes > 5 minutes,

        -  duration of the longest episode

        -  DeMeester score, a weighted overall score of gastro-oesophageal function.

      All subjects will maintain a 24 hour diary recording meals, positions, medications and
      physiotherapy airway clearance sessions.

      During the 24 hour oesophageal pH monitoring, the following interventions will be completed:

        1. Standard Spirometry. Measurement of spirometry will be performed according to the GINA
           guidelines.

        2. Pepsin Assay. Four sets of samples per subject of sputum and saliva for pepsin analysis
           will be collected during the study: at study commencement, during the airway clearance
           session, upon rising in the morning and post exercise testing. EnzChek Protease Assay
           kit will be used for analysis.

        3. Airway clearance techniques. Each subject with excessive secretions will perform PEP
           therapy, completing 8 cycles of 10 breaths, 2 forced expirations (huffs) and coughing
           using a PariPEP device.

        4. Exercise testing. Each subject will complete 2 x Six-Minute-Walk Tests and 3 x Grocery
           Shelving Tests according to the test protocols.

        5. Actigraphy. Each subject will wear a wrist actigraph on their dominant wrist which will
           record timing of activity and inactivity, so that sleep quality can be extrapolated.
           Subjects will also complete a Pittsburgh Sleep Diary during the study.

      On study completion, subjects will return for removal of the oesophageal probe and retrieval
      of the digitrapper. Oesophageal pH study data will be downloaded onto a computer file for
      analysis. Oral intake, medications, symptoms, positioning, airway clearance and exercise will
      be extracted from subjective diaries that the subjects maintain, together with quality of
      life questionnaires and compared with pH recording data. Saliva and sputum pepsin assay
      results will be correlated with oesophageal pH monitoring data.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adults with COPD and bronchiectasis
      
Keywords: Gastro-oesophageal reflux; 24 hour oesophageal pH monitoring; Physiotherapy Airway clearance techniques; Exercise