Effect of Continuous Positive Airway Pressure (CPAP) on Lower Esophageal Sphincter Pressure in Morbidly Obese Patients
Condition: Sleep Apnea; Gastroesophageal Reflux Disease
MeSH terms: Gastroesophageal Reflux; Sleep Apnea Syndromes
Study type: Observational

Summary: 
      This trial is enrolling patients who are already being seen at OHSU weight loss clinic or
      have been referred for clinical reasons by their physician to the OHSU weight loss clinic and
      are going to have a esophageal manometry that would be paid for by their insurance company
      for clinical reasons.

      In patients undergoing weight loss surgery investigators plan to study the effect of
      continuous positive airway pressure during a esophageal manometry.
    

Detailed description: 
      Subjects will be invited to be in this research study because they are being considered for
      weight loss (bariatric) surgery that is being paid for by their insurance company. As part of
      the preparation for surgery, subjects will have a test called manometry that measures
      pressure in the esophagus (food pipe). For this test, a tube will be lowered down one nostril
      into the food pipe.

      Studies have shown that Continuous Positive Airway Pressure (CPAP) reduces reflux in people
      with or without sleep apnea as well as in people with reflux. The investigators are trying to
      understand how this occurs. This research study will add about 10 additional minutes to the
      clinic visit. The investigators expect about 50 subjects to be in the study at OHSU. Outcomes
      will be measured at 18 months.

      Patients scheduled for esophageal manometry and motility studies prior to their bariatric
      surgery will be given a study flyer at the bariatric clinic. A list of the patients who are
      interested in participating in the study will be given to one of the study investigators. A
      study investigator will call these patients to explain the study, assess their interest in
      participation, and review their eligibility for entrance into the study. Assessment of
      eligibility will be done by asking for medical history over the phone as well as by
      requesting access to their medical record to ensure the patients do not meet exclusion
      criteria. After review of the patient's clinical history verbally and through review of the
      medical record, informed consent will be signed at their manometry appointment.

      Subjects will undergo the manometry procedure. After finishing the procedure, when the
      catheter would normally be withdrawn after the procedure, it will remain in place for the
      study. A CPAP mask will be placed over the subject's nose. CPAP blows air in the nose with a
      mild pressure. The air pressure will be slowly increased while pressure in the esophagus is
      being recorded. As done with the regular manometry, the subject will be asked to swallow
      small amounts of water during the test. The test will be completed in 10 minutes. The CPAP
      and the tube will be removed.

      Subjects will complete a questionnaire prior to the manometry about gastrointestinal
      symptoms.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Adult Patients
      
Keywords: Bariatric Surgery; Sleep Apnea; Gastroesophageal Reflux Disease; GERD