Comparison of Esophageal Manometry and CT Scan Measurements

Sponsor

Massachusetts General Hospital (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT04213911

Collaborator

(none)

Enrollment

Location

Anticipated Duration (Months)

0.4

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The goal of this study is to determine the relationship between esophageal pressure (Pes) and superimposed pressure (SP) in subjects with morbid obesity.

Condition or Disease	Intervention/Treatment	Phase
Morbid Obesity Respiratory Failure	Radiation: low-dose chest CT scan Device: insertion of esophageal balloon

Detailed Description

In the clinical setting, Pes is a surrogate for pleural pressure, while SP is measured by means of chest CT scan images. The SP highly approximates the vertical pleural pressure gradient both in normal lungs and injured lungs in lean subjects. It is known that in the healthy obese patient the Pes is higher than that in normal lean patients, but there is no information about the relationship between high Pes with the SP in subjects with morbid obesity.

The investigators hypothesized that factors other than superimposed pressure determine the high Pes in subjects with morbid obesity. Hence, Pes should be high despite the low SP found in healthy obese individuals.

The investigators will test this hypothesis in a prospective observational cohort study.

In 12 subjects (6 with body mass index > 40kg/m2, and 6 with body mass index < 30kg/m2 ) with scheduled chest CT scan for clinical purposes:

The Pes will be measured during spontaneous breathing (baseline values at end-expiration and variations during tidal breathing). To achieve this purpose, an esophageal balloon (AVEATM Ventilator Esophageal Pressure Monitoring Tube Set, 8 FR, CareFusion, Yorba Linda, CA, USA) will be inserted after administration of local anesthesia (lidocaine spray 2%).
The SP will be determined by lung computed tomography imaging and the pleural pressure will be calculated in non-dependent lung regions as the difference between Pes and SP. For this purpose, an additional low-dose CT scan at the end-expiration will be taken after the scheduled CT scan.

During the research procedure, the Pes during the whole respiratory cycle, the CT image at the end-expiration, demographics, past and current medical history will be recorded.

There will be no follow-up phase in this study.

Study Design

Study Type:

Observational

Anticipated Enrollment :

12 participants

Observational Model:

Cohort

Time Perspective:

Prospective

Official Title:

Determination of Pleural Pressure in Subjects With Morbid Obesity

Anticipated Study Start Date :

Mar 1, 2021

Anticipated Primary Completion Date :

Dec 31, 2022

Anticipated Study Completion Date :

Jun 30, 2023

Arms and Interventions

Arm	Intervention/Treatment
Morbid obese BMI>40 kg/m2	Radiation: low-dose chest CT scan The low-dose chest CT scan is now commonly used as a quick, painless, and non-invasive approach to screen for lung cancer. The radiation exposure from one low-dose CT scan of the chest (1.5 mSv) is comparable to 6 months of natural background radiation for a person living in the US. Device: insertion of esophageal balloon The esophageal catheter is a flexible thin plastic tube with an air-filled balloon at the distal end. The tube will be placed through the nasopharynx after local anesthesia.
Non-obese BMI<30 kg/m2	Radiation: low-dose chest CT scan The low-dose chest CT scan is now commonly used as a quick, painless, and non-invasive approach to screen for lung cancer. The radiation exposure from one low-dose CT scan of the chest (1.5 mSv) is comparable to 6 months of natural background radiation for a person living in the US. Device: insertion of esophageal balloon The esophageal catheter is a flexible thin plastic tube with an air-filled balloon at the distal end. The tube will be placed through the nasopharynx after local anesthesia.

Arm

Intervention/Treatment

Morbid obese

BMI>40 kg/m2

Radiation: low-dose chest CT scan

The low-dose chest CT scan is now commonly used as a quick, painless, and non-invasive approach to screen for lung cancer. The radiation exposure from one low-dose CT scan of the chest (1.5 mSv) is comparable to 6 months of natural background radiation for a person living in the US.

Device: insertion of esophageal balloon

The esophageal catheter is a flexible thin plastic tube with an air-filled balloon at the distal end. The tube will be placed through the nasopharynx after local anesthesia.

Non-obese

BMI<30 kg/m2

Radiation: low-dose chest CT scan

Device: insertion of esophageal balloon

The esophageal catheter is a flexible thin plastic tube with an air-filled balloon at the distal end. The tube will be placed through the nasopharynx after local anesthesia.

Outcome Measures

Primary Outcome Measures

Esophageal pressure measurement at a given superimposed pressure [through study completion, an average of 1 year]
The esophageal pressure will be determined via esophageal balloon at the end of exhalation. The superimposed pressure will be calculated by chest CT scan image at the end of exhalation.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 99 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Patients who are scheduled to take a chest CT scan for the clinical purpose at MGH Radiology Department
6 adult subjects with BMI more than 40kg/m2
6 adult subjects with BMI less than 30kg/m2
More than 18 years old

Exclusion Criteria:

Presence of pneumothorax
History of spontaneous pneumothorax
Severe coagulopathy (INR ≥ 4)
Severe thrombocytopenia (Platelets count ≤ 5,000/mm3)
Usage of any devices with electric current generation such as pacemakers or internal cardiac defibrillator
Recent esophageal trauma or surgery
Other esophageal diseases, such as esophageal cancer, leak, varices, and hernia
Presence of hypoxemia, short of breath and dysphagia.
Presence or suspicion of pneumonia or lung fibrosis.