High-resolution Computed Tomography (HRCT) Evaluation of Airway Distensibility in Lung Transplant Recipients

High Resolution Computed Tomographic Evaluation of Airway Distensibility in Lung Transplant Recipients: A Pilot Study

Lung and heart-lung recipients at the University of Texas Medical Branch who have participated in the "Assessment of Cough Reflex in Lung Transplant Recipients" study who meet the specific study inclusion/exclusion criteria will have one study visit where they will undergo lung volume measurements, followed by high resolution CT scan of the lungs within 2 hours. After the initial CT scan, patients will be given a standard dose of Atrovent, followed thirty minutes later by repeat lung volume measurements and CT scan.

Study Overview

• Status: Completed
• Conditions: Unspecified Complication of Lung Transplant

Detailed Description

Chest CT imaging will be obtained in the radiology department at UTMB. After the initial screening visit, subjects will visit the pulmonary function laboratory where they will undergo spirometry and measurement of lung volumes by whole body plethysmography. Within two hours of pulmonary function testing, subjects will undergo an initial HRCT scan. After the initial HRCT, subjects will inhale a standard dose of ipratropium bromide (0.5 mg) using a hand held nebulizer. Thirty minutes after ipratropium bromide administration, spirometry will be measured followed by a second HRCT scan.

Spirometry measurements will be performed in triplicate with the subjects in a seated position using a portable Koko spirometer (PDS, Louisville, CO). After the spirometry measurements, lung volumes will be measured in a body plethysmograph (MedGraphics, St. Paul, MN) with the subjects in a seated position with a nose clip. Subjects will be instructed to pant against the closed shutter at a frequency of 1-3 Hz. Lung volume measurements will be obtained prior to inital chest CT. Subjects will undergo high resolution computed tomography (HRCT) scanning within 30 minutes of initial lung volume measurements.

After the initial HRCT of the chest, subjects will inhale a dose of nebulized ipratropium bromide (0.5 mg) by standard nebulizer after which spirometry and lung volume measurements will be repeated in the pulmonary function laboratory. Spirometry and lung volume measurements will be performed in the same manner. Lung volume measurements will be obtained to account for changes in lung volumes after bronchodilator administration. Changes in lung volumes will be used to account for any changes noted on HRCT scans.

HRCT scanning will begin 6 cm above the top of the dome of the diaphragm, at TLC and moved caudally. Images will be reconstructed with the use of a high-spatial frequency (resolution) algorithm that enhanced edge detection, at a window level of -450 Hounsfield units and a window width of 1,350 Hounsfield units. We will consider the airway diameters after maximum bronchodilation with ipratropium to be a function principally of the structural characteristics of airways. The TLC measurements after ipratropium will be the best reflection of intrinsic structure. CT airway measurement analysis will be performed by VIDA Diagnostics. We have entered into a collaboration with VIDA Diagnostics that will allow accurate and reliable CT airway measurements. Subject's CT images obtained at UTMB will be deidentified and electronically transmitted to a research collaborator at VIDA Diagnostics located in Coralville, IA. The CT images will have a code assigned, known only to the PI. Using a proprietary software platform, airway measurements will be performed and the data electronically transmitted to the PI at UTMB.

• Study Type: Observational
• Enrollment (Actual): 10

Contacts and Locations

Study Locations

• United States
  • Texas
    • Galveston, Texas, United States, 77555
      • University of Texas Medical Branch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

All patients who participated in the "Assessment of Cough Reflex in Lung Transplant Recipients" study who meet the specific inclusion/exclusion criteria for this study

Description

Inclusion Criteria:

• lung transplant recipients >18 years of age
• at least 12 months or greater from time of transplantation

Exclusion Criteria:

• hemodynamic instability
• hypoxemia
• pneumonia
• moderate or large pleural effusion
• clinical evidence of acute rejection

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Lung transplant recipients; Lung transplant recpients enrolled as study subjects will undergo pulmonary function tests (spirometry and lung volume measurements) and initial HRCT of chest. These subjects will receive nebulized ipratropium followed by pulmonary function tests (spirometry and lung volume measurements) and repeat HRCT.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Spirometry changes	Assessment of changes in spirometry following inhalation of nebulized ipratropium	Two hours (before and after inhalation of ipratropium)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung volumes	Assessment of changes in total lung capacity, functional reserve capacity and inspiratory capacity following inhalation of nebulized ipratropium	Two hours (before and after inhalation of ipratropium)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiographic changes in airway caliber	Assessment of changes in airway caliber as determined by high resolution chest CT images following inhalation of nebulized ipratropium	Two hours (before and after inhalation of ipratropium)

Collaborators and Investigators

• Sponsor: The University of Texas Medical Branch, Galveston

Study record dates

Study Major Dates

• Study Start: August 1, 2007
• Primary Completion (ACTUAL): January 7, 2018
• Study Completion (ACTUAL): January 7, 2018

Study Registration Dates

• First Submitted: December 20, 2007
• First Submitted That Met QC Criteria: December 20, 2007
• First Posted (ESTIMATE): January 2, 2008

Study Record Updates

• Last Update Posted (ACTUAL): February 22, 2018
• Last Update Submitted That Met QC Criteria: February 19, 2018
• Last Verified: February 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: 07-247