Assessment of Cough Reflex in Lung Transplant Recipients

The purpose of this study is to evaluate the presence of cough reflex in the transplanted lung of patients who have had either a single or double lung transplant or heart-lung transplant at University of Texas Medical Branch. At the 1 year post transplant bronchoscopy, the presence of the cough reflex will be assessed by placing 3 to 5 ml of 5% dextrose and placement of the bronchial biopsy forceps on the airway mucosa. Three to four separate areas of the transplanted airways will be assessed. The cough reflex will be assessed by recording the surface electrical activity by placing external electrodes to monitor the movement of abdominal muscles during a cough. The data will be recorded and compared with recordings from coughs recorded using the surface electrical activity of a cough generated by non-transplant patients.

Study Overview

• Status: Completed
• Conditions: Complication of Transplanted Lung

Detailed Description

Bronchoscopy Stable, lung transplant recipients undergoing surveillance bronchoscopy will be enrolled. We will exclude subjects with new or persistent cough, hypoxemia, new radiographic infiltrates, or hemodynamic instability.

Before bronchoscopy, patients will receive diazepam while codeine and atropine will be withheld. Upper airway anesthesia was performed using cotton swabs soaked with 4 % lidocaine applied on the oropharyngeal mucosa and gradually placed posteriorly with the aid of curved foreceps to anesthetize the supraglottic region. A trained individual will perform topical upper airway anesthesia over 15 minutes and adequate anesthesia will be determined once subjects fail to cough during foreceps application to the supraglottic region. Conscious sedation will be administered using intravenous midazolam while vital signs are monitored. Once adequate sedation is achieved, the bronchoscope will be introduced through the mouth beyond the vocal chords to the main carina and slowly advanced to the airway anastomosis. Coughing that occurs with advancement of the bronchoscope from the chords to the anastomosis will be addressed by maintaining the bronchoscope in an immobile neutral position for 60-180 seconds until coughing stops and the cough provocation will be performed.

Cough provocation Airway irritants will be applied in the following sequence: 1) one cm distal to anastomosis, 2) one cm proximal to anastomosis and 3) at the main carina. Chemical irritation will consist of 3 mL aliquots of 5 % dextrose water (D5W) instilled through the bronchoscope channel on the bronchial mucosa (21). Aliquots of D5W will be administered at each site on three separate occasions with a 60 second interval between administrations. Mechanical irritation will involve placement of the biopsy foreceps on the bronchial mucosa at each site. The sequence of airway irritation sites will always begin with the distal anastomosis followed by the proximal anastomosis and main carina.

Airway lidocaine administration Patients demonstrating a cough reflex at the distal anastomotic site will be recorded. After measurements are obtained at all airway sites, the bronchoscope will be reintroduced to the distal anastomosis and 3 mL of 4 % lidocaine instilled on the bronchial mucosa. Sixty seconds later, mechanical and chemical irritation of the proximal and distal anastomosis will be performed as previously outlined.

Cough assessment Cough frequency will be determined by counting audible coughs and abdominal muscle contractions measured with a surface electromyograph (EMG) recorder. Surface electrodes placed on the skin, 2 cm below each costal margin along the midclavicular line will be connected to an EMG recorder (Biopac Systems Inc, Santa Barbara, CA) linked to a dedicated computer. Continuous EMG recordings will be obtained 15 seconds before administration of the airway irritant to ensure absence of cough before airway irritant administration (Figure 1). Twenty seconds or more of recording will be obtained after airway irritant application. Cough will be defined as abdominal muscle contraction and audible expiratory sound.

• Study Type: Observational
• Enrollment (Actual): 15

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

Single or double lung or heart-lung transplant recipients

Description

Inclusion Criteria:

• Lung transplant recipient
• Hemodynamically stable
• Capable of undergoing bronchoscopy

Exclusion Criteria:

• Pneumonia
• Hypoxemia (PaO2 < 70)
• Hemodynamic instability
• Coagulopathy
• Thrombocytopenia

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Stable lung transplant recipients; All enrolled subjects receive the same procedures; bronchoscopy with administration of mechanical and chemical irritants to the airway mucosa

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Coughs	The number of coughs elicited by placement of biopsy forceps or instillation of dextrose solution on the airway mucosa. The presence of the cough reflex will be assessed with administration of mechanical (biopsy foreceps) and chemical (D5W) at the level of the main carina, proximal to airway anastomosis (native airway) and distal to the airway anastomosis (allograft airway).	15-20 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
to Assess the Presence and Strength of the Cough Reflex in the Lower Airway for up to One Year	Presence of cough as elicited by placement of biopsy forceps or instillation of dextrose solution on the airway mucosa. The presence of the cough reflex will be assessed with administration of mechanical (biopsy foreceps) and chemical (dextrose solution) at the level of the main carina, native lung airway and proximal and distal to the airway anastomosis. Lung transplant recipients underwent airway evaluations using the above protocel at 1.5 and 12 months after lung transplantation. after undergoing transplantation	15-20 minutes

Collaborators and Investigators

• Sponsor: The University of Texas Medical Branch, Galveston

Publications and helpful links

General Publications

• Duarte AG, Terminella L, Smith JT, Myers AC, Campbell G, Lick S. Restoration of cough reflex in lung transplant recipients. Chest. 2008 Aug;134(2):310-316. doi: 10.1378/chest.07-2934. Epub 2008 Mar 13.

Study record dates

Study Major Dates

• Study Start: April 1, 2000
• Primary Completion (Actual): October 1, 2006
• Study Completion (Actual): October 1, 2007

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): November 2, 2018
• Last Update Submitted That Met QC Criteria: February 20, 2018
• Last Verified: February 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: 00-132

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO