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Clearance Of Mucus In Stents (COMIS)

18 Years
Open (Enrolling)
Lung Neoplasms, Respiratory Failure, Pneumonia, Acute Coronary Syndromes, Unstable Angina, Myocardial Infarction, Cardiac Arrhythmia, Thromboembolic Disease

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Trial Information

Clearance Of Mucus In Stents (COMIS)

Study Agents:

Sodium bicarbonate is also called baking soda. In this study it will be mixed with water.

Normal saline is a salt water solution.

Study Groups:

If you agree to take part in this study, you will be randomly assigned (as in the flip of a
coin) to 1 of 2 study groups. The study doctor will use either sodium bicarbonate or normal
saline during your bronchoscopy to clear mucus from your stent:

- If you are in Group 1, the study doctor will use sodium bicarbonate. The amount of
sodium bicarbonate in the solution will be the same for all patients in Group 1.

- If you are in Group 2, the study doctor will use normal saline.

You will have an equal chance of being assigned to either group. Neither you nor the study
staff can choose the group you will be in, and neither you nor your doctor will know if you
are receiving sodium bicarbonate or normal saline. However, if needed for your safety, the
study staff will be able to find out what you are receiving.

Study Procedure:

If you have more than 1 stent, only 1 of your stents will be checked for clearance of mucus
in this study. However, all stents will be cleared of mucus if needed.

As part of your standard of care, you will have photographs and videos taken before and
after your bronchoscopy. You will sign a separate consent form for your bronchoscopy. Your
complete medical history will also be recorded.

For the bronchoscopy, you will be given drugs to help you relax, and then a local anesthetic
will be sprayed into your nose and throat to numb those areas. A slim, flexible tube with a
light will be placed through your nose or mouth and into your airway tubes.

If you are in Group 1, a small amount of sodium bicarbonate will be sprayed into your
stent/airway tubes and then suctioned out through the bronchoscope.

If you are in Group 2, a small amount of normal saline will be sprayed into your
stent/airway tubes and then suctioned out through the bronchoscope.

Next, 3 study doctors will check how well the mucus in your stent was cleared. If the study
doctors think not enough mucus has been cleared from your stent, you will "crossover" into
the other study group and receive the other agent to clear your mucus.

Length of Study:

Your participation on the study will be over after you have completed the follow-up visits.


At about 7 days, and then again 30 days after your bronchoscopy, you will come to the clinic
for a follow-up visit. The following procedures will be performed:

- You will have a physical exam, including measurement of your vital signs (blood
pressure, heart rate, temperature, and breathing rate).

- You will also be asked about any side effects you may be having.

This is an investigational study. Normal saline and sodium bicarbonate are agents used in
bronchoscopies performed in patients with airway stents as standard of care. The comparison
of sodium bicarbonate to normal saline to clear mucus from airway stents is considered

Up to 40 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Adult patients (>/= 18 years) with airway stents undergoing bronchoscopy.

2. Patients previously enrolled, but excluded as no stent lumen obstruction from mucus
retention identified at earlier enrollment (hence excluded at that enrollment) .

Exclusion Criteria:

1. Patients with history of allergy or adverse reactions to sodium bicarbonate or normal

2. Patients refusing to sign informed written consent for participation in research.

3. Patients with no stent lumen occlusion from mucus impaction as determined at the time
of the initial visual bronchoscopic assessment.

4. Previously enrolled patients who completed this protocol.

Type of Study:


Study Design:

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Diagnostic

Outcome Measure:

Percentage of obstruction resolution as Good or Excellent

Outcome Description:

Response/efficacy of sodium bicarbonate versus normal saline in airway stents graded using scale. Percentage of obstruction resolution (relative to initial stent lumen obstruction by mucus): Good response 51-75% clearance; and Excellent 76 - 100% clearance. The Mantel-Haenszel chi-square test stratified by degree of lumen obstruction at study enrollment used to compare response (good or excellent obstruction resolution) rates between treatment arms.

Outcome Time Frame:

Baseline to 7 days

Safety Issue:


Principal Investigator

Carlos A. Jimenez, MD

Investigator Role:

Principal Investigator

Investigator Affiliation:

UT MD Anderson Cancer Center


United States: Institutional Review Board

Study ID:




Start Date:

June 2011

Completion Date:

Related Keywords:

  • Lung Neoplasms
  • Respiratory Failure
  • Pneumonia
  • Acute Coronary Syndromes
  • Unstable Angina
  • Myocardial Infarction
  • Cardiac Arrhythmia
  • Thromboembolic Disease
  • Central airway obstruction
  • lumen obstruction
  • Sodium bicarbonate
  • Baking soda
  • Normal saline
  • Salt water
  • Airway stents
  • Bronchoscopy
  • mucus obstruction
  • Angina, Unstable
  • Arrhythmias, Cardiac
  • Neoplasms
  • Infarction
  • Lung Neoplasms
  • Myocardial Infarction
  • Pneumonia
  • Thromboembolism
  • Acute Coronary Syndrome
  • Respiratory Insufficiency



UT MD Anderson Cancer Center Houston, Texas  77030