The goal of this clinical research study is to compare the effects of sodium bicarbonate to normal saline when used for clearing mucus blockage in patients with airway stents.

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.

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.

Follow-Up:

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 investigational.

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 saline.
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.