Inhaled Bicarbonate Therapy in Cystic Fibrosis

There is evidence that people with CF may have differences in the liquid that lines the
surface of their lungs from people without CF. There are two things that are known to be
different. One is called bicarbonate secretion, which is the movement of a salt called
bicarbonate that is normally present in the blood and lung fluid in all people. The abnormal
movement of bicarbonate appears to cause a second abnormality - the liquid in the breathing
tubes has more acid than the liquid in patients without CF. These differences may affect the
stickiness and thickness of the mucus and limit how well the hairs that line the breathing
tubes (cilia) move mucus out of the lungs.

Recent studies in a group of patients with chronic cough looked at the effects of giving an
inhaled bicarbonate solution (sodium bicarbonate instead of sodium chloride) on the study
subjects' ability to cough up mucus. Compared to the group given inhaled saline, the
patients given inhaled bicarbonate were able to cough up approximately three times as much
mucus. No clinical studies have looked at whether inhaled bicarbonate improves the ability
of the lung in a person with CF to move mucus out of the lung or how this treatment affects
lung function in patients with CF.

Inclusion Criteria:

- age 12 or older

- Forced expiratory volume in one second (FEV1) >40% predicted

- Ability to expectorate sputum

Exclusion Criteria:

- pregnancy

- pulmonary exacerbation or initiation of inhaled or oral antibiotics, steroids, or
aerosol treatments within the last four weeks

- oxygen saturation <92%, or requirement for supplemental oxygen