This is a repeat of something I've posted before, but it's appropriate to post it again based on your question, as I'm sure others are wondering the same thing.
I often do CPT without a bronchodilator unless my asthma is acting up or I'm fighting infection. I also am asked why I do Xopenex. Usually RTs in the hospital ask me that because they are more familiar with albuterol. I choose Xopenex over albuterol because of the extreme jittery/anxious feelings I exhibit with albuterol that don't occur with Xopenex. For me, that's a quality of life decision, not necessarily a scientific one.
I do use bronchodilators both as a "rescue med" and as part of my preventive maintenance even if I don't do them at the same time as CPT. Bronchodilators are most effective when they are done first in the lineup of "usuals." Below is the proper order of med-neb treatments, as reported by another CF patient's clinic's recommendation:
1. Bronchodilator (albuterol or xopenex)
2. Mucolytics (pulmozyme THEN hypertonic saline)
3. Inhaled antibiotic (TOBI or colistin)
4. Long acting bronchodilator (serevent or foradil)
5. Inhaled steroid (flovent, advair, or pulmicort)
Here's why the order of operations is so important when managing CF.
The bronchodilator helps open up the airways. The more open the airways, the better the chances of inhaling the other medications deeply enough into the lungs where they can be most effective. Mucolytics are "mucus cutting" medications. They help break up the secretions so that they can be coughed up more easily. In CF patients, the mucus and the lungs are typically dry, which is why hypertonic saline is so useful. Hypertonic saline works by adding moisture to the lining of the lungs, resulting in a slippery surface conducive coughing out sputum. Following sputum clearance of the airways, the lungs are further able to take in the nebulized mist of the antibiotics. At this point there is a greater likelihood of the antibiotics taking hold in both small and large airways. The treatment concludes with inhaled steroids which help keep the airways open for an extended period of time (i.e. 8-12 hours when it is time for another treatment.)
The length of time to complete all these steps varies somewhat depending on the type of nebulizer/compressor system being used. For me this process takes approximately half an hour when I am not in a TOBI month and not producing much sputum. When I am not feeling well, am more congested or taking TOBI, it can take me as long as 1-1/2 hours to complete the process.