Please don't give up. Bronchiectasis is an uncommon disease, and it is not unusual to find doctors who know well how to treat COPD and asthma, but are not that familiar with the added burden of this.

It is also possible that, due to your Dad's other lung conditions, and perhaps his general health, that other antibiotic regimens are not an option.

Have you considered seeking care for him at a large multi-disciplinary facility that specializes in complex cases. Two that immediately come to mind are Mayo (seek appointments here: http://mayocl.in/1mtmR63 and National Jewish Health in Denver.

Does he have access to a large facility near home?
Sue