The principle of vibrating inhalation is implemented in novel nebulizers, with which sinonasal inhalation is performed by aerolized medication into one nostril, while the contralateral nostril is occluded and the soft palate elevated as recommended for nasal lavage. The medication is administered into both nostrils for 4-6 min each side during phases of arrest of breathing. Choice of antibiotics depends on resistance testing from microbiological results. Patients will be divided into different groups, on the basis of the inhaled antibiotic regimen being chosen: colistin vs. tobramycin. An alternate therapy with hypertonic saline may be applied to improve sinus clearance. All regimens will be administered with the same machine, i.e. PARI Sinus ™ nebulizer, which, unlike conventional aerosols, allows the deposition of drugs directly into the paranasal sinuses.