Intranasal Deposition of Nebulized Saline: A Radionuclide Distribution Study

Abstract

Background Despite the popularity of various nasal sprays and nebulizers, there are limited data regarding the anatomic distribution of particles generated by these devices. This pilot study sought to characterize distribution patterns of nebulized and sprayed saline particles in normal subjects and postsurgical sinus patients. Methods Fifteen subjects were studied in three trials: metered-dose nasal spray bottle versus vortex-propelled nebulizer in normal subjects, passive-diffusion nebulizer versus vortex nebulizer in normal subjects, and passive nebulizer versus vortex nebulizer in postsurgical sinus patients. Radiolabeled saline was administered, and nose, lungs, and stomach were imaged. Images were scored by four blinded reviewers for degree of penetration at nine anatomic subsites. Results Compared with spray bottle, the vortex nebulizer showed more focal intranasal distribution with reduced nasopharyngeal, pharyngeal, and gastric penetration in normal subjects. Three of five subjects showed probable frontal sinus penetration by vortex nebulizer, but no other sinus penetration was noted. No patients showed sinus penetration with the spray bottle. In a separate trial against the passive nebulizer, the vortex nebulizer again showed a greater tendency for sinus penetration in normal subjects, with three of five showing some degree of sphenoid penetration and one of five showing slight maxillary penetration. In contrast, no sinus penetration was observed with the passive nebulizer. In the postsurgical patient cohort, minimal sinus penetration was noted with either the vortex nebulizer or the passive nebulizer. Despite surgically patent sinuses, only one of five subjects showed any type of sinus penetration. Conclusion The nebulizer and nasal spray devices tested in general showed limited penetration of the sinuses in both normal and postoperative patients. The device showing greatest promise for sinus penetration in normal patients was the vortex nebulizer, with an overall penetration rate in normal patients of 30% in the frontal, 30% in the sphenoid, and 10% in the maxillary. Understanding delivery patterns of topical therapies may be important in evaluating the efficacy of various topical treatment modalities.