How do nasal sprays and irrigations compare in delivering topical agents to the human olfactory epithelium?
Background: Sinonasal diseases are often treated with topical agents administered through various application techniques, but few prior studies have examined their distribution to the olfactory mucosa. To date, the most popularly prescribed preparation of topical therapies is nasal spray; however, recent published studies have highlighted the therapeutic benefits of nasal irrigations.
Explore this issue:December 2013
Study design: Human cadaveric study using eight formaldehyde-preserved cadaveric heads with 15 available nasal sides; image pixel intensity was correlated with staining intensity.
Setting: Department of Otolaryngology–Head and Neck Surgery at Northwestern University, Evanston, Ill.
Synopsis: Each specimen underwent trials with methylene blue, first applied with the spray device (two sprays administered into each nare while the specimen was held in a forward-tilted position with sprays directed away from the septum) and then the irrigation squeeze bottle. Based on average reviewer ratings, irrigations showed greater distribution within all six anatomical subsites than sprays, but a more widespread distribution was particularly noted in the sphenoethmoid recess, superior turbinate and superior olfactory cleft. The spray group distribution was more comparable to the irrigation group within the anterior/middle subsites. No significant difference between sprays and irrigations existed at the nasal vestibule and middle turbinate, but irrigations had significantly higher average intensity ratios at all six individual subsites. Extensive sinonasal access achieved by irrigations meant that irrigations delivered a surface concentration 7.1 times higher than sprays. Limitations were generally related to using cadaveric specimens: the inability to reproduce mucociliary clearance and epithelial barriers characteristic of the physiologic state and lack of patient-related variables including patient comfort and proper usage.
Bottom line: Compared with sprays, irrigations provide a more effective method of delivering topical agents to the posterior and superior aspects of the nasal cavity.
Citation: Lam K, Tam BK, Lavin JM, Meen E, Conley DB. Comparison of nasal sprays and irrigations in the delivery of topical agents to the olfactory mucosa. Laryngoscope. 2013;123: 2950-2957.
—Reviewed by Amy Eckner