Correlation of Exhaled Nasal Nitric Oxide With Sinus Computed Tomography and Sinonasal Outcome Test Scores: A Cross-sectional Pilot Study

Background Computed tomography (CT) of the paranasal sinuses is the diagnostic reference standard for chronic rhinosinusitis and related inflammatory sinus pathology. Nasal nitric oxide (nNO) levels have been investigated as a diagnostic tool in sinus disease because it decreases with sinus obstruction. Objective The primary aim of the study was to determine the correlation of passive (baseline) and dynamic (humming) nNO to CT findings of sinus inflammation and to sinonasal symptoms measured by the modified Sinonasal Outcome Test (26 items) (SNOT-26). Methods From June 2015 through January 2016, subjects had baseline and humming nNO levels measured with a chemiluminescence NO analyzer, and each subject underwent CT imaging and completed the SNOT-26 survey. CT images were scored using the Lund–Mackay (LM) system (LM scores >3 indicated sinus inflammation). Correlation was measured by linear and ordinal regression analysis that compared SNOT-26 scores, LM scores, and nNO measurements. Results Fourteen subjects were recruited. LM scores had a positive pairwise correlation with total SNOT-26 scores (R2 = .1457; correlation = .3817) and nasal-specific SNOT-26 scores (R2 = .4036; correlation = .6353). Baseline nasal nNO scores had a negative pairwise correlation with LM scores (R2 = .1580; correlation = −.3582), total SNOT-26 scores (R2 = .1515; correlation = −.3893), and nasal-specific SNOT-26 scores (R2 = .0805; correlation = −.4343). Although baseline nNO levels correlated with LM and SNOT-26 scores, humming nNO levels did not show a similar correlation. Conclusion Baseline passive nNO may be a useful and inexpensive point-of-care screening test for sinonasal opacification.