Exhaled and nasal nitric oxide in laryngectomized patients

Abstract

<p>Abstract</p> <p>Background</p> <p>Nitric oxide (NO) shows differing concentrations in lower and upper airways. Patients after total laryngectomy are the only individuals, in whom a complete separation of upper and lower airways is guaranteed. Thus the objective of our study was to assess exhaled and nasal NO in these patients.</p> <p>Methods</p> <p>Exhaled bronchial NO (FE_NO) and nasal nitric oxide (nNO) were measured in patients after total laryngectomy (n = 14) and healthy controls (n = 24). To assess lung function we additionally performed spirometry. Co-factors possibly influencing NO, such as smoking, infections, and atopy were excluded.</p> <p>Results</p> <p>There was a markedly (p < 0.001) lower FE_NOin patients after total laryngectomy (median (range): 4 (1-22) ppb) compared to healthy controls 21 (9-41) ppb). In contrast, nNO was comparable between groups (1368 <it>versus </it>1380 in controls) but showed higher variability in subjects after laryngectomy.</p> <p>Conclusions</p> <p>Our data suggest that either bronchial NO production in patients who underwent laryngectomy is very low, possibly due to alterations of the mucosa or oxidant production/inflammation, or that substantial contributions to FE_NOarise from the larynx, pharynx and mouth, raising FE_NOdespite velum closure. The data fit to those indicating a substantial contribution to FE_NOby the mouth in healthy subjects. The broader range of nNO values found in subjects after laryngectomy may indicate chronic alteration or oligo-symptomatic inflammation of nasal mucosa, as frequently found after total laryngectomy.</p