[Improvement of objective diagnostic methods for acute rhinosinusitis]

To evaluate the diagnostic significance of nasal fractional exhaled nitric oxide (nFeNO) in patients with acute rhinosinusitis (ARS) and determine its relationship with clinical and instrumental parameters.

The study included 44 patients with moderate acute rhinosinusitis and 33 healthy volunteers. The nFeNO level was measured using a portable electrochemical gas analyzer (NOBreath). Endoscopic assessment was performed using the modified Lund-Kennedy scale (m-LK), radiological assessment using the Lund-Mackay scale (LM), and symptom severity assessment using the SNOT-22 questionnaire. Measurements were performed at baseline, on days 7-10, and on days 30-35 of treatment.

Baseline nFeNO levels in ARS patients were significantly lower than in the control group (p<0.05). In unilateral lesions, decreased nFeNO levels were observed both on the affected and contralateral sides. During treatment, nFeNO levels increased and reached values comparable to the control group by days 30-35 (p>0.05). A stable negative correlation of moderate to high strength was found between nFeNO levels and the severity of clinical and radiological changes assessed by the m-LK and LM scales. The correlation with SNOT-22 scores was weak.

NFeNO is a non-invasive biomarker of inflammation in ARS reflecting the severity of the pathological process and may be used for objective assessment of disease progression and treatment efficacy.