Low nasal nitric oxide levels in patients with CRS symptoms are associated with a subsequent surgical treatment

The symptoms of chronic rhinosinusitis (CRS) are common. Diagnosis with computed tomography (CT) and endoscopy is not possible in all patients. Nasal nitric oxide (nNO) detects the obstruction of paranasal sinus ostia, but its clinical relevance is unknown. We assessed whether nNO, Sinonasal Outcome Test 22 (SNOT-22) and Zinreich modified Lund–Mackay (ZL-M) CT-scores are associated with subsequent surgery among CRS or recurrent acute rhinosinusitis (RARS) patients. Sixty-six CRS (with/without nasal polyps) or RARS patients were included in this prospective study. Appropriate medical therapy was used for at least 2 months. Patients were assessed during three consecutive visits: on current prescriptions, after a medication pause, and after intranasal fluticasone propionate. The clinician was unaware of the nNO results during subsequent treatment decisions. The positive predictive value (PPV) of nNO for the decision to proceed with surgical intervention “after fluticasone” was 76%, and the negative predictive value (NPV) was 80%. These results were not statistically significantly different from those of the ZL-M (PPV 76%; NPV 82%). Low nNO in patients with CRS symptoms was associated with a later decision for surgery. The applicability of nNO to guide ENT referrals from primary care should be further evaluated.