Spirometric forced volume measurements in the assessment of nasal patency after septoplasty. A prospective clinical study.

Methods for assessing the nasal patency are needed in the evaluation of patients with symptoms of nasal stenosis. Apart from the commonly used rhinomanometric method spirometric forced volume measurements as well as nasal peak flow rate have gained interest especially in studies concerning allergic rhinitis and nasal hyperreactivity. We have measured the expiratory and inspiratory forced volume in 0.5 second through the mouth and nose in 12 patients before and after septoplasty and in ten controls. A nasal patency index (NPI) was calculated from the ratio between nasal and oral measurements. The expiratory and inspiratory NPI for the preoperative worst cavity and the expiratory NPI for the total nose showed significant improvement. These indices from the patients preoperative measurements also differed significantly from controls. We found the method easy to handle and sensitive enough to detect changes of the nasal patency after septoplasty.