Importance of nasal clipping in screening investigations of flow volume curve

Comparative analysis of some basic lung indices obtained from a screening investigation of the flow volume curve by using two techniques, with a nose clip and without a nose clip, was made on a cohort of 86 workers in a factory shop for the production of bearings. We found no statistically significant differences between the indices obtained by the two techniques. Our study showed that the FVC and FEV1 obtained in workers without using nose clips were equal to or better than those obtained using nose clips in 60% of the workers. The reproducibility of the two methods was similar. The analysis of the data has shown that the flow volume curve investigation gives better results when performed without a nose clip, especially in industrial conditions.