Nasal inspiratory pressure as an indirect measurement of respiratory muscle strength measured during SNIP and Psn methods in healthy subjects and subjects with motor neurone disease

Conclusion Psn may be used to complement SNIP in the evaluation of respiratory muscle testing of patients, particularly in those patients who have significant bulbar weakness throughout disease progression. Thus, Psn may be more informative in advanced disease. However, the lack of published reference values to date for Psn may limit its utility as a diagnostic or serial measurement tool in the short term.