Acute and durable effect of inhaled hypertonic saline on mucociliary clearance in adult asthma

Background Impaired mucus clearance and airway mucus plugging have been shown to occur in moderate to severe asthma, especially during acute exacerbations. In cystic fibrosis (CF), where airway mucus is dehydrated, it has been shown that inhaled hypertonic saline (HS) produces both acute and sustained enhancement of mucociliary clearance (MCC). The current study was designed to assess the acute and sustained effect of inhaled 7%HS on MCC in adult asthma. Methods Well-controlled, moderate-severe female asthmatics (n=8) were screened with a single test dose of albuterol (4 puffs by metered dose inhaler) followed by HS (7% NaCl, 4 mL nebulised by Pari LC Star). Spirometry was measured at pre-treatment and 5- and 30-min post-treatment for safety. MCC was measured by gamma scintigraphy on three separate visits: at baseline, during inhalation of, and 4-h after a single dose of HS. Results MCC was acutely enhanced during HS treatment, mean clearance over 60 min of dynamic imaging Ave60Clr=8.9±7.9% (baseline) versus 23.4±7.6% (acute HS) (p Conclusion While MCC was rapidly enhanced during 7%HS treatment there was no effect on MCC at 4-h post treatment. While these findings may not support aerosolised HS use for maintenance therapy they do suggest a benefit for treating acute exacerbations in moderate-severe asthmatics.