A Randomised trial of the effect of timing of nebulised hypertonic saline in relation to airway clearance physiotherapy, in people with Cystic Fibrosis lung disease.

Following consent, subjects will be randomised to three timing regimes of 6% hypertonic saline (HS) inhalation over three days. Each day subjects will perform baseline spirometry, inhalation of bronchodilator, and inhalation of HS: either immediatly pre (not greater than 30 minutes pre), during (blocks of 10-15 breaths intersperced with airway clearance physiotherapy) or post (not greater than 30 minutes post) airway clearance physiotherapy in random order. The three inhalation regimes will be carried out over three consecutive days (no washout) at the end of a hospital admission when clinical signs have stabilised. The timing regime for that day will be performed for each airway clearance physiotherapy session. Participants will perform their usual daily number of airway clearance sessions (1-3), the same number will be performed on each of the study days. Each HS inhalation will be 4mLs (usually 15-20 minutes to deliver). Each airway clearance physiotherapy session will be 20-40 minutes with the duration for that participant similar for the three days. A post treatment spirometry will be performed two hours post baseline spirometry each day and a VAS completed regarding ease of expectoration, tolerability and overall satisfaction for this order of inhalation and aiway clearance. The spirometry readings will be recorded with the afternoon physiotherapy treatment. Thus the pre and post spirometry readings are two hours apart at a similar time of the day on each of the study days.