Hypertonic Saline

Question

Hello,
My daughter is currently very congested, the CF doctor told her that she is not infected but unable to clear her airway due to a very thick mucus. She feels trouble breathing, she coughs a lot and even more during the night or feels an extreme fatigue.
She has been performing RhDnase nebulization (Pulmozyme) for several years and apparently it is not efficient any more. I've read that hypertonic saline may be used to replace. What do you think about it and how is it administered (I think it's also aerosolized but I'm not sure) ?
Thank you in advance for your reply.

Answer

Treatments designed to make the mucus more fluid are recommended by the Good Practice Guidelines in order to improve the airway clearance and break the vicious circle of inflammation-infection-congestion-broncho-pulmonary lesions. These recommendations are based on numerous clinical studies. For practical reasons (the possibility to assess the effectiveness of treatment by performing pulmonary function tests), these studies were mainly run in patients 6 years or more. The most recent recommendations, published in 2007, are those of the US Cystic Fibrosis Foundation - U.S. CFF - (1).
Among the recommended treatments are actually daily inhaled RhDNase (1/day) and hypertonic saline (BID or TID).
Regarding RhDNase, this recommendation is strong (Grade A) in patients 6 years or over who are lung disease qualified "medium" (FEV between 40 and 69% of the expected value for age and sex) or "severe" (FEV less than 40%): a substantial profit is indeed demonstrated with a good level of evidence. The treatment recommendation is a bit less strong (Grade B) for patients 6 years or older, asymptomatic (having an FEV1 greater than or equal to 90%) or moderate lung disease (FEV between 70 and 89%). The level of benefit evidence, although significant, is lower. The strength of recommendation does not mean that the treatment effectiveness is lower but the level of evidence of its effectiveness is more difficult to establish in a situation of preventive treatment.
Regarding hypertonic saline (6 or 7% NaCl), the strength of the recommendation in patients 6 years and older is a bit lower (grade B), the standard of proof with respect the lung function improvement and the decrease of exacerbations being rated as average. Again, this is not the effectiveness of treatment, but proof of its effectiveness that is rated as "average".
For children under 6 years there is not currently recommendations based on sufficient evidence. This is related, on one hand, to the difficulties encountered for including young children in clinical trials, on the other hand, to the lack of evaluation technique sensitive enough to measure a significant improvement in children with asymptomatic or mild lung disease.
We currently have no evidence to confirm the advantage of treatment over another (rhDNase versus hypertonic saline). Moreover, even if the criteria for recommendation are met, the effects of treatment vary from patient to patient. The benefit for a given patient can be evaluated after at least 6 weeks of treatment properly administered, by weighing its benefits - gain in FEV1 - and disadvantages - side effects, impaired quality of life and cost - (2 ).
I urge you to discuss with your CF Center Physician about the opportunity to test the effect on FEV1 of a temporary cessation of inhaled rhDNase before deciding what action to take: either re-treatment if the FEV1 decreases and goes up after rechallenge or stop otherwise. In the latter case, a trial of treatment of inhaled hypertonic saline may be prescribed and long term maintained if it is proved effective and well tolerated.
Sincerely.
Gilles Rault, MD, Northwestern France CF Network

20.06.2011