Background: Salt chamber treatment reduced bronchial hyperresponsiveness as an add-on therapy in asthmatics on inhaled steroids (Hedman, J. et al, Allergy 2006; 61: 605-610) but in the further study it did not affect the inflammatory markers in induced sputum (ERS Congress 2007, abstract). In asthma patients elevated FeNO has been shown to be a marker of eosinophilic inflammation. We performed a randomised, double-blind, placebo-controlled cross-over trial to assess the effects of salt chamber treatment on FeNO in patients with symptoms suggesting asthma.
Methods: After a one-week baseline 21 symptomatic patients with FeNO >20 ppb but normal spirometry and normal variation in PEF-monitoring were randomized to receive either salt chamber treatment [7.6 mg/m3 (n=11)] or placebo [0.2 mg/m3 (n=10)] in a cross-over manner. The wash-out period was one week between the 2-week treatment periods (10 daily sessions of 40 min each). FeNO, lung volumes (FEV1, FVC), PEF-values, symptoms and use of rescue beta-2-agonists were recorded. Sixteen patients completed the study and 5 stopped due to respiratory infection.
Results: Mean FeNO values before and after the active treatment period were 37.4 ppb and 39.8 ppb, respectively. Corresponding values for the placebo period were 45.6 ppb and 34.3 ppb. The differences were not significant. Changes in PEF-values, symptoms and the use of rescue beta-2-agonists did not differ between the treatment groups.
Conclusions: Salt chamber treatment did not reduce FeNO in patients with symptoms suggesting asthma.