EFFECT OF INCREASING DOSES OF HYPERTONIC SALINE ON MUCOCILIARY CLEARANCE IN PATIENTS WITH CYSTIC-FIBROSIS

Background - Patients with cystic fibrosis are known to have decreased mucociliary clearance. It has previously been shown that inhalation o f a 7.0% solution of hypertonic saline significantly improved mucocili ary clearance in a group of adult patients with cystic fibrosis. The a im of this study was to measure the response to increasing concentrati ons of inhaled hypertonic saline. Methods - Ten patients (seven men) o f mean (SE) age 22 (4) years and mean forced expiratory volume in one second (FEV1) 52.0 (6.7)% predicted completed the study. Mucociliary c learance was measured using a radioaerosol technique for 90 minutes af ter the interventions which comprised 0.9% NaCl + voluntary cough (con trol), 3.0% NaCl, 7.0% NaCl, and 12% NaCl. Results - There was a signi ficant increase in the amount of activity cleared from the right lung with all concentrations of hypertonic saline (HS) compared with contro l. The amount cleared at 90 minutes on the control day was 12.7% (95% confidence interval (CI) 9.8 to 17.2) compared with 19.7% (95% CI 13.6 to 29.5) for 3% HS, 23.8% (95% CI 15.9 to 36.7) for 7% HS and 26.0% ( 95% CI 19.8 to 35.9) for 12% HS. The improvement in mucociliary cleara nce was not solely due to coughing as the number of coughs recorded on the control day exceeded that recorded on any other day. The hyperton ic saline did not induce a clinically significant change in FEV1. Conc lusions - Within the range of concentrations examined in this study, t he effect of hypertonic saline appears to be dose dependent. Inhalatio n of hypertonic saline remains a potentially useful treatment for pati ents with cystic fibrosis.