Nebulised hypertonic saline for cystic fibrosis

Abstract

Background: Lung disease in cystic fibrosis is characterised by impaired mucociliary clearance. Hypertonic saline has been shown to enhance mucociliary clearance in vitro and this may act to lessen the destructive inflammatory process in the airways.

Objectives: To investigate the effects of treatment with nebulised hypertonic saline on people with cystic fibrosis compared to placebo and or other treatments that enhance mucociliary clearance.

Search strategy: 'We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Most recent search of the Trials Register: September 2004.

Selection criteria: All controlled trials assessing the effect of hypertonic saline compared to placebo or other mucolytic therapy, for any duration or dose regimen in people with cystic fibrosis of any age or severity.

Data collection and analysis: Two authors independently reviewed all identified trials and all data collected. Trial quality was assessed along with allocation concealment.

Main results: Fourteen controlled trials were identified. Nine trials met the inclusion criteria involving 235 participants with an age range of 6 years to 46 years. Two short-term trials of immediate effect on mucociliary clearance demonstrated that hypertonic saline increased isotope clearance compared to control. Lung function, measured by improvement in forced expiratory volume at one second (FEV1 litre per minute), was observed in four trials. When 3% to 7% saline was used in a volume of 10 ml twice-a-day, in comparison to placebo, hypertonic saline led to a significant increase in FEV1, weighted mean difference 12.20 (95%CI 4.28 to 20.10). Two further trials compared a similar concentration and volume of hypertonic saline to recombinant deoxyribonuclease. Over a three-week period one trial showed a non-significant difference, mean difference 1.60 (95% CI -7.96 to 11.16). However, in a further trial, after 12 weeks treatment in participants with moderate to severe lung disease, recombinant deoxyribonuclease led to a greater increase in FEV1 than hypertonic saline (5 ml twice-daily), mean difference 8.00 (95%CI 2.00 to 14.00). No serious adverse events were noted.

Authors' conclusions: Nebulised hypertonic saline improves mucociliary clearance in short-term clinical trials and appears to increase lung function compared to control. In comparison to recombinant deoxyribonuclease it may be less effective at improving lung function after three months. Currently there is insufficient evidence to support the use of hypertonic saline as routine treatment for people with cystic fibrosis.