Hypertonic saline is used for nebulization in various respiratory conditions – both in adults and children. Patients with Cystic fibrosis (CF) are required to use it many times a day for airway clearance to hydrate the viscid mucus in their airways [1].

In India, the only formulation of hypertonic saline available is a 3% solution dispensed in 100 mL sterile packs/bottles. On an average, each CF patient reuses the same bottle costing approximately Rs.100 for 5 to 6 days. This leads to a unique problem of contamination of the solution with bacteria, including P. aeruginosa, the very organism against which much of the antibiotic treatment is directed at, in CF patients.

Pseudomonas is ubiquitous in the environment and thrives on wet surfaces. Lack of adequate microbial clearance and pro-inflammatory environment, which are characteristic of CF airways, sets the stage for a downhill course once it colonizes the CF airways. In one study, the 8-year risk of death was found to be 2.6 times higher in patients colonized with　Pseudomonas than in those without [2]. Isolation of P. aeruginosa from the airway secretions of a 2-month-old baby, 3 weeks after initiation of hypertonic saline nebulization prompted us to check the nebulization solution for bacterial contamination.

We performed surveillance cultures on 12 selected samples of hypertonic saline drawn from the bottles/packs being reused by CF patients. Eight of the 12 samples (66%) were contaminated, 4 growing multiple bacteria. Pseudomonas strains isolated were P. aeruginosa, P. putida and P. stuzeri; one isolate from each of the three contaminated samples. Other bacteria were non-fermenting Gram negative bacilli (other than Pseudomonas and Acinetobacter), Klebsiella, Citrobacter diversus, Acinetobacter haemolyicus and coagulase-negative Staphylococcus.

Contaminated hypertonic saline solution can be a source of infection not only for CF patients, but also for those whose airway defenses are altered due to other reasons. To overcome this problem, we now pack 150 mg of pharmaceutical grade sodium chloride powder, which the caregiver can dilute with commercially available ‘sterile water for injection’ dispensed in 5 mL packs. We tested this freshly-mixed solution to be 3% NaCl and bacteriologically sterile. Individually weighing and packing sodium chloride salt imposes a high workload on our pharmacy service and may be difficult to replicate. However, it is an interim arrangement that can be practiced till smaller single use 5- to 10 mL aliquots of hypertonic saline are made commercially available in India at affordable costs.

Acknowledgements: Dr Joy Sarojini Micheael, Department of Microbiology contributed to the laboratory work, Mr Abel Regi, Pharmacy services has contributed to conduct of work and Mr Hari Pratap Reddy, Paediatric respiratory therapist for data collection and analysis.

Contributors: SV: conception of the idea, design of the work and manuscript writing; WR: contributed significantly to design and conduct of the work and critical review of the manuscript.

Funding: None; Competing interest: None stated.

1. Elkins M, Robinson M, Rose B, Harbour C, Moriarty C, Marks G, et al. A controlled trial of long-term inhaled hypertonic saline in patients with cystic fibrosis.　N Engl J Med. 2006;354:229-40.

2. Emerson J, Rosenfeld M, Mcnamara S, Ramsey B, Gibson RL. Pseudomonas aeruginosa and other predictors of mortality and morbidity in young children with cystic fibrosis. Pediatr Pulmonol. 2002;34:91-100.