Inhaled Hypertonic Saline for Cystic Fibrosis

Inhaled Hypertonic Saline Thins Secretions by Osmosis

Nurse giving sick boy stuffed animal in hospital, cropped. Credit: PhotoAlto/Laurence Mouton

Inhaled hypertonic saline is one of the newer treatment options for cystic fibrosis (CF). A group of Australian researchers discovered the benefits of hypertonic saline when they noticed that surfers with CF had better outcomes than people with CF who did not surf. The researchers believed that inhaling the salty mist of ocean water during surfing was the reason that surfers had fewer respiratory flare-ups than their nonsurfing counterparts had, and a study confirmed those findings.

The researchers published the results of their study in 2006, and ever since then, hypertonic saline has been available as a treatment option to many people with CF.

What is Hypertonic Saline?

Normal saline is a salt-water solution that contains the same concentration of salt as our own body fluids. Hypertonic saline is any salt-water solution that contains a greater concentration of salt than does normal saline, and therefore a greater concentration of salt than our body fluids. Normal saline solution is 0.9% salt. The hypertonic saline used in CF treatment is 7% salt.

Hypertonic saline is administered to people with cystic fibrosis twice daily.

How Hypertonic Saline Works

Fluids transfer in and out of cells by a process called osmosis, where fluids with lower salt concentrations flow across the cell membrane to mix with fluids with higher salt concentration. Simply stated, osmosis means that water follows salt.

In CF treatment, a machine called a nebulizer aerosolizes the hypertonic saline solution. The saline mist is inhaled and settles in the airways. Because  hypertonic saline has a much greater concentration of salt than normal body fluids, it draws water from the cells in to the airway. The water mixes with the thick mucus in the airway, making it thinner and easier to cough out or expectorate.

(Expectorate is medical jargon for coughing out mucus.)

Research examining the use of hypertonic saline in people with cystic fibrosis suggests that this treatment may result in small improvements in pulmonary function and fewer attacks or exacerbations. Nevertheless, the effect of treatment varies among individuals, and some people may experience more relief than do others.

Are There Any Adverse Effects of Hypertonic Saline?

Hypertonic saline is not a drug, but it does cause changes in the body that can have some unpleasant effects. Some people using hypertonic saline have experienced an increase in coughing, sore throats or chest pain caused by tissue irritation.

Isn’t Saline Just Salt Water? Can it Be Made at Home?

No. The concentration of salt must be precise, and this would be difficult to accomplish in a homemade solution. More importantly, the solution must be sterile to prevent introducing potentially life-threatening bacteria in to the airways.

Source:
Chesnutt MS, Prendergast TJ. Pulmonary Disorders. In: Papadakis MA, McPhee SJ, Rabow MW. eds. Current Medical Diagnosis & Treatment 2016. New York, NY: McGraw-Hill; 2016. Accessed January 23, 2016.

Donaldson, S.H., et al. “Mucus Clearance and Lung Function in Cystic Fibrosis with Hypertonic Saline”. 2006. New England Journal of Medicine 354(3): 1848-1851. 4 August, 2008.

 

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