Salt Solutions For Nasal Irrigation

The salt solution used to perform nasal irrigation has a huge effect on the comfort of the procedure as well as the health benefits obtained. All salt solutions will, of course, mechanically clear out excess mucus at the time nasal irrigation is performed, but nasal irrigation can have a much longer lasting impact depending on the salt solution used. There are two main ways in which irrigation solutions vary, the tonicity (salinity) and which, if any, additives are added.

Tonicity

The tonicity (salt concentration) has a huge impact on the comfort of performing nasal irrigation. Many people are put off of the idea of nasal irrigation simply because water has gone up their nose when swimming, and it has hurt. One reason that it hurts is that the salt concentration of swimming pool water is much lower than that of human tissue. Pool chemicals and water pollution are other reasons. Solutions that match the salinity of human tissue (~0.9%) are known as isotonic and solutions of greater concentration are known as hypertonic.

Plain water, and salt solutions that are weaker than isotonic, can be very uncomfortable. They have no known health benefits and are therefore not recommended. Solutions traditionally used for jala neti are roughly isotonic but hypertonic solutions can also be used.

Isotonic

There is evidence that nasal irrigation with isotonic saline solution can benefit those suffering from chronic sinusitis by reducing nasal secretions and post-nasal drip. It has also been found to reduce sinus and nasal symptoms from air-borne irritants such as wood dust.

There are conflicting opinions about how many hours after nasal irrigation with isotonic saline the mucociliary clearance mechanism continues to work.

However, nasal irrigations with isotonic saline have been shown to decrease the concentrations of the inflammatory mediators histamine and leukotriene C4, in patients with allergic rhinitis for six hours and four hours respectively, after each irrigation.

Advantages

• Most comfortable
• Associated with few side-effects

Disadvantages

• Less effective for treating sinus and nasal conditions

Hypertonic

It is less comfortable to use than isotonic solutions and is known to cause a stinging or burning sensation in some people. It is also associated with more side effects than isotonic saline, including:

• Nasal irritation
• Headache
• Watering eyes
• Nosebleeds
• Post nasal drip

In general, nasal irrigation is well tolerated and these side effects, when encountered, are not usually sufficiently bothersome to stop therapy. The best compromise between the health benefits and the side effect is to reduce the salinity and/or the frequency of use.

On the other hand, nasal irrigation with hypertonic solutions is known to have far greater health benefits compared with isotonic saline. Hypertonic solutions are effective for treating a variety of sinus and nasal conditions, including allergic rhinitis, ageing rhinitis, atrophic rhinitis, cough and sinusitis. Hypertonic solutions have also been able to alleviate the nasal congestion, headaches and frontal pain and pressure associated with sinusitis. Hypertonic saline has been shown to reduce the use of medications such as antibiotics and nasal sprays in patients with sinusitis, to improve mucociliary clearance, mucus flow, and may reduce inflammation. It has also been shown to reduce sinus-related quality-of-life (QOL) scores.

Advantages

• More effective for treating sinus and nasal conditions
• Improves mucociliary clearance
• May actively reduce inflammation

Disadvantages

• Less comfortable
• Associated with more side-effects

	Isotonic	Hypertonic
Most comfortable	Yes	No
Least side-effects	Yes	No
Clears away mucus	Yes	Yes
Effective for allergic rhinitis	Yes	Yes
Improves mucociliary clearance	No	Yes
Believed to reduce inflammation	No	Yes
Most effective for sinus and nasal symptom relief	No	Yes

Additives

pH buffers

Because saline is slightly acidic (isotonic solutions have a pH of around 6.4 compared to the pH of pure water that is 7) many people believe it is best to buffer the saline solution to be slightly alkaline so that it is more similar to sinus and nasal mucus (pH ~8). This can be achieved by adding a pH buffering agent to the solution such as sodium bicarbonate (baking soda). The addition of a buffering agent does not seem to affect mucociliary clearance but may reduce discomfort in some people.

Antiseptic & mucolytic agents

One study has investigated the effect of adding antiseptic and mucolytic agents to saline. Mucolytic agents break down thick mucus. The investigators added to the saline solution the antiseptic, benzodedecinium and the mucolytic, oleosorbate. This modified solution was used on patients who had undergone endoscopic surgery for nasal polyps. No significant effect on either crust removal, of the severity of reported symptoms was found when compared with normal saline solution.

Ephedrine

Ephedrine, amongst other things, is a vasoconstrictor (causes blood vessels to narrow) and can be administered topically to the nasal passages to work as a decongestant. In a study that investigated the efficacy of isotonic saline with added ephedrine (1%) on sufferers of allergic rhinitis, a significantly greater improvement in symptom scores compared to normal isotonic saline without added ephedrine was found. However, the researchers do not advocate regular use of ephedrine solutions for prolonged periods. When administered systemically and in high doses, ephedrine can have serious side effects and is only available on prescription in the UK.

Table salt additives

Table salt usually contains anti-caking agents. It is not recommended to perform nasal irrigation with a solution containing anti-caking agents and so care must be taken when choosing a salt. It is also important that the salt is non-iodised. Sea, pickling and kosher salt should all be free of these additives and suitable for nasal irrigation solutions. Specially prepared sachets of salt - often sold with neti pots - and proprietary ready mixed concentrated solution are the most convenient. By using sachets or liquid concentrate it is easy to make a solution of the desired tonicity.