Nasal irrigation

Medical uses

Nasal irrigation is used for a range of sinus and nasal symptoms.

Chronic sinusitis

For chronic sinusitis it can be an effective add-on therapy. It is also reported to be an effective measure against chronic sinus symptoms induced by work-place exposure to sawdust. Further evidence suggests that nasal irrigation causes relief for both hay-fever and the common cold. Nasal irrigation could also be an effective treatment for allergic rhinitis and chronic sinusitis.

Daily nasal irrigation with a salt-water solution (a mixture of 0.9% non-iodized sodium chloride and either purified or filtered water warmed to around 98 degrees F/ 37 degrees C, with or without inclusion of a buffering agent such as sodium bicarbonate) has been recommended as both an add-on and primary treatment in such cases and is preferable to the use of corticosteroids except in the most serious cases of acute bacterial sinusitis. Irrigation should be used with caution in infants, as nasal drops are not widely tolerated.

Treatment guidelines in both Canada and the United States recommend use of nasal irrigation for all causes of rhinosinusitis and for postoperative cleaning of the nasal cavity.

Acute infection

There is tentative evidence for benefit of saline irrigation in acute upper respiratory tract infections such as the common cold and acute sinusitis.

Methods

A simple method requiring no specialized equipment is to snort water from cupped hands, but this clears little more than the nostrils. The application of commercially available saline nasal spray is another simple alternative, but it is relatively inefficient for washing away debris, although it may suffice for simple rehydration of mucous and tissues.

A simple yet effective technique is to pour salt water solution into one nostril and let it run out through the other while the mouth is kept open to breathe, using gravity as an aid. Jala-neti, which means to cleanse the nose with water, is an old yogic technique from India. The container used to administer the saline is called a "neti pot". This process removes mucus and dirt and clears the nose. A second neti technique known as sutra neti uses a piece of string instead of water.

Neti pots are typically made of metal, glass, ceramic or plastic. They rely on gravity, along with head positioning and repeated practice in order to rinse the outer sinus cavities. Typically they have a spout attached near the bottom, sometimes with a handle on the opposite side.

The second method of nasal irrigation is to introduce some form of positive pressure to the water introduced into the sinuses and nasal cavities in order to provide a more complete rinsing without resorting to special techniques, such as holding the head to one side (which is usually difficult with a neck condition). Some products available from pharmacist supply retailers are essentially bottles made of flexible plastic with special tips to fit the nostril. These bottles, when filled with warm salt water solution, can be squeezed to exert positive pressure of the water flowing through the sinuses while the mouth is kept open at all times in order to breathe and prevent snorting the liquid down the throat. Even ordinary plastic water bottles can and have been used, as long as the nozzle will adequately fit a person's nostril. However, neither squeeze bottles nor bulb syringes provide the user with any genuine control over the pressure/volume of solution introduced. To prevent ear pressure or ear infection, you need to make sure the pressure cannot be too high. The diameter of the hole in the center of the nostril fitting cannot be larger than 3 mm. If it is too large, a big wave of liquid can be forced to enter anywhere, such as middle ear, causing ear pain or even ear infection.

Irrigation machines that utilize electric motor-driven pumps are also available. These irrigation devices pump salt water solution through a tube, in connection with a nasal adapter tip designed to seal against the nostril. Some of these machines allow adjustment of water volume/speed by use of an adjustment dial which regulates pump speed and volume per minute. Most of these motorized machines use a pulsatile or pulsating water pumping action at a relatively low, predetermined fixed pulse cyclic rate, designed to match the normal wave rate of healthy, unobstructed nasal cilia. This matched pulse rate is claimed to stimulate the nasal cilia hairs and promote better sinus health, while reducing the severity of allergic reactions. More sophisticated motorized irrigators have two or more pulse cycle settings that adjust the actual pulse cycle (as opposed to a simple volume/speed control, which does not alter the pulse cyclic rate). This design affords the user the option of using a higher pulse cyclic rate when suffering from partially closed sinuses, as in a typical case of acute sinusitis. The efficacy of all motorized pump irrigators has not yet been tested compared to simpler non-motorized mechanical pressure nasal irrigation methods.

Some nasal irrigation systems that apply pressure have an anti-backwash valve to prevent used saltwater solution from flowing back into the nasal cavity. This is particularly important for those people with bacterial or viral infections, such as the common cold or flu. This type of irrigator should be held upright, as in brushing one's teeth, because if the head is tilted sideways, liquid could enter the ear on the lower side and cause an ear infection. This refers to an irrigator that applies pressure, but not to the neti pot, which utilizes only gravity in its application. Neti pots do not allow used solution to flow back into the nasal cavity.

Solutions used

While nasal irrigation can be carried out using ordinary tap water, this is possibly unsafe and additionally can be uncomfortable because it irritates the mucous membranes. Therefore, an isotonic or hypertonic salt water solution is normally used, i.e. water with enough salt to match the tonicity of the body cells and blood. For the same reason, lukewarm water is preferred over cold water, which in addition to irritating nasal membranes can also exaggerate the gag reflex during irrigation. Use of distilled, sterile or previously boiled and cooled water over ordinary tap water is advised. A small amount of baking soda is sometimes employed as a buffering agent to adjust the pH of the irrigating solution to that of the body.

Many pharmacies stock pre-manufactured sachets of pharmaceutical grade salt and baking soda designed to be used with the volume of water their corresponding device uses. Sometimes manufactured solutions such as a lactated Ringer's solution is used. It is also simple to make a salt-baking soda mixture.

Potential allergens (such as iodine) or contaminants (algae, etc.) are to be avoided in the sodium chloride, water, or buffering ingredients. Premanufactured dosages of salt water flushing solutions can be purchased, or the user can mix non-iodized 'kosher' salt, with or without a buffering agent such as sodium bicarbonate or baking soda. (Table salt frequently is iodized, while sea salt may contain algae or other contaminants.)

Optional additives include xylitol which is claimed to draw water into the sinus regions and helps displace bacteria. Xylitol is commonly used to prevent acute otitis media in Europe and dental cavities in the United States, but research into xylitol use in the sinus cavities is lacking. Another nasal irrigation additive is aloe extract, which helps to prevent nasal dryness. Sodium citrate and citric acid help not only to balance the pH, but also to improve the sense of smell.

Adverse effects

The solution used for irrigation should be distilled, sterile or previously boiled due to the risks involved with using potentially contaminated water. If this is done the procedure is generally safe.

Deaths have been reported as a consequence of using Naegleria fowleri-contaminated water for sinus irrigation. Very few cases of Naegleriasis (in the low hundreds) have ever occurred globally; in the United States, despite two 2011 deaths in Mississippi (both from the same treatment plant) no cases have ever been recorded that involve tap water from normal treated supplies where a water heater has raised the temperature above 120 degrees Fahrenheit. Naegleria fowleri in unboiled or otherwise unsterilized water can cause the brain infection primary amoebic meningoencephalitis (PAM), which carries a 95% risk of fatality.

A much more minor adverse result of using the bottle or mechanized types is occasional vomiting from one's gag reflex being triggered by the slightly pressurized water.

Mechanism of action

Saline solutions used in nasal irrigation reduce inflammation through osmosis. Swelling is a major factor in sinus dysfunction. Removal of mucus plays an important role in sinus health, and nasal irrigation facilitates this by flushing out thickened mucus that cannot be handled by the cilia. improving mucociliary clearance and also removing infected material. Damage to the mucociliary transport system is an important factor in the development of sinonasal diseases, leading to a stasis of mucus. The numerous proteins found in nasal mucus include inflammatory mediators, defensins and many whose function is not understood.

In a study with eight healthy volunteers, solution was transported reliably to ethmoid and maxillary sinuses when it was snorted or applied with a squeeze bottle; a nebulizer was significantly less effective. Sphenoid and frontal sinuses were rarely reached, and not at all with the nebulizer.

Flushing the nasal cavity with salt water has been claimed to promote mucociliary clearance by moisturizing the nasal cavity and by removing encrusted material, although there is no clear evidence to support this.

History

The earliest record of nasal irrigation is found in the ancient Hindu practice of Ayurveda whose roots are traced to the Vedas. It was customary to perform jala-neti daily, as part of soucha (personal hygiene according to scriptures). The simplest method of nasal irrigation, that is to sniff water from cupped hands and then blow it out, is also a step in the ablution practices (Wudu) of Muslims.