Nasal irrigation

A man flushing his nose with a neti pot.

Nasal irrigation or nasal lavage is the personal hygiene practice in which the nasal cavity is washed to flush out excess mucus and debris from the nose and sinuses. It has been practised in India for centuries as one of the disciplines of yoga. Some clinical tests have shown that this practice is safe and beneficial with no significant side effects,. Nasal irrigation in a wider sense can also refer to the use of saline nasal spray or nebulizers to moisten the mucus membranes.

The simplest technique is to snort water from cupped hands. Spraying the solution into the nostrils is more convenient, but also less effective. The most effective methods ensure that the liquid enters through one nostril and then either runs out of the other nostril or goes through the nasal cavity to the back of the throat from where it may be spat out. The necessary pressure comes from gravity, from squeezing a plastic bottle or a syringe, or from an electrical pump.

Warm salt water solution is commonly used, often with sodium bicarbonate as a buffering agent. Optional additives include xylitol which is claimed to draw water into the sinus regions and helps displace bacteria. The use of xylitol in products such as chewing gum is there to reduce bacterias' ability to cling to surfaces, this is a supposed benefit in its use in nasal irrigation.

Benefits and uses

Common nose rinse device available at drug stores

Nasal irrigation is used to treat a wide range of chronic sinus symptoms; for chronic rhinosinusitis it is an effective adjunctive therapy. According to patient self-reports it improves quality of life and reduces use of medication, including antibiotics. Long-term daily use, however, been linked to increased frequency of acute rhinosinusitis episodes in one trial. It is also 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. The use of nasal irrigation for the related conditions of asthma, nasal polyposis and rhinitis of pregnancy has not been assessed but the symptoms of these conditions are expected to be alleviated in a similar way.

Daily nasal irrigation with salt water solution (a mixture of 0.9% non-iodized sodium chloride and either purified or tap water warmed to around 98 degrees F, with or without inclusion of a buffering agent such as sodium bicarbonate) is recommended as both an adjunctive and primary treatment in such cases and is preferable to the use of antibiotics or corticosteroids except in the most serious cases of acute bacterial sinusitis which should be immediately referred to an otolaryngologist. In several countries, over-the-counter medicines for coughs and colds are no longer sold for infants under the age of two. Nasal irrigation is an alternative for relieving the symptoms of such young patients.

Flushing the nasal cavity with salt water is believed to promote mucociliary clearance by moisturizing the nasal cavity and by removing encrusted material, although there is no clear evidence to support this. In proper proportion, nasal salt water solution with slight acidic ph functions as an anti-bacterial irrigant. The flow of salt water through the nasal passage flushes the dirt, airborne allergens (dust and pollen), pollutants and bacteria-filled mucus.

Salt water flushing also loosens and thins the mucus, making it easier to expel. Without this build up of mucus, the tiny cilia, or hairs in the nasal passage are able to function more efficiently, pushing excess mucus either to the back of the throat or to the nose to be expelled.

The procedure has been used safely for both adults and children, and has no documented serious adverse effects as long as no potential allergens (such as iodine) or contaminants (algae, etc.) are used 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). Proponents of nasal irrigation include many allergy and sinus sufferers, some of whom have claimed anecdotally to rely less on other medications and/or fewer doctor visits. Treatment guidelines in both Canada and the United States now advocate use of nasal irrigation for all causes of rhinosinusitis and for postoperative cleaning of the nasal cavity.

Methods

The simplest method, in that it does not require any equipment, is to snort water from cupped hands. 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. This is an old Ayurvedic technique known as jala neti, and the container used to administer the saline is called a neti pot. (Neti is Sanskrit for "nasal cleansing". A second neti technique known as sutra neti uses a piece of string instead of water.)

Neti pots are traditionally made of metal, glass or ceramic, and rely on gravity alone, along with head positioning and repeated practice in order to rinse the outer sinus cavities. Some users are able to use neti pots without problems, while the sideways positioning of the head can induce vertigo in others. A more advanced variation of the technique (known in yoga as "Vyutkrama Kapalbhati") involves pouring the same salt water solution into one nostril while the other is held closed, so that the solution runs out of the mouth. It is more challenging than the basic version (care must be taken to keep the saline solution out of the throat and to suppress possible vomiting reflex), but it allows to achieve more thorough irrigation of the nasal cavity and the sinuses.

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 resort to special techniques, such as holding the head to one side. 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.

Yet another type of product, the Nasaline irrigator, utilizes an oversized syringe with an injector-type plunger in place of the bulb. Invented by a group of Swedish ENT specialists, the Nasaline contains a specially designed tip intended to better atomize the salt water through a swirling action at a predetermined, nonadjustable velocity as it is forced through the sinuses by the injector's plunger.

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.

Solutions used for nasal irrigation

Nasal irrigation can be carried out using ordinary tap water, but this is generally felt to 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 at least match the tonicity of the body cells. 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. Similarly, a small amount of baking soda is frequently mentioned as an optional buffering ingredient to adjust the pH value to that of the body. A typical home recipe for an isotonic solution consists of 1⁄2 litre (1 pint) of water, 2.5 to 5 millilitres (1/2 to 1 teaspoon) of salt and optionally another 2.5 to 5 millilitres of baking soda for an isotonic solution. For a hypertonic solution the amount of salt would be doubled or tripled.

Medical sources generally agree that iodised table salt is not acceptable, and that pickling salt (or kosher salt, though care is needed to ensure no additives and that it dissolved completely) is preferred because it also does not contain any other additives such as anticaking agents - Baking powder is also not an acceptable substitute for baking soda. Most sources advise that tap water should be boiled for several minutes to ensure sterility before it is cooled and used, but it is not clear whether this is really necessary.

Sometimes manufactured solutions such as lactated Ringer's solution are used instead of the basic recipe, or patients dissolve powder from manufactured sachets in a prescribed amount of water. Occasionally further substances are added to the basic recipe, such as antibiotics, antifungal drugs or xylitol.

Mechanism of action

The precise reasons for the efficacy of nasal irrigation are not well understood, although it is clear that the removal of mucus plays an important role. 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. Thus hypotheses include that nasal irrigation may decrease inflammation through the removal of mucus, that it may improve mucociliary clearance, and that it may remove thickened mucus that cannot be handled by the cilia.

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.

See also

• Post-nasal drip

External links

• Mayo Clinic instructional video
• University of Wisconsin instructions, study and video
• Inter-Neti, information website, covers clinical evidence and explains proposed mechanisms of action
• Nasal irrigation with a plastic syringe