Take spray with a pinch of salt

“A salt water nasal spray can help children ward off colds and flu,” reported the Daily Express today. The paper added that a recent study in 401 six to 10-year-old children with colds or flu compared a nasal spray made from Atlantic seawater with standard treatments (aspirin, antibiotics, or decongestants) and found that the spray reduced the children’s blocked noses. The children who continued to use the spray after they recovered also “slashed” their risk of getting ill again from 75% to 31%.

This story is based on a trial that looked at the effects of adding a salt-water (saline) nasal spray wash to the normal treatments used for colds in children. Although the study is relatively large, limitations in its design suggest that we should wait for confirmation of these results before drawing firm conclusions about the benefits of saline nasal washes. Conventional treatments were used with the nasal spray within the study, and this course is still recommended.

Where did the story come from?

Dr Ivo Slapak and colleagues from hospitals in the Czech Republic and Pharma Projects Ltd conducted the research. The study was funded by Goemar Laboratoires La Madeleine, the company that makes the nasal spray used in the study. The sponsor was involved in study design, but not in analysis or interpretation of the data in the study.

The study was published in the peer-reviewed medical journal: Archives of Otolaryngology, Head and Neck Surgery.

What kind of scientific study was this?

This was an unblinded randomised controlled trial looking at the effects of a nasal wash made from modified seawater in children with colds or flu.

The researchers enrolled 401 children aged six to 10 who visited eight paediatric outpatient departments with colds or flu. All patients received standard treatment for this illness. The children were also randomly assigned to one of three nasal spray groups (along with standard treatment) or standard treatment alone (control) based on the order in which they attended the clinic.

The nasal wash was a commercially available product made from Atlantic Ocean seawater. The three groups varied in the strength of the spray used; medium jet flow nasal spray (nine millilitres of saline per application per nostril), fine spray nasal spray (three millilitres per application per nostril), or nose and eye wash with a fine spray (three millilitres per application per nostril). The saline spray was used six times a day while the child was ill, and then three times a day afterwards.

Standard treatments included medications for fever, decongestant nasal sprays, drugs to break down mucus, and antibiotics if needed. Details about the length of the child’s illness, other diseases and medications were recorded.

The children were then followed up for 12 weeks (January to April 2006), and assessed four times in this period; twice in the first three weeks (considered the treatment phase of the study), and twice after this (considered the prevention phase). The children’s symptoms, time off school, and days of sickness were assessed when they entered the study and at subsequent visits.

Symptoms were rated on scales ranging from one (no symptoms) to four (worst symptoms). Children in the saline spray group were also asked about their experience of using the wash. At the end of the study, the bottles of saline wash were weighed to estimate how much of the spray had been used. Only those children who had used 75% or more of the prescribed dose were included in the analyses (only one child was excluded on this basis). Researchers then compared symptoms, time off school, days of illness, and recurrence of illness between the groups.

What were the results of the study?

The researchers found that nasal and throat symptoms cleared faster in the saline spray groups than in the control group. By their first follow-up visit, the saline spray groups together had improved nasal breathing, sore throat, and amount and type of nasal secretions compared with the control group. Other symptoms, including dry and productive cough, sneezing, itching, and loss of smell or taste did not differ between the groups.

The saline spray groups also used less nasal decongestants and medications to break down mucus than children in the control group. At eight weeks after enrolment, in the prevention part of the study, the saline spray groups together had improved sore throat, cough, nasal breathing and secretion compared to control, but other symptoms did not differ. The saline groups also reported fewer illness days and absences from school.

About nine out of every 100 children reported complaints with the nasal spray at the treatment phase, and two out of 100 in the prevention phase. Complaints included the strength of the medium jet spray, and of burning and bitter taste. About one in 100 children experienced nosebleeds with the nasal spray.

What interpretations did the researchers draw from these results?

The saline spray speeded up recovery from some nasal symptoms compared to standard treatments, and reduced the risk of subsequent nasal infections.

What does the NHS Knowledge Service make of this study?

Although this was a relatively large study, it does have its limitations:

• The method used to assign children randomly into the groups did not appear to be ideal. The doctors reportedly “randomised” the children “based on the sequence of their appearance in the clinic”, and this method could have lead to imbalance between the groups. However, the authors reported that groups were “comparable” in the characteristics they looked at when they enrolled. Ideally, randomisation should be performed by someone independent using computer generated randomisation sequences. Each allocation should be concealed from the researchers, so that they cannot influence the randomisation sequence.
• It is not clear whether the scales that the researchers used to measure symptoms had been tested to make sure they accurately reflected symptoms and could be applied in a consistent way by different doctors.
• The accuracy of the process of asking parents to remember their child’s days of illness or absence from school is unreported.

These limitations suggest that further studies need to confirm these results before firm conclusions can be drawn about the benefits of saline nasal washes.

Sir Muir Gray adds...

My mother used to make me inhale steam from a basin with a towel draped over my head to maximise the Turkish bath effect; a little bit of moisture always brings relief.