Review question
Does the addition of nasal saline spray or wash to usual care or placebo reduce the severity of symptoms or speed the recovery of adults and children with cold and flu symptoms that have been present for less than four weeks?
Background
Acute upper respiratory tract infections (URTIs) include colds, influenza and infections of the throat, nose or sinuses. They are usually self limiting viral infections, though sometimes symptoms may persist for many weeks beyond the clearance of the initial infection, with or without establishment of secondary bacterial infections. The aim of treatment is predominantly for relief of symptoms, though some treatments may have a role in reducing the duration of post-viral symptoms, such as cough. Saline nose spray and larger volume nasal washes have become more popular as one of many treatment options for URTIs, and they have been shown to have some effectiveness for chronic sinusitis and following nasal surgery. However, little is known about their effectiveness in the treatment of acute URTI or which symptoms they may be effective for.
Study characteristics
We identified five studies, with a total of 749 participants enrolled and 565 participants providing data, which addressed the research question and met the inclusion criteria. They all compared saline irrigation with routine care or other nose sprays. These studies covered a wide range of ages, countries, sample sizes, dosing methods and frequency, and time since onset of URTI symptoms. They were also highly variable in their design and the symptoms that were measured. This is not surprising due to the lack of consistent measures of URTI symptoms and signs. This resulted in very few common outcome measures that could be combined across these five studies. The evidence is current to August 2014.
Key results
The two additional studies included since the original systematic review have not contributed data of sufficient size or quality to materially change the original findings. Only the largest study, which studied 401 children aged 6 to 10 years, found significant reductions in a number of symptoms, including nasal secretions, sore throat, nasal breathing score and nasal obstruction, as well as reduced use of additional nasal decongestant medications. It also reported a significant improvement in the health status score. There was a reduction in the outcome of time to resolution of symptoms, which was reported in two trials on adult participants, but the difference was not clinically significant. Nasal saline is safe but may cause minor adverse effects, such as irritation or a burning sensation, particularly with products using higher flows or concentrations.
Quality of the evidence
Most studies were small and had significant shortcomings in the design or implementation of the research. Further studies, preferably larger in size and using common outcome measures, are needed to establish the potential for the role of nasal saline irrigation in reducing the severity and duration of acute URTI symptoms, secondary infections and possibly antibiotic usage.
Nasal saline irrigation possibly has benefits for relieving the symptoms of acute URTIs. However, the included trials were generally too small and had a high risk of bias, reducing confidence in the evidence supporting this. Future trials should involve larger numbers of participants and report standardised and clinically meaningful outcome measures.
Acute upper respiratory tract infections (URTIs), including the common cold and rhinosinusitis, are common afflictions that cause discomfort and debilitation and contribute significantly to workplace absenteeism. Treatment is generally by antipyretic and decongestant drugs and sometimes antibiotics, even though most infections are viral. Nasal irrigation with saline is often employed as an adjunct treatment for URTI symptoms despite a relative lack of evidence for benefit in this clinical setting. This review is an update of the Cochrane review by Kassel et al, which found that saline was probably effective in reducing the severity of some symptoms associated with acute URTIs.
To assess the effects of saline nasal irrigation for treating the symptoms of acute URTIs.
We searched CENTRAL (2014, Issue 7), MEDLINE (1966 to July week 5, 2014), EMBASE (1974 to August 2014), CINAHL (1982 to August 2014), AMED (1985 to August 2014) and LILACS (1982 to August 2014).
Randomised controlled trials (RCTs) comparing topical nasal saline treatment to other interventions in adults and children with clinically diagnosed acute URTIs.
Two review authors (DK, BM) independently assessed trial quality with the Cochrane 'Risk of bias' tool and extracted data. We analysed all data using the Cochrane Review Manager software. Due to the large variability of outcome measures only a small number of outcomes could be pooled for statistical analysis.
We identified five RCTs that randomised 544 children (three studies) and 205 adults (exclusively from two studies). They all compared saline irrigation to routine care or other nose sprays, rather than placebo. We included two new trials in this update, which did not contribute data of sufficient size or quality to materially change the original findings. Most trials were small and we judged them to be of low quality, contributing to an unclear risk of bias. Most outcome measures differed greatly between included studies and therefore could not be pooled. Most results showed no difference between nasal saline treatment and control. However, one larger trial, conducted with children, did show a significant reduction in nasal secretion score (mean difference (MD) -0.31, 95% confidence interval (CI) -0.48 to -0.14) and nasal breathing (obstruction) score (MD -0.33, 95% CI -0.47 to -0.19) in the saline group. However, a MD of -0.33 on a four-point symptom scale may have minimal clinical significance. The trial also showed a significant reduction in the use of decongestant medication by the saline group. Minor nasal discomfort and/or irritation was the only side effect reported by a minority of participants.