Saline nasal irrigation for acute upper respiratory tract infections
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
The primary objective of this review is to assess the efficacy of saline nasal irrigation for symptom reduction in patients with acute URTIs.
Background
Description of the condition
Acute upper respiratory tract infections (URTIs) are characterised by infection involving the upper airways ‐ the nose, sinuses, larynx, and pharynx. Examples of acute URTIs include the common cold, influenza, rhinitis, sinusitis, laryngitis, pharyngitis, tonsillitis and otitis media. Acute infections are those with symptoms lasting up to 28 days (Meltzer 2006).
Acute URTIs are common. Symptoms of upper respiratory tract infections, such as fever, sore throat, and nasal congestion, can be uncomfortable and debilitating, and are a major cause of employee absence in the workforce. The economic impact of the common cold alone on workplace absenteeism is estimated to be in the billions of dollars (Bramley 2002).
Description of the intervention
Usual treatments for URTIs include antipyretic and analgesic drugs, mucolytics, expectorants and decongestants. While acute URTIs are mainly caused by viruses, antibiotics are often prescribed. This may lead to increased antibiotic resistance (Nyquist 1998), as well as being unnecessary for the patient.
Saline irrigation is believed by some to alleviate upper respiratory symptoms by clearing excess mucous, reducing post‐nasal drip and associated cough, reducing congestion and improving breathing. It is reported to improve mucociliary clearance by increasing the frequency of nasal ciliary beating (Talbot 1997), and is sometimes used as an effective treatment for chronic sinusitis and allergic rhinitis (Tomooka 2000). It has been used alone or as an adjunct to other treatment, such as oral antihistamines.
Why it is important to do this review
If saline nasal irrigation is effective for acute URTIs, the treatment could potentially substantially reduce its burden of disease and workplace absenteeism. It might reduce the over‐prescription of antibiotics. The existing literature contains different methods of nasal saline delivery (Passali 2005), and different dilutions of saline (Adam 1998). One literature review (Papsin 2003) found that most trials were very small, and some were uncontrolled.
While this review will focus on acute URTIs, another Cochrane review protocol (Harvey 2007) addresses nasal saline irrigation for chronic rhinosinusitis.
Objectives
The primary objective of this review is to assess the efficacy of saline nasal irrigation for symptom reduction in patients with acute URTIs.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials (RCTs) will be included where topical nasal saline treatment is compared with at least one other intervention. Studies that are non‐RCTs or not comparative will not be included. Trials involving patients with chronic URTIs or allergic rhinosinusitis will not be included. Studies trialling another therapy, where saline irrigation is used as a control treatment, will be considered for inclusion.
Types of participants
Adults and children of both genders diagnosed with acute URTIs, featuring nasal and/or sinus symptoms. Studies involving patients with allergic respiratory symptoms, chronic respiratory infections, or chronic diseases with respiratory features, such as cystic fibrosis, or recovering from sinus surgery, will be excluded. Participants must have acute infections, involving symptoms for less than 12 weeks. Types of acute URTIs will include rhinosinusitis, pharyngitis, otitis media, tonsillitis, common cold, and influenza.
Types of interventions
Any intervention using nasal lavage, irrigation, or similar topical nasal liquid saline treatment, compared with a placebo, with other standard treatment, or nasal saline plus standard treatment compared with standard treatment alone. Comparative treatments may be different topical medications or other treatment methods. Studies using atomised or nebulised saline may be considered if other inclusion criteria are met. Trials of all types of topical saline treatments, including isotonic and hypertonic solutions, as well as commercially available saline preparations, will be considered for inclusion.
Types of outcome measures
Primary outcomes
-
Improvement of respiratory related symptoms (nasal discharge, congestion, sneezing, headache);
-
duration and severity of symptoms; and
-
nasal symptom score.
Secondary outcomes
-
Adverse events associated with treatment;
-
time to resolution of illness; and
-
rhinomanometric resistance and nasal volume.
Search methods for identification of studies
Electronic searches
We will search the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, latest issue), MEDLINE (1966 to present), EMBASE (1976 to present), CINAHL (Cumulative Index to Nursing & Allied Health Literature) (1982 to present), AMED (Allied and Complementary Medicine) (1985 to present) and LILACS (Latin American and Caribbean Health Sciences Literature).
The following search terms will be used.
"Respiratory Tract Infections" or "Rhinitis" or "Common Cold" or "Pharyngitis" or "Sinusitis" or "Laryngitis" or sinusitis or laryngitis or pharyngitis or rhinitis or "runny nose" or "common cold" or flu or rhinorrhea or rhinorrhoea or rhinosinusitis
AND
"Saline" or "Saline Solution" or saline or salt or "sodium chloride"
AND
"Irrigation" OR irrigat* OR lavage OR wash* OR rinse OR rinsing OR douch*
AND
"nose" or "nasal"
Searching other resources
There will be no language or publication restrictions. The Australian Clinical Trial Register database (http://www.actr.org.au/) and the U.S. National Institutes of Health (http://www.clinicaltrials.gov) will also be checked for relevant studies.
Evidence of any adverse effects of saline nasal irrigation will be sought from other sources, including the U.S. Food and Drug Administration's MedWatch (www.fda.gov/medwatch), the UK Medicines Control Agency (http://www.open.gov.uk/mca), and the Australian Adverse Drug Reactions Bulletin (http://www.health.gov.au).
Bibliographies will be searched for further relevant studies and trial authors will be contacted for any recent unpublished work.
Data collection and analysis
Selection of studies
Two review authors will independently identify studies as potentially relevant and select trials based on the title and abstract of paper.
Data extraction and management
Two review authors will independently extract and summarise data using a data extraction sheet. Trial authors will be contacted to provide any necessary missing data, where possible. A data extraction sheet will be used to synthesise the data from the studies. Data to be extracted will include:
-
year and country of study;
-
study population;
-
methodological quality of study,
-
type of saline solution used, and
-
any adverse events and outcomes.
Assessment of risk of bias in included studies
Trials under consideration will be assessed for methodological quality and for appropriateness for inclusion without consideration of their results. Data from included trials will be processed, as described in The Cochrane Handbook for Systematic Reviews of Interventions (HIggins 2006). The quality assessment will be undertaken by an evaluation of the following components for each included study, since there is some evidence that these are associated with biased estimates of treatment effect.
-
The method of generation of the randomisation sequence; if it delivered a known chance allocation to each given group, but individual allocation could not be anticipated.
-
The method of allocation concealment ‐ it will be considered 'adequate' when the assignment could not be foreseen.
-
Who was masked or unmasked to the intervention (participants, clinicians, outcome assessors);
-
Participants lost to follow up in each arm of the study (split into post‐randomisation exclusions and later losses if possible), and whether participants were analysed in the groups to which they were originally randomised (intention‐to‐treat).
In addition, aspects related to follow up, participants lost to follow up, protocol violations, and sample size determinations will be collected. The information will be recorded in a table of quality criteria and a description of the quality of each study will be given based on a summary of these components.
Unit of analysis issues
We will use an intention‐to‐treat analysis. Data will be presented as relative risk (RR) or odds ratio with 95% confidence interval (CI) for dichotomous outcomes, or as standardised mean difference with 95% CI for continuous outcome measures. If insufficient data exists for results to be pooled, evaluation of data will be applied to each individual study, using RR or mean difference.
Consideration will be given to what clinical significance may be associated with any statistically significant difference in outcome measures, that is whether a statistically significant effect is large enough in reality to also be of clinical significance.
Assessment of heterogeneity
Statistical analysis of heterogeneity and effect size will be executed using Review Manager 4.2. Meta‐analysis, using a random‐effects model, will be performed if there is evidence of heterogeneity, defined as an I‐squared (I2) value > 50%. A sub analysis of different dilutions of saline used for nasal irrigation will be performed if there are sufficient data.
