Ask an answerable question (PICO)：
Acute bronchiolitis is the most common lower respiratory infection in children, and is a major cause for hospitalization in children in the first year after birth. The pathogenesis of bronchiolitis included mucosal inflammation and swelling. The infection can last 2–3 weeks, and it is particularly prone to dyspnea among children under two years old.
According to the 2014 American Academy of Pediatrics Bronchiolitis guideline, vapor treatment is one of the most commonly used treatments, which helps to dilute respiratory secretions and promote sputum excretion. However, the effectiveness and clinical application of different concentration of the solution for vapor inhalation is still controversial. Inhaled hypertonic saline (HS) has recently been shown to be a favorable therapy, because of its facility to draw fluid from the submucosa and adventitial spaces, decreasing airway edema. The aim of this systematic review and meta-analysis was to evaluate the efficacy and safety of HS in the implementation of vapor treatment among children with bronchiolitis.
The Method and Analysis of Literature Review：
In total, 2854 children from 19 publications were included. All studies compared HS against a NS or placebo. The risk of bias was “some concern” using RoB 2.0, and “moderate” based on GRADE methodology. The risk of bias was rising from blinding of participants and personnel and incomplete outcome data.
Compared to the control group, the HS group exhibited significantly decreased the length of hospital stay 0.74 days (95% CI -1.2, -0.3, I²= 69%), reducing the level of clinical severity score (CSS) (MD -1.1, 95% CI -1.7, -0.6), and the score of respiratory distress assessment instrument (RDAI) (MD -0.6, 95% CI -0.9, -0.2). A high heterogeneity was noted due to diversity of population, intervention (inhalation time and dose), assessment tools and the time point of measurement. No adverse events were reported in the included studies.
Critical Appraisal：
In total, 2854 children from 19 publications were included. All studies compared HS against a NS or placebo. The risk of bias was “some concern” using RoB 2.0, and “moderate” to“high” based on GRADE methodology. The risk of bias was rising from blinding of participants and personnel and incomplete outcome data.
Compared to the control group, the HS group exhibited significantly decreased the length of hospital stay 0.74 days (95% CI -1.2, -0.3, I²= 69%), reducing the level of clinical severity score (CSS) (MD -1.1, 95% CI -1.7, -0.6), and the score of respiratory distress assessment instrument (RDAI) (MD -0.6, 95% CI -0.9, -0.2). A high heterogeneity was noted due to diversity of population, intervention (inhalation time and dose), assessment tools and the time point of measurement. No adverse events were reported in the included studies.
Results, Conclusions and Recommendations：
We conclude that nebulized with 3% saline solution is effective in decreasing the length of hospital stay and the severity of symptoms as compared with 0.9% saline solution among children with acute bronchiolitis. Further rigor randomize controlled trails with large sample size are needed.
