The Cochrane Library and the Treatment of Bronchiolitis in Children: An Overview of Reviews

Background Bronchiolitis describes a viral inflammation of the bronchioles in the lower respiratory tract that is typically caused by infection with respiratory syncytial virus (RSV). Bronchiolitis is characterized by high morbidity and affects approximately one in three infants. Children are currently treated with a variety of therapies that may be ineffective or even harmful; potential therapies include antibiotics, bronchodilators, chest physiotherapy, epinephrine, extrathoracic pressure, glucocorticoids, heliox, hypertonic saline, immunoglobulin, inhaled corticosteroids and oxygen therapy. Objectives This updated overview of reviews aims to synthesize evidence from the Cochrane Database of Systematic Reviews (CDSR) on the effectiveness and safety of 11 pharmacologic and non‐pharmacologic treatments to improve bronchiolitis symptoms in outpatient, inpatient and intensive care populations. Methods The CDSR was searched using the term ‘bronchiolitis’ restricted to the title, or keywords for all systematic reviews examining pharmacologic or non‐pharmacologic interventions for the treatment of bronchiolitis in infants and children. Data were extracted, complied into tables, and synthesized using qualitative and quantitative methods. Main Results For outpatients with bronchiolitis (defined as the first episode of wheezing in children under two), nebulized epinephrine decreased hospitalization rate on day one by 33% (RR: 0.67; 95% CI: 0.50, 0.89; 4 trials; 920 participants). With the addition of glucocorticoids, there was a reduction of similar magnitude for hospitalization rate within seven days (RR: 0.65; 95% CI: 0.44, 0.95; 1 trial; 400 participants). For inpatients, nebulized epinephrine versus bronchodilator and 3% hypertonic saline versus 0.9% saline each decreased length of stay: epinephrine decreased length of stay by seven hours (MD: − 0.28; 95% CI: − 0.46, − 0.09; 4 trials; 261 participants), and 3% hypertonic saline decreased length of stay by 28 hours (MD: − 1.16; 95% CI: − 1.55, − 0.77; 4 trials; 282 participants). Outpatients treated with epinephrine or epinephrine and glucocorticoid combined both had significantly lower clinical scores at 60 minutes (SMD: − 0.45; 95% CI: − 0.66, − 0.23; 4 trials; 900 participants, and SMD: − 0.34; 95% CI: − 0.54, − 0.14; 1 trial; 399 participants). For inpatients, epinephrine versus bronchodilator led to a significantly lower clinical score at both 60 minutes (SMD: − 0.79; 95% CI: − 1.45, − 0.13; 4 trials; 248