Infant Bronchiolitis: 3% Saline No Benefit vs Normal Saline

Nicola M. Parry, DVM

November 09, 2015

For infants hospitalized with acute bronchiolitis, nebulized hypertonic saline (HS) without adjunctive bronchodilators is safe but not superior to 0.9% normal saline (NS) in reducing length of stay in the hospital, according to the results of a randomized clinical trial.

"This study suggests there is no utility for the routine use of 3% HS alone in treating infants hospitalized with bronchiolitis as compared with NS," Alyssa H. Silver, MD, assistant professor of pediatrics in the Division of Pediatric Hospital Medicine, Albert Einstein College of Medicine, Bronx, New York, and colleagues write. They report the trial results in an article published online November 9 in Pediatrics.

Bronchiolitis is the most common cause of hospitalization among infants in the United States and contributes to significant economic burden, the authors note. Supportive care remains the cornerstone of current management, and it has been suggested that nebulized 3% HS may reduce the severity of symptoms. However, previous studies have reported conflicting results.

"Initial studies using HS for infants hospitalized with bronchiolitis suggest decreased [length of stay] and improved severity scores," the study authors write. In addition, a 2013 Cochrane review suggested that nebulized HS may be considered a safe and effective treatment of infants with mild to moderate bronchiolitis, as did the results of a systematic review and meta-analysis published in the October issue of Pediatrics. However, "[s]ubsequent studies suggest no benefit from HS for inpatients, despite concomitant use of bronchodilators in all but one, which differed by being an open study," the authors add.

Therefore, they aimed to investigate the efficacy and safety of HS without confounding from bronchodilators.

The researchers conducted a prospective, randomized, double-blind, controlled, parallel-group study of 227 infants younger than 12 months who were hospitalized with bronchiolitis, including those with a history of previous wheeze. They excluded infants who were receiving continuing treatment of status asthmaticus, as well as infants with chronic cardiopulmonary disease (including chronic lung disease) and those who had received nebulized HS in the 12 hours before presentation.

Infants were randomly assigned to receive 4 mL nebulized 3% HS or 4 mL 0.9% NS every 4 hours from enrollment until hospital discharge. Because of the theoretical risk for bronchospasm with HS, the investigators used the validated Respiratory Distress Assessment Instrument to assign patients a score before and 30 minutes after the first study treatment.

Median length of stay did not differ significantly between the HS and NS groups by intention-to-treat analysis (2.1 vs 2.1 days; P = .73) or per protocol analysis (2.0 [interquartile range (IQR), 1.3 - 3.3 days] vs 2.0 [IQR, 1.2 - 3.0 days] days; P = .96). Similarly, 7-day readmission rates (4.3% vs 3.1%; P = .77), total adverse events (15% vs 12%; P = .67), and clinical worsening events, defined as transfer to the pediatric intensive care unit or a Respiratory Distress Assessment Instrument increase of 4 or more points (9% vs 8%; P = .97), did not differ significantly between the 2 groups.

The authors note that although the data show that HS is safe for use in this population, including those patients with a history of wheeze, there is no added benefit beyond NS. "This study suggests there is no utility for the routine use of 3% HS alone in treating," they conclude.

Although they acknowledge the single-center nature of this study was a limitation, they emphasize that length of stay was comparable with findings in other US studies on bronchiolitis.

"Bronchiolitis admissions consume substantial US health care resources, surpassing $1.7 billion annually in charges. It is imperative that research focus on using effective treatments for these infants, minimizing bothersome interventions without benefit," the authors write.

"Our negative study may help reduce use of HS and thereby decrease hospitalization costs and unnecessary resource utilization," they conclude.

The authors received no external funding for this study and have disclosed no relevant financial relationships.

Pediatrics. Published online November 9, 2015.


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