Nebulized Hypertonic Saline vs Normal Saline in Infants With Acute Bronchiolitis

Infants with acute bronchiolitis treated with nebulized hypertonic saline may experience a decreased length of stay and improved clinical severity scores if hospitalized as an inpatient and have a reduced risk of requiring hospitalization if treated as an outpatient or in the emergency department, according to a study published in the Cochrane Database of Systematic Reviews.

Researchers identified 17 randomized and quasi-randomized parallel-group controlled trials that met inclusion criteria to be added to the 11 trials included in a 2013 update, totaling 28 trials consisting of 4195 participants. The primary outcomes of this study were length of hospitalization for inpatient infants diagnosed with acute bronchiolitis and rate of hospitalization of infants treated as outpatients or at an emergency department who were treated with hypertonic saline (≥3%) compared with nebulized 0.9% saline.

Infants were placed into groups consistent with the percentage of hypertonic saline they received. The quality of studies was assessed using the 5 factors of the GRADE approach (study limitations, consistency of effect, imprecision, indirectness, and publication bias). Subgroup analysis was performed based on availability of data (hospital length of stay, virology, upper age limits, hypertonic saline concentration, interval administration, coadministration with bronchodilators, length of stay in the control group, publication year, and selection bias risk) to assess for heterogeneity.

Study results demonstrated a statistically significantly shorter length of stay in infants treated with nebulized hypertonic saline compared with those treated with 0.9% saline, with a mean difference (MD) of –0.41 days (95% CI, –0.75 to –0.07; P =.02; low quality evidence). In infants treated in the outpatient and emergency department settings, treatment with hypertonic saline reduced the risk for hospitalization by 14% overall (pooled risk ratio [RR], 0.86; 95% CI, 0.76-0.98; P =.02; moderate quality evidence). Heterogeneity was significant in the inpatient studies investigated and moderate in the outpatient and emergency department studies investigated and persisted despite subgroup analysis. 

Postinhalation scores for infants treated with nebulized hypertonic saline were statistically significantly lower than in those treated with 0.9% saline for days 1, 2, and 3 of treatment (MD –0.77; 95% CI, –1.18 to –0.36; P ≤.001; MD, –1.28; 95% CI, –1.91 to –0.65; P <.001; MD, –1.43; 95% CI, –1.82 to –1.04; P <.001). 

Secondary outcomes of this review found that in infants treated as outpatients (n=65), the clinical severity scores were statistically significant on the first, second, and third days of treatment in those treated with 3% hypertonic saline vs normal saline (MD, –1.28; 95% CI, –1.92 to –0.64; P <.001; MD, –2.0; 95% CI, –2.93 to  –1.07; P <.001, and MD, –2.64; 95% CI, –3.85 to –1.43; P <.001, respectively). A reduction in clinical severity scores of inpatient infants treated with hypertonic saline was also observed (pooled MD, –0.82; 95% CI, –1.25 to –0.38; P =.005; I² = 67%), and 2 studies of emergency department treatment demonstrated a superiority of hypertonic saline over normal saline. 

Readmission rates were not significantly reduced in infants treated with hypertonic saline, nor were there any differences in respiratory rate, heart rate duration of oxygen supplementation, need for add-on treatment, or radiologic scores in those treated with hypertonic vs normal saline. At least one adverse event was reported in 11 of the 24 trials that presented safety data. Adverse events were mild and resolved spontaneously. No adverse events were reported in the other 13 trials.

Differences in trials published before 2013 and the current review included a decrease in virologic evidence (86% and 30% of trials, respectively) and an increase in recorded mean length of stay (0% and 40% of trials, respectively). Finally, the reduction in risk for hospitalization in patients treated as outpatients and in emergency departments was found to be 14% (RR, 0.86; 95% CI, 0.76-0.98) compared with a 37% risk in the 2013 review, which was not statistically significant. The 2013 review included fewer trials and less data.

Investigators concluded that the review of current evidence supports the use of nebulized hypertonic saline in infants hospitalized with acute viral bronchiolitis, as it may reduce length of stay and has a good safety profile. In addition, treatment with nebulized hypertonic saline may also reduce the risk for hospitalization in infants treated as outpatients and in emergency departments. 

Reference

Zhang L, Mendoza-Sassi RA, Wainwright C, Klassen TP. Nebulised hypertonic saline solution for acute bronchiolitis in infants. Cochrane Database Syst Rev. 2017;12:CD006458.