Bronchiolitis in ED: Nebulized Hypertonic Saline/Epinephrine?

Source: Grewal S, Ali S, McConnell DW, et al. A randomized trial of nebulized 3% hypertonic saline with epinephrine in the treatment of acute bronchiolitis in the emergency department. Arch Pediatr Adolesc Med. 2009; 163:(11) 1007– 1012; doi: 10.1001/archpediatrics.2009.196To determine whether nebulized 3% hypertonic saline has a clinical benefit in infants with bronchiolitis, a randomized, double-blind, controlled trial was performed in the emergency department (ED) on 46 infants with mild to moderate bronchiolitis. All patients were selected from the pediatric ED at Stollery Children’s Hospital in Edmonton, Alberta, Canada. Infants aged 6 weeks to 12 months seen with a first episode of wheezing, clinical symptoms of a viral respiratory infection, an initial oxygen saturation of 85%–96%, and an initial Respiratory Distress Assessment Instrument (RDAI) score of 4 or higher were included in the study. The RDAI score ranges from 0 to 17 and is calculated based on wheezing type and location and retraction severity and location. Exclusion criteria included pre-existing cardiac or pulmonary disease, previous diagnosis of asthma by a physician, any use of bronchodilators prior to the current illness, language barrier, and no telephone access for follow-up.The selected infants were randomly assigned to receive either hypertonic saline containing 2.5 mL of 3% saline with 0.5 mL of 2.25% racemic epinephrine, or the same volume of normal saline (0.9% saline) with 2.25% racemic epinephrine. All were administered via a nebulizer driven by a 6 L/min flow of oxygen. A repeat dose could be given at the discretion of the ED physician. Measurements of oxygen saturation, respiratory rate, heart rate, and RDAI score were made immediately prior to administration of the aerosol, and at 30, 60, 90, and 120 minutes after administration. One patient in each group withdrew or was dropped. Baseline characteristics of the two groups were similar with regard to age, gender, family history of asthma, smoke exposure, respiratory syncytial virus positivity (82.6% and 81.8%, respectively, for the hypertonic saline and normal saline groups), and baseline respiratory rate.A discretionary second dose was administered in 56% (13/23) of the hypertonic saline group and 48% (11/23) of the normal saline (control) group. No differences between the two groups in respiratory distress, oxygen saturation, or returns to the ED (3/23 vs 4/23) were apparent. Additionally, while a difference with regard to hospital admission was noted between the hypertonic saline group (8/23) and the normal saline group (13/23), this difference did not reach statistical significance.The authors conclude that 3% hypertonic saline did not demonstrate the effectiveness in this ED setting that had been demonstrated in inpatient studies.While this study was unable to identify a significant benefit from one or two doses of 3% hypertonic saline during a two-hour period, the results differ from those of an ambulatory study of infants with bronchiolitis seen at the Pediatric and Adolescent Ambulatory Community Clinic of General Health Services of Petach-Tikva, Israel,1 which found a significant decrease in symptoms during the first two days from three-times-daily use, a result similar to that seen in three inpatient studies included in a Cochrane review.2 While there was no decrease in the rate of hospitalization in that study, it was low (6%–9%) in both groups. The current study found fewer hospitalizations in the 3% hypertonic saline group. While the differences in hospitalization were not statistically significant, the possibility of a type 2 error (accepting the absence of a population difference based on a relatively small sample) must be considered.The data available from the various studies now support routine use of 3% hypertonic saline with either epinephrine or a β2 agonist such as albuterol in hospitalized patients with the expectation of more rapid clinical improvement and a one-day decrease in hospital stay. Use in the ED is not yet routinely justified, but a larger study powered to examine further the potential for decreasing hospitalizations would be needed. For infants not requiring hospitalization, more rapid improvement in symptoms from hypertonic saline must be weighed against the expense and inconvenience of three-times-daily use of an aerosol for a self-limited problem with a low likelihood of requiring repeat emergent care or hospitalization. Although not yet studied, it would be of interest to see if there is any benefit to using hypertonic saline in more severe bronchiolitis patients at risk for or requiring assisted ventilation.