Comparison of the effects of nebulized terbutaline with or without intravenous betamethasone on exhaled nitric oxide in children with acute asthma attack

Background and Purpose: Exhaled nitric oxide (eNO), a non-invasive marker that reflects the degree of airway inflammation, may be useful for assessing the response to anti-inflammatory treatment of asthma. The purpose of this randomized prospective study was to compare the effect of a nebulized terbutaline plus a single intravenous dose of betamethasone at baseline followed by a second of terbutaline at 6h with the effect of the same protocol of nebulized terbutaline alone on airway inflammation of acute asthmatic children as demonstrated by eNO levels. Methods: Children visiting the emergency department due to acute asthma attack were recruited. All enrolled patients had fluorescent assay-proven hypersensitivity to Dermatophagoides pteronyssinus. Patients were randomized to receive either nebulized terbutaline plus intravenous betamethasone (experimental group, n = 11) or nebulized terbutaline alone (control group, n = 11) at baseline followed by a second dose of nebulized terbutaline alone 6 h later. Results: Exhaled NO concentrations were significantly reduced in the experimental group at 7 h (40.25 ± 12.43 vs 28.88 ± 18.02 ppb; p=0.005) and 12 h (40.25 ± 12.43 vs 30.11 ± 18.16 ppb; p=0.007) after treatment. The eNO level in the experimental group was also reduced at 7 h (28.88 ± 18.02 vs 38.12 ± 16.50 ppb; p=0.034) and 12 h (30.11 ± 18.16 vs 39.36 ± 17.63 ppb; p=0.035) compared to the control group. The change of eNO concentration was correlated to the change of peak expiratory flow rate (PEFR) [r = -0.678; p=0.022] and pulmonary index scores (r = 0.606; p=0.048) at 7 h after treatment in the betamethasone group. Conclusion: Nebulized terbutaline given at baseline and 6 h later was significantly more effective in improving PEFR and asthmatic symptoms (pulmonary index scores) for at least 12 h when the initial dose was administered in combination with intravenous betamethasone.