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 6 h 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.