Beta2-agonists have questionable symptomatic effect in infants with acute
bronchiolitis, whereas inhaled, nebulized
racemic adrenaline, commonly used in Norway, appears (clinically) to be effective. Limited lung function observations during acute
bronchiolitis exists, and less for assessing possible effects inhaled
adrenaline. In this preliminary study, tidal flow-volume loops were measured in 16 infants with acute
bronchiolitis and seven healthy controls (mean age 7.9 and 4.4 months, respectively), with repeated measurements 15 min after inhaled nebulized
racemic adrenaline (4 mg diluted in 2 ml saline) in nine
bronchiolitis patients. The ratio of time to reach peak tidal expiratory flow to total expiratory time (tPTEF/tE) was significantly reduced in children with acute
bronchiolitis (mean, 95% CI) (0.08, 0.05-0.10) compared to controls (0.31, 0.18-0.43), with significant improvement after inhaled
racemic adrenaline 0.19 (0.13-0.25), parallel with significant clinical improvement. Lung function (tPTEF/tE) was reduced in infants with acute
bronchiolitis and improved significantly after inhaled
racemic adrenaline. Inhaled
racemic adrenaline is potentially an important alternative for treating infants with acute
bronchiolitis.