THE CLINICAL EFFICACY OF NEBULIZED RACEMIC EPINEPHRINE AND ALBUTEROL IN ACUTE BRONCHIOLITIS

Objective: To investigate whether nebulized racemic epinephrine or alb uterol improves respiratory distress in infants with acute bronchiolit is. Design: A randomized, placebo-controlled, double-blind study. Sett ing: A university hospital providing primary hospital care for all ped iatric patients in a defined area. Patients: One hundred consecutive i nfants younger than 24 months treated in the hospital for acute bronch iolitis. Intervention: The patients received two inhalations at 30-min ute intervals: racemic epinephrine followed by physiologic saline (REP group; n=24), albuterol followed by physiologic saline (AP group; n=2 7), physiologic saline followed by racemic epinephrine (PRE group; n=2 4), and physiologic saline followed by albuterol (PA group; n=25). All patients received intramuscular epinephrine 60 minutes after the begi nning of the study. Main Outcome Measures: Oxygen saturation, respirat ory rate, and two clinical scores were used: one based on wheezing and retractions (Respiratory Distress Assessment Instrument) and the othe r based on changes in wheezing, retractions, and respiratory rate (Res piratory Assessment Change Score). Main Results: During the study, the re were no significant differences among the four groups in clinical s cores, oxygen saturations, and respiratory rates. Mean Respiratory Dis tress Assessment Instrument scores improved significantly within the R EP, PRE, and AP groups 15 minutes after the first inhalation. In only the REP group, which received racemic epinephrine, the confidence limi ts did not overlap. A comparison of paired data of each patient reveal ed that the difference in Respiratory Assessment Change Score was sign ificant between racemic epinephrine and physiologic saline, but not be tween albuterol and physiologic saline. Intramuscular epinephrine sign ificantly improved Respiratory Distress Assessment Index scores in tho se groups treated earlier with racemic epinephrine (REP and PRE groups ). No significant adverse effects were seen in any group or at any pha se of the study. Conclusions: Elimination of hypoxia by supplemental o xygen and moistening of inspired air relieve the symptoms of acute acu te bronchiolitis. Nebulized racemic epinephrine and albuterol are safe and useful in the treatment of acute bronchiolitis. Improvements in s ymptom scores at 15 minutes favor the use of racemic epinephrine. As t he action of epinephrine is short, the effect can be increased by repe ated inhalations.