Prospective randomized double-blind study comparing L-epinephrine and racemic epinephrine aerosols in the treatment of laryngotracheitis (croup).

Aerosolized racemic epinephrine, but not L-epinephrine, is commonly used in treating croup. The efficacy and adverse effects of nebulized racemic and L-epinephrine in the treatment of laryngotracheitis were compared. Children 6 months to 6 years of age with a croup score of 6 or above were assigned in a randomized double-blind fashion to receive either racemic (n = 16) or L-epinephrine (n = 15) aerosols. Croup score, heart rate, blood pressure, respiratory rate, fraction of inspired oxygen, and oxygen saturation were recorded before treatment and at 5, 15, 30, 60, 90, and 120 minutes after the aerosol. Patients in both groups showed significant transient reduction of the croup score and respiratory rate following the aerosol (P less than .001), but there were no differences between treatment groups when croup score, heart rate, blood pressure, and respiratory rate were assessed over time. It is concluded that L-epinephrine is at least as effective as racemic epinephrine in the treatment of laryngotracheitis and does not carry the risk of additional adverse effects. L-Epinephrine is also more readily available worldwide, is less expensive, and can be recommended for this purpose.