Objectives: a) to determine if continuous nebulization of albuterol is more effective than intermittent nebulization in the treatment of children with status asthmaticus and impending respiratory failure; b) to determine the effect of continuous nebulization and intermittent nebulization on duration of hospital stay and bedside respiratory therapy care.
Design: Prospective, randomized study.
Setting: A pediatric intensive care unit (ICU) in a university children's hospital.
Patients: Seventeen pediatric asthmatic patients with severe status asthmaticus, with impending respiratory failure (Woods asthma score > or = 5), and without evidence of cardiac or other preexisting lung disease were admitted to the pediatric ICU. The patients were randomized to receive continuous nebulization (n = 9) or intermittent nebulization (n = 8) of albuterol.
Interventions: The asthmatic patients were randomized into two groups. The continuous group received 0.3 mg/kg/hr of albuterol by continuous nebulization; the intermittent group received 0.3 mg/kg of albuterol over 20 mins every hour. All patients received aerosol therapy through the same delivery system.
Measurements: Responses to therapy were evaluated by following asthma score, arterial blood gas values, hemodynamics, FIO2, and arterial oxygen saturation initially and at 30 mins, 1 hr, 2 hrs, 4 hrs, then every 4 hrs for a 24-hr time period. Patients were determined to no longer be in impending respiratory failure when their asthma score was < 5 for four consecutive hours. Electrocardiograms, serum electrolyte values, and creatine phosphokinase total and MB fraction values were obtained before and after treatment. Hospital stay and respiratory therapy time, in relative value units (one relative value unit = 10 mins) were analyzed from data collected from therapist bedside flow sheets.
Results: The patient characteristics (demographics, hemodynamics, arterial blood gas values, asthma severity, corticosteroid use, theophylline, and beta 2-adrenergic receptor agonist administration) before entry into the study did not differ between groups. Patients in the continuous group improved more rapidly and were out of impending respiratory failure sooner than patients in the intermittent group (continuous group = 12 (median) hrs (range 4 to 24) vs. intermittent group = 18 (median) hrs (range 12 to 24; p = .03). Bedside respiratory therapy time evaluated by relative value units was less for patients who received continuous nebulization of albuterol (continuous group = 14 (median) relative value units (range 6 to 26) vs. intermittent group = 33 (median) relative value units (range 25 to 49; p = .001). Hospital stay was shorter for patients who received continuous nebulization of albuterol (continuous group = 80 [median] hrs [range 51 to 173] vs. intermittent group = 147 [median] hrs [range 95 to 256]; p = .043). Hemodynamics, serum potassium, and creatine phosphokinase concentrations did not differ before and after the study in either group.
Conclusions: In children with impending respiratory failure due to status asthmaticus, continuous nebulization of albuterol is safe and results in more rapid clinical improvement than intermittent nebulization. Respiratory therapy required at the bedside and duration of hospital stay were substantially less for patients receiving continuous nebulization of albuterol, which suggests that continuous nebulization of albuterol is more cost effective than intermittent nebulization.