RESUMEN
BACKGROUND: Tachycardia and tachyarrhythmias are associated with increased morbidity and mortality in adult patients in the ICU. This study examines the effects of nebulized bronchodilator therapy (albuterol and ipratropium) on heart rate and arrhythmias in this population and tests the proposition that levalbuterol is safer than albuterol in that regard. METHODS: The design was a randomized, single-blind, crossover, prospective study in 70 critically ill adult patients treated with nebulized bronchodilators. Patients were randomized to nebulized albuterol alternating with levalbuterol every 4 to 6 h. Group A received albuterol 2.5 mg alternating with levalbuterol 0.63 mg. Group B received albuterol 2.5 mg alternating with levalbuterol 1.25 mg. All patients received nebulized ipratropium bromide with each treatment. Heart rate was recorded before and after each treatment. Cardiac rhythm was continuously monitored using electronic telemetry units. RESULTS: In group A, mean ± SD change in heart rate after albuterol 2.5 mg (n = 303) was 0.89 ± 4.5 beats/min compared with 0.85 ± 5.3 beats/min after levalbuterol 0.63 mg (n = 301) (P = .89). In group B (n = 114), heart rate decreased 0.16 ± 5.1 beats/min after albuterol 2.5 mg compared with an increase of 1.4 ± 5.4 beats/min after levalbuterol 1.25 mg (n = 118) (P = .03). Five events of arrhythmias (0.6%) occurred during the course of 836 treatments. Four consisted of occasional premature ventricular contractions. Only one patient stopped treatment because of a 5-beat run of ventricular tachycardia (one in 70 patients [1.4%]). CONCLUSIONS: In critically ill adult patients, nebulized albuterol and ipratropium does not cause significant tachycardia or tachyarrhythmias. Substitution of levalbuterol for albuterol to avoid tachycardia and tachyarrhythmias is unwarranted. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01151579; URL: www.clinicaltrials.gov.