Effect of nebulized albuterol on serum potassium and cardiac rhythm in patients with asthma or chronic obstructive pulmonary disease.

STUDY OBJECTIVE: To evaluate the metabolic and cardiopulmonary effects of nebulized albuterol in patients suffering moderate to severe exacerbations of asthma or chronic obstructive pulmonary disease.

DESIGN: Open-label, prospective study.

SETTING: The emergency department of a university medical center.

PATIENTS: Ten patients with moderate to severe exacerbation of asthma.

INTERVENTIONS: Each patient received nebulized albuterol 2.5 mg for approximately 10 minutes.

MEASUREMENTS AND MAIN RESULTS: Serum potassium, heart rate and rhythm, blood pressure, and pulmonary function were measured before treatment and every 15 minutes for 2 hours after treatment. Serum potassium concentrations decreased significantly (p < 0.05) within 75 minutes after initiation of treatment, from a baseline value of 4.5 +/- 0.6 mEq/L (range 3.5-5.5 mEq/L) to 3.7 +/- 0.5 mEq/L (range 2.8-4.4 mEq/L) at the end of the collection period (120 minutes). Forced expiratory volume in 1 second significantly increased over time in patients with asthma (p < 0.05). No statistically significant changes in blood pressure, heart rate, or corrected QT intervals occurred. Pre-emergency department use of a beta 2-agonist by metered-dose inhaler was not associated with a decreased serum potassium on admission.

CONCLUSIONS: Nebulized beta 2-agonists are generally efficacious and safe in patients with acute bronchospasms. However, close monitoring of serum electrolytes, heart rate, and rhythm in patients at risk (elderly, those with pre-existing cardiac disease) is advised before these individuals receive repeat doses by continuous aerosol administration.