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

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.

METHODS

Open-label, prospective study.

METHODS

The emergency department of a university medical center.

METHODS

Ten patients with moderate to severe exacerbation of asthma.

METHODS

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

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.