Nebulized albuterol delivery is associated with decreased skeletal muscle strength in comparison with metered-dose inhaler delivery among children with acute asthma exacerbations.

Objective: Albuterol is a β2-agonist and causes an intracellular shift of potassium from the interstitium. Whole-body hypokalemia is known to cause skeletal muscle weakness, but whether this occurs as a result of hypokalemia from the intracellular shift during albuterol treatment is unknown. We sought to determine if albuterol total dose or route of administration (nebulization and/or metered-dose inhaler) is associated with skeletal muscle weakness.

Methods: This was a prospective observational study using convenience sampling. Skeletal muscle strength was measured before and after 1 hour of albuterol treatment using a hand-grip dynamometer in participants aged 5-17 years with acute asthma exacerbation in the emergency department. We examined associations of albuterol dose and route of administration with changes in grip strength.

Results: Among 50 participants, 10 received continuous albuterol by nebulizer and 40 received albuterol by metered-dose inhaler. The median (interquartile range) in change of grip was -7.8% (interquartile range, -23.3, +5.1) for those treated with a nebulizer and +2.4% (interquartile range, -5%, +12.7%) for those treated with a metered-dose inhaler ( = 0.036 for the difference). In a multiple linear regression model adjusted for the pretreatment Acute Asthma Intensity Research Score and age, participants treated with a nebulizer had a 12.9% decrease in skeletal muscle strength compared with those treated with a metered-dose inhaler.

Conclusion: Higher doses of albuterol administered via nebulization result in decreased skeletal muscle strength in patients with acute asthma; whereas, albuterol administration via metered-dose inhalers showed no effect on skeletal muscle strength.