Inhaled β2-Agonist Therapy Increases Functional Residual Capacity in Mechanically Ventilated Children With Respiratory Failure.

OBJECTIVES

To test the hypothesis that in mechanically ventilated children with respiratory failure, aerosolized albuterol modifies functional residual capacity, lung mechanics, oxygen consumption, and hemodynamics.

DESIGN

Prospective, self-control clinical trial.

SETTING

A 24-bed PICU in a quaternary care, academic children's hospital.

PATIENTS

25 children (age range, 1-18 yr) undergoing mechanical ventilation to treat respiratory failure. Entry criteria included previously prescribed inhaled β2 agonists. Physiologic measurements were performed prior to and 20 minutes after administration of aerosolized albuterol solution. Functional residual capacity was determined via nitrogen washout.

INTERVENTIONS

Functional residual capacity, oxygen consumption, respiratory mechanics, and vital signs were measured were measured prior to and 20 minutes after administration of aerosolized albuterol solution. Functional residual capacity was determined via nitrogen washout.

MEASUREMENT AND MAIN RESULTS

At baseline, functional residual capacity is only 53% of predicted. After aerosolized albuterol, functional residual capacity increased by 18.3% (p = 0.008). Overall, aerosolized albuterol had no effect on airway resistance. However, in patients with an endotracheal tube size of more than or equal to 4.0 mm, resistance decreased from 33 ± 3 to 25 ± 3 (p < 0.02). Inhaled albuterol administration had no effect on oxygen consumption despite an increase in heart rate from 116 ± 2 to 128 ± 2 beats/min (p < 0.0001).

CONCLUSIONS

In pediatric patients with respiratory failure, aerosolized albuterol increases functional residual capacity without a decrease in resistance. In infants and children, aerosolized albuterol might favorably enhance pulmonary mechanics and thereby represent a novel strategy for lung recruitment in children with respiratory failure.